Fracture mechanics theoretical modelling and Finite Element Method analysis of a pre-cracked 3-Point Bending Specimen (3PBS) have been conducted in this paper. Using the equivalent system of the specimen, fracture mechanical characteristics have been analyzed and the theoretical Dynamic Stress Intensity Factor (DSIF) is obtained later and used together with the Pairs theorem to analyze the fatigue life time of the specimen. Based on the simulations from ABAQUS, dynamic characteristics of the pre-cracked 3PBS are obtained and verified. The results are further analyzed and discussed with special concern on fracture mechanics characteristics of the material and will provide a guideline for further research and practical design