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  • 201.
    Magnevall, Martin
    et al.
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Lundblad, Mikael
    Ahlin, Kjell
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Broman, Göran
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    High Frequency Measurements of Cutting Forces in Milling by Inverse Filtering2012Inngår i: Machining science and technology, ISSN 1091-0344, E-ISSN 1532-2483, Vol. 16, nr 4, s. 487-500Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Accurate estimates of cutting forces are important in the evaluation of different cutting tool geometries and concepts. However, dynamic influences from the measurement system affect the result, which can make the obtained cutting force data erroneous and misleading. This article presents a method to obtain an inverse filter which compensates for the dynamic influences of the measurement system. Using this approach, unwanted dynamic effects of the measurement system can be counteracted, making it possible to retain information related to the cutting forces contained in the high frequency region. The advantage of the proposed method is illustrated by comparing simulated, inverse- and low-pass filtered forces to unfiltered forces under different cutting conditions. The results show that inverse filtering increases the usable frequency range of the force dynamometer and thereby provide more reliable results compared to both low-pass and unfiltered forces.

  • 202.
    Massimo, Panarotto
    et al.
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Åsa, Ericson
    Tobias, Larsson
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Intangibles in Design of PSS Value Propositions2013Inngår i: The Philosopher's Stone for Sustainability / [ed] Yoshiki, Shimomura; Koji, Kimita, Berlin, Heidelberg: Springer , 2013, s. 85-90Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Product-service systems (PSS), or value propositions, are foreseen to bring about challenges in product development. Traditionally, engineers normally manage tangible elements in relation to products, and are lacking approaches to deal with the intangibles incorporated in PSS development. The purpose of the paper is to elaborate on and propose a framework for value assessment and a simulation approach. Conceptual examples are used to discuss the proposed framework, and a contribution of the paper is that it exemplifies the reasons why intangible value have to be addressed more directly in industry in general and in PSS in particular.

  • 203. Mfoumou, Etienne
    Low Frequency Acoustic Excitation and Laser Sensing of Vibration as a Tool for Remote Characterization of Thin Sheets2008Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    There is a need to monitor the existence and effects of damage in structural materials. Bulk components provide a much publicized example, but the need exists in a variety of other structures, such as layered materials used in food packaging industries. While several techniques and models have been proposed for characterization and condition monitoring of bulk materials, less attention has been devoted to thin films having no bending rigidity. This study is therefore devoted to the development of a new method for remote acoustic non-destructive testing and characterization of thin films used in food packaging materials or similar structures. A method for assessing the strength in the presence of crack of thin layers used in food packaging is first presented using a modified Strip Yield Model. Resonance frequency measurement is then introduced and it is shown, at low frequency range, less than 2kHz, that a change in the physical properties such as a reduction in stiffness causes detectable changes in the modal properties, specifically in the resonance frequency. This observation leads to the implementation of a method for damage severity assessment on sheet materials, supported by a new theory illustrating the feasibility of the detection of inhomogeneity in form of added mass, as well as damage severity assessment, using a measurement of the resonance frequency shift. A relationship is then established between the resonance frequency and the material’s elastic property for single layers as well as for laminates, which yields a new modality for sheet materials remote characterization. Further, the method has allowed demonstrating that thin sheets having no bending stiffness exhibit a slow non-equilibrium dynamics when slightly loaded within their elastic region and monitored at constant strain. We found that the resonance frequency shifts downward in response to a conditioning strain and to the number of cycles. This is an indication of a long-time slow dynamics relaxation, similar to that observed on bulk materials of many types. Differences and similarities in the setup as well as features observed are pointed out in this work. This type of measurement is important for the fundamental understanding of material dynamics and for further development of theories on thin sheets dynamics. The result of this study is the foundation of a method, based on low-frequency acoustic excitations and laser detection, for non-contact nondestructive testing and characterization of sheet materials.

  • 204. Mfoumou, Etienne
    Remote Acoustic Characterization of Thin Sheets2006Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    There is a need to monitor the existence and effects of damage in structural materials. Aircraft components provide a much publicized example, but the need exists in a variety of other structures, such as layered materials used in food packaging industries. While several techniques and models have been proposed for material characterization and condition monitoring of bulk materials, less attention has been devoted to thin sheets having no flexural rigidity. This study is therefore devoted to the development of a new method for acoustic Non-Destructive Testing (NDT) and material characterization of thin sheets used in food packaging materials or similar structures. A method for assessing the strength in the presence of crack of thin sheets used in food packaging is first presented using a modified Strip Yield Model (SYM). Resonance frequency measurement is then introduced and it is shown, at low frequency range (less than 2kHz), that a change in the physical properties such as a reduction in stiffness resulting from the onset of cracks or loosening of a connection causes detectable changes in the modal properties, specifically the resonance frequency. This observation leads to the implementation of a simple method for damage severity assessment on sheet materials, supported by a new theory illustrating the feasibility of the detection of inhomogeneity in form of added mass, as well as damage severity assessment, using a measurement of the frequency shift. A relationship is then established between the resonance frequency and the material’s elastic property, which yields a new modality for sheet materials remote characterization. The result of this study is the groundwork of a low-frequency vibration-based method with remote acoustic excitation and laser detection, for nondestructive testing and material characterization of sheet materials. The work also enhances the feasibility of the testing and condition monitoring of real structures in their operating environment, rather than laboratory tests of representative structures. The sensitivity of the new experimental approach used is liable to improvement while being high because the frequency measurement is one of the most accurate measurements in physics and metrology.

  • 205. Mfoumou, Etienne
    et al.
    Hedberg, Claes
    Kao-Walter, Sharon
    Static Versus Low Frequency Dynamic Elastic Modulus Measurement of Thin Films2006Inngår i: Electronical Journal of Technical Acoustics, ISSN 1819-2408, E-ISSN 1819-2408, nr 17Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new experimental technique for evaluating Young’s (or elastic) modulus of a vibrating thin film from a dynamic measurement is presented. The technique utilizes bending resonance from a remote acoustic excitation to determine Young’s modulus. Equations relating the natural frequencies to the mechanical properties are obtained, and Young’s modulus is subsequently determined. Young’s modulus values from dynamic test are compared with those (static) obtained by a standard tensile test, and consistent results are obtained. The proposed technique is relatively simple and could be used to determine Young’s modulus of a wide variety of sheet materials initially having no bending stiffness. It can also be used for determining other mechanical properties, such as compliance methods in connections with fracture mechanical testing, fatigue and damage measurements. This work emphasizes the feasibility of a damage assessment of components in-service by evaluating changes in the material characteristics.

