Ultra-thin Strip Rolling Numerical Simulation Based On The Crystal Plasticity Theory

Ultra-thin strip,which is different from traditional strip,has a very wide application in the field of aerospace,medical equipment and other high-tech area.And this put forward high request for ultra-thin strip rolling production,especially the plan of rolling process and the control of strip surface need to keep a high precision.At present,the macro inquiry of ultra-thin strip is more deeply at home and abroad,but the mesoscopic research are relatively few.Here mainly through the finite element software to analyze the changes of ultra-thin strip rolling on the mesoscopic scale.The computer simulation of strip rolling on the mesoscopic scale,firstly needs to create a random grain model in ABAQUS.This subject adopts the Voronoi polygon algorithm by MATLAB software to generate 2D and 3D random grain structure and models in ABAQUS by imported data.Then,based on the crystal plasticity theory,the polycrystal constitutive model adapted to the mesoscopic scale is built by using the user material subroutine in ABAQUS.Through simulating the single crystal aggregation uniaxial tensile,we can analyze the tensile deformation results.And through the geometry optimizing for the grain boundary model,it can make the grain model to a ideal deformation effect.Based on the first principles,the crystal lattice constant can be calculated based on the empirical formula,and the elastic constants of each phase crystal of GCr15 have been simulated by MS software.Through calling the elastic constants of different crystals and related parameters in UMAT,the material property of different quenching time has been simulated and the optimal property material is chosen to serve as strip material of static rolling.Ultra-thin strip static rolling simulation is built.By simulating 2D strip rolling process,the stress and strain characteristics of the different position grain in rolling model have been comparatively analyzed,and the grain orientation and grain size on the influence of the rolling process have been explored.It is concluded that the grain orientation tends to the rolling direction is beneficial to the rolling effect,the small size grain can reduce stress concentration distribution of rolling strip after rolling.This canprovide certain reference for practical production.At the same time,by simulating 3D strip rolling process,the stress and strain change characteristics have been analyzed when the rolling process is at initial,intermediate and finish time.And the mesoscopic rolling process is clearly showed.Then,through intercepting strip cross section after rolling,the stress and strain nephogram in the cross section is observed and the stress and strain change characteristics are analyzed.