Finite Element Simulation Of Dynamic Deformation Behavior Of Medium Manganese TRIP Steel

In recent years,people have gradually paid attention to the weight reduction and safety issues of automobile structures,and medium manganese TRIP steel with good comprehensive mechanical properties is an ideal candidate material for automobile structures.The deformation behavior of this steel under dynamic and quasi-static conditions is very different,which is reflected in the locality of material deformation,adiabatic temperature rise,strong shock wave effects and changes in fracture modes.But so far,most of the researches on the manganese TRIP automotive steel have been quasi-static deformation behavior.Even if the dynamic deformation behavior is studied,it is simply realized by comparing the structural changes before deformation and after breaking.The study of the structural changes and deformation behavior during dynamic deformation cannot be controlled experimentally due to the rapid deformation rate.Therefore,new technologies are needed to further study the stress-strain behavior of medium manganese TRIP steel during dynamic deformation.With the development of computer technology,finite element simulation technology is gradually applied to various fields.Among the many simulation software,ABAQUS is recognized as one of the most comprehensive finite element simulation software in the industry.Therefore,this paper uses ABAQUS to simulate the martensitic transformation and stress-strain distribution of the manganese TRIP steel during dynamic deformation.In this paper,the quasi-static and dynamic mechanical properties of TRIP steel with medium manganese were studied by experiment and simulation under the support of NSFC project(51574077).According to the quasi-static and dynamic tensile tests,the calculation model of the experimental steel was built and the martensitic transformation equation subroutine was compiled.The trip effect and stress-strain distribution of the medium manganese TRIP Steel under different deformation conditions were simulated in ABAQUS finite element software.The main research contents and results are as follows:(1)The quasi-static and dynamic mechanical properties of medium manganese TRIP steel were studied,and the influence of strain rate on the deformation behavior of experimental steel was analyzed.The results showed that the yield strength,tensile strength and elongation of experimental steel increased with the increase of strain rate of 10 s-1 and 200 s-1.(2)Considering the effect of "adiabatic temperature rise",the Johnson-cook constitutive equation suitable for medium manganese TRIP steel under high-speed tensile condition is established:?=(714+1416?0.97)[1+0.0051n(?/?0)](1-0.45?).The equation can accurately describe the mechanical properties of TRIP steel.(3)Combining the Johnson-Cook constitutive equation with the martensitic transformation,a subroutine for the martensitic transformation equation was written,and a finite element model based on the microstructure was established.The model can simulate the martensitic transformation and stress-strain of experimental steel under different deformation conditions more accurately in the finite element software ABAQUS.