  • 206. Mfoumou, Etienne
    et al.
    Hedberg, Claes
    Kao-Walter, Sharon
    Vibration-Based Damage Detection and Evaluation of Sheet Materials using a Remote Acoustic Excitation2008Inngår i: Acoustical Physics, ISSN 1063-7710 (print) 1562-6865 (online) , Vol. 54, nr 1, s. 127-134Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A simple method of damage severity assessment on sheet materials is suggested and proved by theory and experiment. The investigated defect types are in forms of added mass and crack. The method is based on the frequency shift measurement of a material vibrating as a membrane subjected to static tension and irradiated by an acoustic wave. It is shown both theoretically and experimentally that the natural frequency of the damaged membrane is shifted relative to its position in the ideal material. A local increase in thickness (or addition of mass) shifts the natural frequency down, while a crack shifts the frequency up. The method can be considered as acoustic weighting through the frequency shift. The sensitivity of this method can be high because frequency measurement is one of the most accurate measurements in physics and metrology.

  • 207. Mfoumou, Etienne
    et al.
    Hedberg, Claes
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Kao-Walter, Sharon
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Narayanswamy, S.
    A New Method of Acoustical Remote Evaluation of Defective Structures and Material Characterization2007Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The feasibility of a remote monitoring of structures for a progressive damage assessment as well as material characterization using a simple and inexpensive experimental setup is discussed. The method is based on a remote acoustic excitation of transverse vibrations on a membrane using an ordinary broadband low frequency loudspeaker, and the measurement of the response using a Laser Doppler Vibrometer (LDV). Theoretical modeling is also developed to correlate the experimental results obtained, and this yields a new method for Non Destructive Testing (NDT) of sheet-like materials. The function generator provides an input voltage of a sine signal to the loudspeaker, and laser detection of the surface vibrational response of the sample is accomplished with the laser vibrometer.

  • 208. Mfoumou, Etienne
    et al.
    Kao-Walter, Sharon
    Fracture Toughness Testing of Non Standard Specimens2004Rapport (Annet vitenskapelig)
    Abstract [en]

    The fracture behavior of the main layers used in food packaging material is studied. Investigations include aluminium foil (9μm), paper board (100 μm) and Low Density Polyethylene (27 μm). The plane stress fracture toughness of each layer is derived based on a centered crack panel. Different crack sizes have been tested. A compromise (crack length) was found, at which Strip Yield Model as well as Linear Elastic Fracture Mechanics allow the validation of experimental results. Meanwhile, accurate results are obtained using the Strip Yield Model with a geometric correction. The result is also used to evaluate crack initiation from a notch when all three layers are laminated.

  • 209. Mfoumou, Etienne
    et al.
    Kao-Walter, Sharon
    Hedberg, Claes
    Fracture Mechanism and Acoustic Damage Analysis of Thin Materials2005Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The fracture behavior of paper board (100 μm) used in food packaging material is studied. The plane stress fracture toughness is measured based on a centered crack panel. Different crack sizes have been tested. A compromise (crack length) was found, at which Strip Yield Model as well as Linear Elastic Fracture Mechanics allow the validation of experimental results. Meanwhile, accurate results are obtained using the Strip Yield Model with a geometric correction. Besides, detection of damage in food packaging material is an interesting feature in quality control of the product. Therefore the material is investigated using an acoustic method. The method consists of a vibration-based damage assessment and leads to a first level differentiation between damaged and non-damaged specimens. The fracture behavior of paper board (100 μm) used in food packaging material is studied. The plane stress fracture toughness is measured based on a centered crack panel. Different crack sizes have been tested. A compromise (crack length) was found, at which Strip Yield Model as well as Linear Elastic Fracture Mechanics allow the validation of experimental results. Meanwhile, accurate results are obtained using the Strip Yield Model with a geometric correction. Besides, detection of damage in food packaging material is an interesting feature in quality control of the product. Therefore the material is investigated using an acoustic method. The method consists of a vibration-based damage assessment and leads to a first level differentiation between damaged and non-damaged specimens.

  • 210. Mfoumou, Etienne
    et al.
    Kao-Walter, Sharon
    Hedberg, Claes
    Remote Acoustic Monitoring of Thin Laminates2007Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Understanding the change in material properties in time is necessary for in-service diagnosis of structures and prevention of accidents. Therefore, a new experimental technique for evaluating Young’s (or elastic) modulus of a vibrating thin sheet from a dynamic measurement is presented. The technique utilizes bending resonance from a remote acoustic excitation. Equations relating the natural frequencies to the mechanical properties are obtained, and Young’s modulus is subsequently determined experimentally using the implemented dynamic measurement method. Young’s modulus values from the dynamic test are then compared with those (static) obtained by a standard tensile test and those obtained by the theory of laminated materials. The proposed technique appears relatively simple and is applied in this paper to laminates initially having no (or negligible) bending stiffness, and used in packaging industries. This work emphasizes the feasibility of a remote condition monitoring of components in-service by evaluating changes in the material properties.

  • 211. Mfoumou, Etienne
    et al.
    Rudenko, Oleg
    Hedberg, Claes
    Kao-Walter, Sharon
    Acoustical measurement accompanying tensile test: new modality for non-destructive testing and characterization of sheet materials2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A series of uniaxial tensile tests was performed for sheet materials like paperboard, polyethylene and packing layered composites. These sheets can be considered as membranes. In parallel with a tensile test, the natural frequency was measured through an acoustical excitation. Firstly, it was shown both theoretically and experimentally that, at a given load, the frequency is sensitive to the local deviation in the standard thickness or to the presence of cracks inside the material. It means that this acoustic measurement can be used as one of the methods of damage assessment, or nondestructive testing in general. Secondly, the resonance frequency shift was continuously monitored for increasing strain on polyethylene and paperboard, and the curves obtained were compared to the stress-strain curves for material characterization. They were not the same and showed a non-monotonic stiffness variation for the polyethylene. It was shown that the resonance frequency shift measurement can successfully replace the stress-strain curve for material characterization under tensile test. During a long time under load an irreversible plastic deformation of the sample takes place, and the frequency shift can also serve as a new method for evaluating the residual strain of the material.

  • 212. Monceaux, Anne
    et al.
    Kossman, Mario
    Wiseall, Steve
    Bertoni, Marco
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    Isaksson, Ola
    Eres, Hakki Murat
    Bertoni, Alessandro
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    Rianantsoa, Ndrianarilala
    Overview of Value Driven Design Research: Methods, Applications and Relevance for Conceptual Design2014Inngår i: Insight, ISSN 2156-4868, nr DecemberArtikkel i tidsskrift (Fagfellevurdert)
  • 213.
    Motamediyan Dehkordi, Farnaz
    et al.
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Thompson, Anthony
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för strategisk hållbar utveckling.
    Larsson, Tobias
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Impacts of project-overload on innovation inside organizations: Agent-based modeling2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Market competition and a desire to gain advantages on globalized market, drives companies towards innovation efforts. Project overload is an unpleasant phenomenon, which is happening for employees inside those organizations trying to make the most efficient use of their resources to be innovative. But what are the impacts of project overload on organization’s innovation capabilities? Advanced engineering teams (AE) inside a major heavy equipment manufacturer are suffering from project overload in their quest for innovation. In this paper, Agent-based modeling (ABM) is used to examine the current reality of the company context, and of the AE team, where the opportunities and challenges for reducing the risk of project overload and moving towards innovation were identified. Project overload is more likely to stifle innovation and creativity inside teams. On the other hand, motivation on proper challenging goals are more likely to help individual to alleviate the negative aspects of low level of project overload

  • 214.
    Myrén, Marcus
    et al.
    Blekinge Tekniska Högskola, Institutionen för maskinteknik.
    Olsson, Jörgen
    Blekinge Tekniska Högskola, Institutionen för maskinteknik.
    Modal Analysis of Exhaust System1999Annet (Annet vitenskapelig)
    Abstract [en]

    A modal analysis is performed on an exhaust system for cars. Natural frequencies and mode shapes are correlated between experimental and finite element models. MAC-values are calculated. Theories and guidelines for modal analyses of exhaust systems are discussed.

