Effect of Strain Rate on Material Properties of Carbody Parts Based on HyperMesh
In the process of body collision,the deformation strain rate of parts at different positions is quite different,which has an important impact on the properties of materials.HC300LA,which was a common material for automobile structural parts,was selected as the research object to obtain the high-speed tensile properties of the material under different strain rates.Through the observation of fracture morphology and microstructure changes,the plastic deformation and fracture characteristics of the ma-terial under different strain rates were analyzed and studied,and the influence law of strain rate was obtained.The relationship between energy absorption,dimple size and strain rate was obtained.The constitutive equation of dynamic mechanical properties of materials was established based on Johnson-cook model.The tensile specimen simulation analysis model was built based on HyperMesh.By applying displacement,the force displacement curve of the whole process was obtained and compared with the test results,so as to verify the constitutive model related to material strain rate.The results show that the material has a certain strain rate sensitivity.With the increase of strain rate,its strength and elongation increase.The fracture energy absorption capacity and fracture dimples of the material become larger and deeper,and the distribution of dimples is denser.For the material constitutive model considering the influence of strain rate,the maximum force and maximum displacement of tensile process simulation anal-ysis are basically consistent with the test results,the error is controlled within 4%,and the change trend of force displacement is consistent.The results show that the effect of strain rate on the material cannot be ignored in the collision analysis.At the same time,it shows that the above analysis model is reliable and provides an important reference for this kind of research.
CarbodySpare PartsStrain RateMechanical PropertiesConstitutive Model
NETL
NSTL
万方数据
