基于ABAQUS子程序VUMAT二次开发平台,将位错和孪晶的演化过程引入晶体塑性有限元方法(crystal plastic finite element method,CPFEM)中,实现了多晶塑性材料力学行为的有限元模拟,并通过试验和模拟结果的对比,验证了所提出方法和二次开...基于ABAQUS子程序VUMAT二次开发平台,将位错和孪晶的演化过程引入晶体塑性有限元方法(crystal plastic finite element method,CPFEM)中,实现了多晶塑性材料力学行为的有限元模拟,并通过试验和模拟结果的对比,验证了所提出方法和二次开发程序的有效性.应用含孪晶效应的晶体塑性有限元方法模拟分析了孔洞对于板材开孔问题的影响,结果表明:(1)当孔径小于板宽一半时,强度损失采用线性近似估算值是偏于安全的,而超过板宽一半时,不宜采用线性估算值;(2)当孔距较小时,孔径排布方式对开孔板材的韧性以及极限承载力有重要影响,排布方式可分弱影响区、强影响区和过渡区3种模式.对于承受单向拉伸荷载的板材,开孔时应选择沿轴线排布的方式.展开更多
The influence of crystallographic orientation on the void growth in FCC crystals was numerically simulated with 3D crystal plasticity finite element by using a 3D unit cell including a spherical void, and the rate-dep...The influence of crystallographic orientation on the void growth in FCC crystals was numerically simulated with 3D crystal plasticity finite element by using a 3D unit cell including a spherical void, and the rate-dependent crystal plasticity theory was implemented as a user material subroutine. The results of the simulations show that crystallographic orientation has significant influence on the growth behavior of the void. Different active slip systems of the regions around the void cause the discontinuity in lattice rotation around the void, and the corner-like region is formed. In the case of the void located at grain boundary, large heterogeneous deformation occurs between the two grains, and the equivalent plastic deformation along grain boundary near the void in the case of θ=45^o （θ is the angle between grain boundary direction and X-axis） is larger than the others. Large difference of orientation factor of the two grains leads to large equivalent plastic deformation along grain boundary, and the unit cell is more likely to fail by intergranular fracture.展开更多
文摘基于ABAQUS子程序VUMAT二次开发平台,将位错和孪晶的演化过程引入晶体塑性有限元方法(crystal plastic finite element method,CPFEM)中,实现了多晶塑性材料力学行为的有限元模拟,并通过试验和模拟结果的对比,验证了所提出方法和二次开发程序的有效性.应用含孪晶效应的晶体塑性有限元方法模拟分析了孔洞对于板材开孔问题的影响,结果表明:(1)当孔径小于板宽一半时,强度损失采用线性近似估算值是偏于安全的,而超过板宽一半时,不宜采用线性估算值;(2)当孔距较小时,孔径排布方式对开孔板材的韧性以及极限承载力有重要影响,排布方式可分弱影响区、强影响区和过渡区3种模式.对于承受单向拉伸荷载的板材,开孔时应选择沿轴线排布的方式.
基金Project(2005CB623706) supported by the Major State Basic Research Development Program of China
文摘The influence of crystallographic orientation on the void growth in FCC crystals was numerically simulated with 3D crystal plasticity finite element by using a 3D unit cell including a spherical void, and the rate-dependent crystal plasticity theory was implemented as a user material subroutine. The results of the simulations show that crystallographic orientation has significant influence on the growth behavior of the void. Different active slip systems of the regions around the void cause the discontinuity in lattice rotation around the void, and the corner-like region is formed. In the case of the void located at grain boundary, large heterogeneous deformation occurs between the two grains, and the equivalent plastic deformation along grain boundary near the void in the case of θ=45^o （θ is the angle between grain boundary direction and X-axis） is larger than the others. Large difference of orientation factor of the two grains leads to large equivalent plastic deformation along grain boundary, and the unit cell is more likely to fail by intergranular fracture.