  • 215. Nilsson, Susanne
    et al.
    Wallin, Johanna
    Benaim, Andre
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Annosi, Maria Carmela
    Berntsson, Richard
    Ritzén, Sofia
    Magnusson, Mats
    Re-thinking Innovation Measurement to Manage Innovation-Related Dichotomies in Practice2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Innovation performance measurement has developed from focusing on issues of control and monitoring towards a more supportive role for managers on a strategic, informative and motivational level. Despite its potential to facilitate innovation management measuring provides a challenge in practice not the least when a company has the ambition to manage both radical and incremental innovation. This paper, based on literature review with empirical illustrations from three case studies, argues that these issues derives from the need to manage a number of dichotomies which are present due to the essential differences associated to each type of innovation. These dichotomies are related to time, uncertainty, flexibility and control. The implications on the design and use of an innovation performance measurement system are explored and analyzed through the lens of dichotomies. The study contributes to the innovation measurement theory and provides basis for an analytical framework aiming to support the design and implementation of innovation performance measurement in practice.

  • 216.
    Nopparat, Nanond
    et al.
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Kianian, Babak
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Thompson, Anthony
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för strategisk hållbar utveckling.
    Larsson, Tobias
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Resource Consumption in Additive Manufacturing with a PSS Approach2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Since the 1980’s, additive manufacturing (AM) has gradually advanced from rapid prototyping applications towards fabricating end consumer products. Many small companies may prefer accessing AM technologies through service providers offering production services as result-oriented Industrial Product-Service System (IPSS) rather than investing in their own production line. This study investigated potential benefits of IPSS using system dynamics modeling to study resource demands between two situations: one where an IPSS approach is used and one that is the traditional ownership of production equipment. This study concluded that AM service providers with demand-varying customers could increase service performance and maximize use of production equipment.

  • 217. Ny, Henrik
    Strategic Life-Cycle Modeling and Simulation for Sustainable Product Innovation2009Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Many specific methods and tools have been developed to deal with sustainability problems. However, without a unifying theory it is unclear how these relate to each other and how they can be used strategically. A Framework for Strategic Sustainable Development (FSSD) is being developed to cover this need for clarity and structure. It includes backcasting from a principled definition of sustainability as a key feature. The aim of this thesis is to study how this framework can guide the use and improvement of detailed methods and tools, in particular to support sustainable product innovation (SPI). First, a new strategic life-cycle management approach is presented, in which the selection of aspects to be considered are not based on typical down-stream impact categories, but on identified major violations of sustainability principles. Ideas of how this approach can inform various specific methods and tools are also presented, as a basis for an integrated “toolbox” for SPI. As part of such, a new “template” approach for sustainable product development (TSPD) is developed through a sustainability assessment case study of TVs. That study indicates that this approach can create a quick and strategically relevant overview of critical sustainability aspects of a product, as well as facilitate communication between top management, product developers and external stakeholders. Based on such an assessment, it is sometimes necessary to go deeper into details, including the use of specific engineering methods and tools. To facilitate a coordinated assessment of sustainability aspects and technical aspects, an introductory procedure for sustainability-driven design optimization is suggested trough a water jet cutting case study. Equally important, to get a breakthrough for SPI, it is essential to integrate sustainability aspects into the overall decision-making process at different levels in companies. An approach to assessing sustainability integration in strategic decision systems is therefore also developed through a case study involving several companies. Finally, the integration between the FSSD and general systems modeling and simulation (SMS) is discussed and tested in another water jet cutting case study. It is shown feasible to start with the FSSD to create lists of critical flows and practices, ideas of long term solutions and visions, and a first rough idea about prioritized early investments. After that, SMS can be applied to study the interrelationships between the listed items, in order to create more robust and refined analyses of the problems at hand, possible solutions and investment paths, while constantly coupling back to the sustainability principles and guidelines of the FSSD. This research shows that the combination of the FSSD with detailed methods and tools cohesively provides decision-makers with both a robust overview and, when needed, a more coordinated and effective detailed support. To utilize its full potential, this approach should now be integrated into decision processes, software and manuals for SPI.

  • 218. Ny, Henrik
    Strategic Life-Cycle Modeling for Sustainable Product Development2006Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Decision makers are challenged by complex sustainability problems within the socio-ecological system. In response, a vast range of sustainability-related methods/tools have been developed, each focusing on certain aspects of this challenge. Without a unifying theory it is, however, unclear how these methods/tools can support strategic progress towards sustainability and how they relate to each other. This need for clarity and structure urged some sustainability pioneers to start develop an overarching framework for strategic sustainable development (SSD), often called “The Natural Step (TNS) framework”, from the NGO that has facilitated its development and application, or the “backcasting from sustainability principles (BSP) framework” from its main operational philosophy. The aim of this thesis is to study if, and in that case how, this framework can aid coordination and further development of various sustainability-related methods/tools, specifically to increase their capacity to support sustainable product development (SPD). Life-cycle assessment (LCA), “templates” for SPD and systems modeling and simulation (SMS) are the methods/tools in focus. A new strategic life-cycle management approach is presented, in which the main sustainability aspects, LCA “impacts”, are identified through socioecological sustainability principles. This creates new opportunities to avoid the reductionism that often follows from traditional system boundaries or from a focus on specific impacts. Ideas of how this approach can inform the studied tools are given. This may eventually lead to a whole integrated toolbox for SPD (a “Design Space”). As part of such a Design Space, a new “template” approach for SPD is developed. A case study of a sustainability assessment of TVs at the Matsushita Electric Group indicates that this approach can create a quick overview of critical sustainability aspects in the early part of the product development process and facilitate communication of this overview between top management, product developers, and other stakeholders. A potential integration between BSP and SMS is also discussed. It is suggested that this should start with BSP to create lists of critical presentday flows and practices, ideas of long term solutions and visions, and a first rough idea about prioritized early investments. After that, SMS should be applied to study the interrelationships between the listed items, in order to create more robust and refined analyses of the problems at hand, possible solutions and investment paths, while constantly coupling back to the sustainability principles and guidelines of the BSP framework. v Decision makers seem to need more of an overview and of simplicity around sustainability issues. A general conclusion is, however, that it is important that this is achieved without a loss of relevant aspects and their interrelations. Over-simplifications might lead to sub-optimized designs and investments paths. Combining the BSP framework with more detailed methods/tools seems to be a promising approach to finding the right balance and to get synergies between various methods/tools.

  • 219.
    Ny, Henrik
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för strategisk hållbar utveckling.
    Sustainability Constraints as System Boundaries. An Approach to Making Life-Cycle Management Strategic.2006Inngår i: Journal of Industrial Ecology, ISSN 1088-1980, E-ISSN 1530-9290, Vol. 10, nr 1-2, s. 61-77Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Sustainable management of materials and products requires continuous evaluation of numerous complex social, ecological, and economic factors. A number of tools and methods are emerging to support this. One of the most rigorous is life-cycle assessment (LCA). But LCAs often lack a sustainability perspective and bring about difficult trade-offs between specificity and depth, on the one hand, and comprehension and applicability, on the other. This article applies a framework for strategic sustainable development (often referred to as The Natural Step (TNS) framework) based on backcasting from basic principles for sustainability. The aim is to foster a new general approach to the management of materials and products, here termed “strategic life-cycle management.” This includes informing the overall analysis with aspects that are relevant to a basic perspective on (1)sustainability, and (2) strategy to arrive at sustainability. The resulting overview is expected to help avoid costly assessments of flows and practices that are not critical from a sustainability and/or strategic perspective and to help identify strategic gaps in knowledge or potential problems that need further assessment. Early experience indicates that the approach can complement some existing tools and concepts by informing them from a sustainability perspective—for example, current product development and LCA tools.

  • 220. Ny, Henrik
    et al.
    Broman, Göran
    MacDonald, Jamie
    Yamamoto, Ryoichi
    Robèrt, Karl-Henrik
    Sustainable Management of Materials Products and Services – an Approach to Strategic LCA2004Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper outlines the need for a more structured and simplified Life Cycle Assessment approach – called Strategic LCA. It builds on a previously published and peer-reviewed methodology using backcasting from basic principles of socio-ecological sustainability. The idea is to simplify, not by excluding parts of the traditionally covered dimensions in this field, but by a new way of setting system boundaries. Rather than applying boundaries related to geographic regions, or fields of expertise, or particular impacts, all issues found to be relevant as regards achieving sustainability are taken into account. To that end, we use four previously published generic principles of socio-ecological sustainability for the scrutinizing of materials, products and services.

  • 221.
    Ny, Henrik
    et al.
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för strategisk hållbar utveckling.
    Hallstedt, Sophie
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för strategisk hållbar utveckling.
    Ericson, Åsa
    A Strategic Approach for Sustainable Product Service System Development2013Inngår i: Proceedings of the 22nd CIRP Design Conference 2012, Conference on Assembly Technologies & Systems (CIRP), 2013, s. 427-436Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Product-Service Systems (PSS) have been justified by a desire to find sustainable solutions that go beyond contemporary approaches. The characteristics of PSS of-ferings are to link goods and services in development and to provide systemic per-formance-based solutions to the customers. This paper investigates how estab-lished strategic product development tools for socio-ecological sustainability could be adapted for PSS development. An approach is suggested for how to apply these tools in early PSS development phases.

  • 222. Ny, Henrik
    et al.
    Hallstedt, Sophie
    Robèrt, Karl-Henrik
    Broman, Göran
    Introducing Templates for Sustainable Product Development: A Case Study of Televisions at the Matsushita Electric Group2008Inngår i: Journal of Industrial Ecology, ISSN 1088-1980, E-ISSN 1530-9290, Vol. 12, nr 4, s. 600-623Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We have previously developed a method for sustainable product development (MSPD) based on backcasting from basic sustainability principles. The MSPD informs investigations of product-related social and ecological sustainability aspects throughout a concurrent engineering product development process.We here introduce “templates” for sustainable product development (TSPDs) as a complement. The idea is to help product development teams to arrive faster and more easily at an overview of the major sustainability challenges and opportunities of a product category in the early development phases. The idea is also to inform creative communication between top management, stakeholders, and product developers. We present this approach through an evaluation case study, in which the TSPDs were used for a sustainability assessment of televisions (TVs) at the Matsushita Electric Group.We study whether the TSPD approach has the ability to (1) help shift focus from gradual improvements of a selection of aspects in relation to past environmental performance of a product category to a focus on the remaining gap to a sustainable situation, (2) facilitate consensus among organizational levels about major sustainability challenges and potential solutions for a product category, and (3) facilitate continued dialogue with external sustainability experts, identifying improvements that are relevant for strategic sustainable development. Our findings indicate that the TSPD approach captures overall sustainability aspects of the life cycle of product categories and that it has the above abilities.

  • 223. Ny, Henrik
    et al.
    Haraldsson, Hördur V.
    Sverdrup, Harald U.
    Robert, Karl-Henrik
    Systems Dynamic Modeling within Sustainability Constraints2005Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this study we are asking ourselves whether ■Systems Dynamic Modelling■ can be combined with ■Backcasting from Sustainability Principles■ to support strategic planning towards sustainability. From the perspective of a ■Backcasting Practitioner■, ■Systems Dynamic Modelling■ is a set of tools that help gaining insight into the detailed functioning of a given system, but lacks the ability to support strategic planning towards sustainability ■ unless complemented with a satisfactory goal definition. ■Backcasting from Sustainability Principles■, in the eyes of a ■Systems Modeller■, is the planning step of a learning loop that also includes action implementation and follow-up. Since no dynamic modelling takes place this methodology typically produces laundry lists of isolated problems and solutions, thereby missing potentially important feedback loops, delays, hidden problems and suitable intervention points in the system.

  • 224. Ny, Henrik
    et al.
    MacDonald, Jamie
    Broman, Göran
    Robèrt, Karl-Henrik
    Sustainability Constraints as System Boundaries: Introductory Steps Toward Stategic Life-Cycle Management2008Inngår i: Web-based green products life-cycle management systems: reverse supply-chain utilization / [ed] Wang, Hsiao-Fan, Hershey, USA: IGI Global: Information Science Reference , 2008Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Sustainable management of materials and products requires continuous evaluation of numerous complex social, ecological, and economic factors. Many tools and methods are emerging to support this. One of the most rigorous is life-cycle assessment (LCA). But LCAs often lack a sustainability perspective and bring about difficult trade-offs between specificity and depth, on the one hand, and comprehension and applicability, on the other. This article applies a framework for strategic sustainable development to foster a new general approach to the management of materials and products, here termed “strategic life-cycle management.” This includes informing the overall analysis with aspects that are relevant to a basic perspective on (1) sustainability, and (2) strategy to arrive at sustainability. Early experiences indicate that the resulting overview could help avoiding costly assessments of flows and practices that are not critical from a sustainability and/or strategic perspective and help identifying strategic knowledge gaps that need further assessment.

  • 225. Ola, Isaksson
    et al.
    Tobias, Larsson
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Michael, Kokkolaras
    Marco, Bertoni
    Simulation Driven Design for Product-Service Systems2013Inngår i: The Philosopher's Stone for Sustainability / [ed] Yoshiki, Shimomura; Koji, Kimita, Berlin, Heidelberg: Springer , 2013, s. 465-470Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Total Offers, Functional Products, and Integrated Product Service Engineering reflect a shift toward service offers from manufacturing industry captured within the term Product-Service Systems (PSS). Manufacturing companies have traditionally focused design and development activities on realizing technical and engineered aspects of physical artifacts, while PSS include deeper understanding of customers’ expectation, needs and perceived value, hence calling for modelling of additional aspects. The change in early design processes and the effects on virtual modelling of product properties are discussed in this paper through aerospace industry examples to clarify ‘parameters of change’, giving suggestions for a simulation driven design (SDD) approach.

  • 226. Olsson, Ulrika
    et al.
    Haller, Kristian
    Östholm, Stefan
    Dynamic Automated Measurement on Light Weight Test Panels1999Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper describes an automated approach to modal testing utilizing a robot control to position a Laser Doppler Vibrometer (LDV) beam. The LDV measures the velocity response of test panels to a broad band force excitation. The implementation of the laser beam approach involves moving the beam once for each member of the velocity-force set. It is critical that the beam is positioned precisely, and the measurement set is correctly correlated to the specimen geometry. A programmed robotic system was used for the laser positioning and for keeping the measurement set correctly identified with respect to the specimen geometry. The result clearly shows the possibility to automate time consuming modal measurement of lightweight structures by utilizing a robot to control a LDV.

  • 227.
    Oscar, Petersson
    et al.
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    John, Heideman
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    Framtagning av en ergonomisk monteringsarm till kontrollpaneler med en modulär produktutvecklingsprocess2017Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Norden Machinery AB i Kalmar är idag en ledande leverantör inom högpresterande tubfyllingssystem. Dessa är mestadels automatiska, men när det gäller förpackning finns det några arbetsmoment som utförs manuellt. Detta gör att de ergonomiska aspekterna kring dessa arbetsmoment måste prioriteras högt. I den nuvarande situationen utgör panelarmen som håller fast maskinens kontrollpanel ett ergonomiskt problem då den varken går att höja eller sänka. Syftet med projektet är att tillsammans med Norden utveckla en ergonomisk och användarvänlig lösning gällande panelarmen vid tubfyllningsmaskinerna. Frågeställningen behandlar hur detta görs genom att integrera design för ergonomi, flexibilitet och moduläritet i designprocessen. För att uppfylla syftet och frågeställningen med arbetet användes den grundläggande produktutvecklingsprocessen som Ulrich och Eppinger (2012) har tagit fram. Processen utgår från en förstudie där kraven på produkten sammanställs i en kravspecifikation och att designproblemet delas upp i mindre delproblem. Med detta som grund genereras koncept som därefter utvärderas mot kravspecifikationen vilket slutligen resulterar i att ett koncept väljs ut för vidareutveckling. Till dessa steg har teori och verktyg kring ergonomi, flexibilitet och moduläritet implementerats. Den slutgiltiga lösningen utgörs av modulära komponenter och är betydligt mer ergonomisk och användarvänlig än Nordens nuvarande konstruktion. Lyftanordningen består av en parallellogram och en gasfjäder omslutna av ett par balkar. Detta ger den lyftfunktion som krävs för att konstruktionen ska kunna hålla skärmen på plats och dessutom erbjuda höj- och sänkbarhet. Båda fästena gjordes i princip identiska och baserades på fästena hos Nordens nuvarande lösning. På så sätt behöver inga nya fästpunkter konstrueras och kostnaden kan hållas nere. Överlag förväntas konstruktionen uppnå de förväntningar och mål som både vi och Norden har. Den ergonomiska designaspekten passade bäst in vid förstudien, vilket beror mycket på att teorin kring ergonomi har sin grund i de regler, riktlinjer och mål som berör slutprodukten. Moduläriteten bidrog till att mer detaljerade koncept kunde skapas tack vare problem-uppdelningen. Flexibiliteten var inte fullt lika användbar men gav bra understöd till moduläriteten under processens gång. Huvudsaken är att vid en implementering likt denna ta hänsyn till eventuella kompromisser som kan behöva göras, och att alltid ha slutmålet med projektet i åtanke.

  • 228. Ostrovsky, L. A.
    et al.
    Rudenko, Oleg
    What Problems of Nonlinear Acoustics Seem to be Important and Interesting Today2008Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The purpose of this presentation is to briefly outline the progress and achievements that have occurred in some areas of nonlinear acoustics during recent years. © 2008 American Institute of Physics.

  • 229.
    Panarotto, Massimo
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Capturing Value in Conceptual PSS Design: Perspectives from the Automotive Supply Chain2013Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Manufacturing companies have traditionally focused their design and development activities on realizing technical and engineered aspects of physical artifacts based on performance requirements. The ever-changing business climate, with its increased pace during the past decades, has forced industries to continuously innovate their approach toward the development of new products. Pressured also by global competition, manufacturing companies need to reconsider the traditional concept of realizing value via goods production, and shift towards realizing value through product-service combinations. Companies have begun to recognize that gaining competitive advantage and expanding market shares is not achievable purely through continuous technical improvements. Rather, it is necessary to develop a closer relationship to the customer to gain a deeper understanding of expectations, needs, and perceived value. From a development perspective, the overarching problem within complex systems such as those in which cars, aircraft, and excavators are manufactured, or healthcare is provided, is that the focus on customer value is likely to become blurred since it is difficult to understand the impact a change in any single component in the overall system has on value, and to determine a new function’s impact on future scenarios. The main goals of this thesis are to provide an understanding of key challenges when considering the value different design alternatives provide in the conceptual phases of product development taking the automotive industry as case study, and to explore how to support a multi-disciplinary design team in making value-conscious decisions when dealing with new product-service offerings. The research approach has involved data collection through participation in, and facilitation of, product-service design workshops in the automotive industry. Also, it has involved follow-up meetings and interviews, as well as a review of literature on state-of-the-art methods in early conceptual design phases, which describes the advantages and disadvantages of the different frameworks. The primary finding of the study is that determination of the impact of different PSS design options on customer value becomes more challenging since new elements are introduced (e.g., new business models and services). The design team requires more holistic competences in order to more fully understand changing contexts; and new methods and tools are needed in order to establish a base to define, discuss and assess what “uncontested customer value” is, and link it to the different product-service elements of the system. Secondly, this thesis proposes a conceptual approach for value simulation and assessment of different design options, where the iterative use of personas and scenario generation is combined with value modeling and computer-based simulation techniques, enabling a quick “what-if” analysis of the various options, facilitating the identification of promising combinations of product and service elements that provide higher customer value.

  • 230.
    Panarotto, Massimo
    et al.
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Larsson, Tobias
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Towards Value Driven Simulation of Product-Service Systems: A Conceptual Scenario2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The paper discussed potentials and existing challenges of considering Value when designing a Product-Service System offering. The main problem has been identified on having new methods and tools that can help designers to consider every design option from a value perspective (possibly based on a longer timespan). Nowadays mainly revenue, costs and technical risks analysis are taken into consideration and boiled down into monetary terms in a rather short period. This often caused the “killing” of more radical ideas (that could potentially bring more benefits if seen in a longer time perspective) at the various decision gates during the project. So at the end, everybody talks about value, but actually money is what people look at in the end. The paper discussed how a Value simulation approach can provide benefits in terms of compared different design solutions from a Value perspective. With such an approach it is possible to take into consideration the value of aspects like intangibles perceived by the customer (provide the best customer experience as possible) or knowledge gained by the company during the business. An example has been presented in order to discuss how Value simulation can be effectively a strength when dealing with the wider design space that the PSS development implies. Another main benefit is that such a tool will enable engineers to have at least “reasoning” in order to sponsor more radical concepts. Thirdly, the tool can enable optimization and increase innovation, since the team can look at why the model has low value in a certain lever, and starting to brainstorm possible solutions of how to increase it. However, the approach is still in its infancy and future work needs to be done. First of all, the weighting phase is crucial since it will profoundly affect the model. Further research will focus how the design team can place define weights in a qualitative but effective way, in order to take the major benefits from a “lightweight” qualitative approach and the simulation based on mathematical equations. Secondly, work has to address how intangibles and knowledge can affect monetary parameters, such as the price of the offerings or costs (making the intangibles tangible, so to say). This will require further research, but it has been seen as a great opportunity of making a step further in the topic, since the uncovered areas realted intangibles and knowledge are still many.

  • 231.
    Panarotto, Massimo
    et al.
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Larsson, Tobias
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Larsson, Andreas
    Enhancing supply chain collaboration in automotive industry by value driven simulation2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a computer-based approach for conceptual design that aims to enhance collaborative supply chain development in the automotive sector when dealing with product-service development or radical innovations. The focus of the research has been to design a simulation approach that will enable designers and managers to simulate and evaluate the value of different design options for the different stakeholders involved in the development process and to have insights about the implications between business model innovation and the engineered aspects of the solutions early in the conceptual phase. The approach is presented using a case study within the current project, after following a team responsible for the car cockpit. Four possible scenario have been simulated and evaluated using a commercial simulation software. The main advantage of the proposed approach is to enhance the awareness among designers and managers of the value of different design options, and allow them to explore further how business and design aspects profoundly affect each other, in order to support early decision-making in the design process.

  • 232. Pilthammar, Johan
    et al.
    Sigvant, Mats
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    Hansson, Mårten
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    Pálsson, Einar
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    Rutgersson, Wilhelm
    Cascade Control AB, SWE.
    Characterizing the Elastic Behaviour of a Press Table throughTopology Optimization2017Inngår i: Journal of Physics: Conference Series / [ed] Volk W., Institute of Physics Publishing (IOPP), 2017, Vol. 896, artikkel-id 012101Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Sheet metal forming in the car industry is a highly competitive area. The use ofdigital techniques and numerical methods are therefore of high interest for reduced costs andlead times. One method for reducing the try-out phase is virtual rework of die surfaces. Thevirtual rework is based on Finite Element (FE) simulations and can reduce and support manualrework. The elastic behaviour of dies and presses must be represented in a reliable way in FEmodelsto be able to perform virtual rework. CAD-models exists for nearly all dies today, butnot for press lines. A full geometrical representation of presses will also yield very large FEmodels.This paper will discuss and demonstrate a strategy for measuring and characterizing apress table for inclusion in FE-models. The measurements of the elastic press deformations iscarried out with force transducers and an ARAMIS 3D optical measurement system. The presstable is then inverse modelled by topology optimization using the recorded results as boundaryconditions. Finally, the press table is coupled with a FE-model of a die to demonstrate itsinfluence on the deformations. This indicates the importance of having a reliable representationof the press deformations during virtual rework.

  • 233.
    Pilthammar, Johan
    et al.
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    Wall, Johan
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    Sigvant, Mats
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    Framework for Simulation-Driven Design of Stamping Dies Considering Elastic Die and Press Deformations2017Inngår i: PROCEEDINGS OF THE 20TH INTERNATIONAL ESAFORM CONFERENCE ON MATERIAL FORMING (ESAFORM 2017) / [ed] Brabazon D.,Ul Ahad I.,Naher S., American Institute of Physics (AIP), 2017, Vol. 1896, artikkel-id 010001Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Sheet metal forming (SMF) simulations are used extensively throughout the development phase of industrialstamping dies. In these SMF simulations, the die and press are normally considered as rigid. Previous research has howevershown that elastic deformation in these parts has a significant negative impact on process performance. This paperdemonstrates methods for counteracting these negative effects, with a high potential for improved production support anda reduced lead time through a shorter try-out process. A structural finite element model (FE-model) of a simplified die isstudied. To account for elastic deformation, the blankholder surfaces are first virtually reworked by adjusting the nodalpositions on the die surfaces attaining a pressure distribution in accordance to the design phase SMF simulations with rigidsurfaces. The elastic FE-model with reworked surfaces then represents a stamping die in running production. The die isnow assumed to be exposed to changed process conditions giving an undesired blankholder pressure distribution. Thechanged process conditions could for example be due to a change of press line. An optimization routine is applied tocompensate the negative effects of the new process conditions. The optimization routine uses the contact forces acting onthe shims of the spacer blocks and cushion pins as optimization variables. A flexible simulation environment usingMATLAB and ABAQUS is used. ABAQUS is executed from MATLAB and the results are automatically read back intoMATLAB. The suggested optimization procedure reaches a pressure distribution very similar to the initial distributionassumed to be the optimum, and thereby verifying the method. Further research is needed for a method to transform thecalculated forces in the optimization routine back to shims thicknesses. Furthermore, the optimization time is relativelylong and needs to be reduced in the future for the method to reach its full potential.

  • 234.
    Punnam, Pradeep Reddy
    et al.
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    Dundeti, Chitendar Reddy
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    A Finite Element Analysis of Crack Propagation in Interface of Aluminium Foil - LDPE Laminate During Fixed Arm Peel Test.2017Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis deals with numerical simulation of a peel test with an Aluminium foil and Low Density Poly-Ethylene (LDPE) laminate. This work investigates the effects of the substrate thickness and studies the influences of interfacial strength and fracture energy of the cohesive zone between the Aluminium and LDPE. This study evaluates the proper guidelines for defining cohesive properties. A numerical cohesive zone model was created in ABAQUS. Continuum tensile tests were performed to extract LDPE material properties. The aluminium properties were found in literature. After acquiring material parameters, the simulation continued with studying the effects of changing interfacial strength, geometric parameters and fracture energy. The results were obtained in the form of root rotations and the force displacement response was studied carefully. It was validated by comparison to the traction separation curve.

  • 235.
    Reheman, Wureguli
    et al.
    Lunds Universitet, LTH, SWE.
    Ståhle, Per
    Lunds universitet, SWE.
    Interface instability of growing hydrides2016Inngår i: Procedia Structural Integrity / [ed] Francesco Iacoviello, Luca Susmel, Donato Firrao, Giuseppe Ferro, Elsevier, 2016, Vol. 2, s. 589-596s. 589-596Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Formation of metal hydrides is a serious complication that occur when hydride forming metals such as zirconium, niobium, vanadium and magnesium are exposed to long term hydrogen environment. The main concern is that the hydride, as being a brittle material, has very poor fracture mechanical properties. Formation of hydride is associated with transportation of hydrogen along the gradients of increasing hydrostatic stress, which leads to crack tips and other stress concentrators, where it forms the hydride. In the present study the thermodynamics of the evolving hydrides is studied. The process is driven by the release of free strain, chemical, and gradient energies. A phase field model is used to capture the driving forces that the release of the free energy causes. The study gives the conditions that lead to hydride advancement versus retreat and under which conditions the metal-hydride interface becomes unstable and develops a waviness. The spatial frequency spectrum leading to instability is found to depend on the ratio of the elastic strain energy density and parameters related to the interface energy.

  • 236.
    Reheman, Wureguli
    et al.
    Lunds universitet, LTH, SWE.
    Ståhle, Per
    Lunds universitet, SWE.
    Durgé, Ellias
    Lund University, LTH, SWE.
    Singh, Ram N.
    Bhabha Atomic Research Centre, Mumbai, India.
    Phase Field Modelling of Formation and Fracture of Expanding Precipitates2017Inngår i: Procedia Structural Integrity / [ed] Francesco Iacoviello, Luca Susmel, Donato Firrao, Giuseppe Ferro, Elsevier, 2017, Vol. 3, s. 477-483s. 477-483Konferansepaper (Fagfellevurdert)
    Abstract [en]

    It is a common belief that embedded expanding inclusions are subjected to an internal homogeneous compressive hydrostatic stress. Still, cracks that appear in precipitates that occupy a larger volume than the original material, are frequently observed. The appearance of cracks has since long been regarded as a paradox. In the present study it is shown that matrix materials that increases its volume even several percent during the precipitation process develop a tensile hydrostatic stress in the centre of the precipitate. This is the result of a complicated mechanical-chemical phase transformation process. The process is here studied using a Landau phase feld model. Before the material is transformed and incorporated in a precipitate it undergoes stretching beyond the elastic strain limit because of the presence of already expanded material. During the phase transformation, the accompanying volumetric expansion cannot be fully accommodated which instead creates an internal compressive stress and adds tension in the surrounding material. As the growth of the precipitate proceeds, a region with increasing tensile stress develops in the interior of the precipitate. This is suggested to be the most probable cause of the observed cracks. First the mechanics that lead to the tension is computed. The infuence of elastic-plastic properties is studied both for cases both with and without cracks. The growth history from microscopic to macroscopic precipitates is followed and the result is compared with observations of so called hydride blisters that are formed on surfaces of zirconium alloys in the presence of hydrogen. A common practical situation is when the zirconium is in contact with an object of lower temperature. Then the cooled spot attracts hydrogen that make the zirconium transform to a metal hydride with the shape of a blister. The simulations predicts a final size and position of the growing crack that compares well with the experimental observations.

  • 237. Rudenko, Oleg
    Giant nonlinearities in structurally inhomogeneous media and the fundamentals of nonlinear acoustic diagnostic techniques2006Inngår i: Physics Uspekhi, ISSN 1063-7869, E-ISSN 1468-4780, Vol. 49, nr 1, s. 69-87Artikkel, forskningsoversikt (Fagfellevurdert)
  • 238.
    Rudenko, Oleg
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    Nonlinear integro-differential models for intense waves in media like biological tissues and geostructures with complex internal relaxation-type dynamics2014Inngår i: Acoustical Physics, ISSN 1063-7710, E-ISSN 1562-6865, Vol. 60, nr 4, s. 398-404Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The paper discusses a universal scheme for constructing nonlinear integro-differential models to describe intense waves in media with a complex internal relaxation-type dynamics. Examples of such media are presented. Various forms of kernels are described. Situations are shown in which the models can be simplified by reducing them to differential or differential-difference equations with partial derivatives. Integral relations for the linear momentum and energy transferred by the wave are obtained. Exact solutions are found. The mapping method is used to obtain approximate solutions and analyze them in the form of difference relations.

  • 239. Rudenko, Oleg
    Nonlinear Waves: some biomedical applications2007Inngår i: Physics Uspekhi, ISSN 1063-7869, E-ISSN 1468-4780, Vol. 50, nr 4Artikkel i tidsskrift (Fagfellevurdert)
  • 240. Rudenko, Oleg
    The 40th Anniversary of the Khokhlov-Zabolotskaya Equation2010Inngår i: Acoustical Physics, ISSN 1063-7710, E-ISSN 1562-6865, Vol. 56, nr 4, s. 452-462Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The 40th anniversary of the Khokhlo-Zabolotskaya equation was marked by a special session of the 158th Meeting of the Acoustical Society of America (October 2009, San Antonio, Texas, United States). A response on the part of Acoustical Physics to this date is also quite appropriate, all the more so because Russian scientists were the main players involved in formulating and using this equation during the period of time between the middle 1960s and middle 1980s. In this article, the author—a participant and witness of those events—presents his view of the dramatic history of the formulation of this equation and related models in the context of earlier and independent work in aerodynamics and nonlinear wave theory. The main problems and physical phenomena described by these mathematical models are briefly considered.

  • 241. Rudenko, Oleg
    V.A.Robsman: Nonlinear Testing and Building Industry2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This talk is devoted to the memory of outstanding scientist and engineer Vadim A. Robsman who died in January 2005. Dr.Robsman was the Honored Builder of Russia. He developed and applied new methods of nondestructive testing of buildings, bridges, power plants and other building units. At the same time, he published works on fundamental problems of acoustics and nonlinear dynamics. In particular, he suggested a new equation of the 4-th order continuing the series of basic equations of nonlinear wave theory (Burgers Eq.: 2-nd order, Korteveg - de Vries Eq.: 3-rd order) and found exact solutions for high-intensity waves in scattering media. © 2006 American Institute of Physics.

  • 242. Rudenko, Oleg
    et al.
    Crocker, Malcolm
    Nonlinear Acoustics2006Inngår i: Handbook of Noise and, New York: Wiley and Sons , 2006, s. 159-168Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 243. Rudenko, Oleg
    et al.
    Gurbatov, Sergey
    Hedberg, Claes
    Nonlinear Acoustics Through Problems and Examples2010Bok (Annet vitenskapelig)
    Abstract [en]

    The fundamentals of nonlinear acoustics are presented in form of problems followed by solutions, explanations and answers. As distinct from existing textbooks, this book of problems not only helps the reader to become familiar with nonlinear wave processes and the methods of their description, but contributes to mastering calculation procedures and obtaining numerical estimates of the most significant parameters. Thereby, skills are acquired which are indispensable for carrying out original scientific research. This book can be useful to undergraduate and postgraduate students and researchers working in the field of nonlinear wave physics and acoustics.

  • 244. Rudenko, Oleg
    et al.
    Gurbatov, Sergey
    Hedberg, Claes
    Nonlinear Acoustics through Problems and Examples (in Russian)2006Bok (Annet vitenskapelig)
  • 245.
    Rudenko, Oleg
    et al.
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Gurbatov, S.N.
    Demin, I.Yu.
    Absorption of intense regular and noise waves in relaxing media2014Inngår i: Acoustical Physics, ISSN 1063-7710, E-ISSN 1562-6865, Vol. 60, nr 5, s. 499-505Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An integro-differential equation is written down that contains terms responsible for nonlinear absorption, visco-heat-conducting dissipation, and relaxation processes in a medium. A general integral expression is obtained for calculating energy losses of the wave with arbitrary characteristics-intensity, profile (frequency spectrum), and kernel describing the internal dynamics of the medium. It is shown that for weak waves, the general integral leads to well-known results of a linear approximation. Profiles of stationary solutions are constructed both for an exponential relaxation kernel and for other types of kernels. Energy losses at the front of week shock waves are calculated. General integral formulas are obtained for energy losses of intense noise, which are determined by the form of the kernel, the structure of the noise correlation function, and the mean square of the derivative of realization of a random process

  • 246. Rudenko, Oleg
    et al.
    Hedberg, Claes
    Nonlinear Dynamics of Grains in a Liquid-Saturated Soil2003Inngår i: Nonlinear dynamics, ISSN 0924-090X, E-ISSN 1573-269X, Vol. 35, nr 2, s. 187-200Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new kind of nonlinearity of inertial type caused by accelerated motion of interacting particles is described. The model deals with an ensemble of grains immersed into a vibrating fluid. First, the nonlinear vibration of two connected grains is studied. The temporal behaviours of displacement and velocity, as well as spectrum of vibration, are analysed. Numerical simulations are performed. Then an infinite chain of grains is considered and the corresponding differential-difference equation is derived. For the continuum limit the inhomogeneous nonlinear wave equation is solved and temporal profiles are calculated. A new resonant phenomenon is described and the resonant curves are constructed.

  • 247. Rudenko, Oleg
    et al.
    Hedberg, Claes
    Nonlinear vibrations and waves in a granular and liquid-saturated medium2004Inngår i: Acoustics of Inhomogeneous Media, Russian Acoustical Society , 2004, s. 1-15Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 248.
    Rudenko, Oleg
    et al.
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    Hedberg, Claes
    Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, Avdelningen för maskinteknik.
    The phenomenon of self-trapping of a strongly nonlinear wave.2014Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 135, nr 4Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Self means here an effect of a wave on itself. Several self-action phenomena are known in nonlinear wave physics. Among them are self-focusing of beams self-compression of light pulses self-channeling self-reflection (or self-splitting) waves with shock fronts self-induced transparency and self-modulation. These phenomena are known for weakly nonlinear waves of different physical origin. Our presentation at ASA meeting in Montreal [POMA 19 045080 (2013)] was devoted to strongly nonlinear waves having no transition to the linear limit at infinitesimally small amplitudes. Such waves can demonstrate particle-like properties. Self-trapping consists of the arrest of wave propagation and in the formation of a localized state. In particular the model generalizing the Heisenberg' ordinary differential equation to spatially distributed systems predicts periodic oscillations but no traveling waves. Different models for strongly nonlinear waves will be considered and some unusual phenomena will be discussed. Preliminary results were published in Ac. Phys. 59 584 (2013) and Physics-Uspekhi (Adv. Phys. Sci.) 183 683 (2013). [This work was supported by the Megagrant No.11.G34.31.066 (Russia) and the KK Foundation (Sweden).

  • 249. Rudenko, Oleg
    et al.
    Hedberg, Claes
    Enflo, Bengt
    Finite-Amplitude Standing Acoustic Waves in a Cubically Nonlinear Medium2007Inngår i: Acoustical Physics, ISSN 1063-7710, E-ISSN 1562-6865, Vol. 53, nr 4, s. 455-464Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The behavior of the wave field in a resonator containing a cubically nonlinear medium is studied. The field is constructed as a linear superposition of two counter-propagating and strongly distorted waves. As distinct from a quadratic nonlinear medium the waves traveling in opposite directions are connected through their averaged (over the period) intensities. Both free and forced standing waves are studied. Profiles of discontinuous vibrations containing shock fronts of both compression and rarefaction are constructed. Resonant curves depicting the dependence of mean intensity on the difference between the frequency of vibration of the boundary and the natural frequency of one of the resonator’s mode are calculated. The structure of temporal profiles of strongly distorted forced waves is analyzed. It is shown, that shocks can appear only if the difference between the mean intensity and the discrepancy takes on definite negative values. The discontinuities are studied as jumps between the different solutions of a nonlinear integro-differential equation degenerating at weak dissipation to a third order algebraic equation with an undetermined coefficient. The dependence of the intensity of shocked vibrations on the frequency of vibration of the boundary is found. Nonlinear saturation is shown to appear: the intensity of wave field inside the resonator does not depend on the amplitude of boundary vibration when the amplitude is large. If the amplitude tends to infinity, the intensity tends to its limiting value determined by the nonlinear absorption at shock fronts. This maximum can be reached by smooth increase in frequency above the linear resonance. A hysteresis area and bistability appears, in analogy with the nonlinear resonance phenomena in localized vibration systems described by ordinary differential equations.

  • 250. Rudenko, Oleg
    et al.
    Hedberg, Claes
    Enflo, Bengt
    Nonlinear standing waves in a layer excited by periodic motion of its boundary2001Inngår i: Acoustical Physics, ISSN 1063-7710, E-ISSN 1562-6865, Vol. 47, nr 4, s. 452-460Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new analytical approach is developed for the description of standing waves caused by arbitrary periodic vibration of a boundary. The approach is based on the nonlinear evolution equation written for an auxiliary function. This equation offers the possibility to study not only the steady-state acoustic field, but also its evolution in time. One can take into account the dissipative properties of the medium and the difference between one of the resonant frequencies and the fundamental frequency of the driving motion of the wall. An exact non-steady-state solution is derived corresponding to the sawtooth-like periodic vibration of the boundary. The maximal amplitude? values of the particle velocity and the energy of standing waves are calculated. The temporal profiles of standing waves at different points of the layer are presented. A new possibility of pumping a high acoustic energy into a resonator is indicated for the case of a special type of wall motion having the form of an ?inverse saw?. Theoretically, such a vibration leads to an ? explosive instability? and an unlimited growth of the standing wave. For a harmonic excitation, the exact non-steady-state solution is derived as well. The standing wave profiles are described by Mathieu functions, and the energy characteristics by their eigen-values.

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