压缩实验模拟求助

zhyb

请问在模拟试件的准静态和动态压缩问题时，试件上端的加载条件通常如何引入？即加载刚块是以实体的形式还是壳单元的形式，或者直接采用刚性墙？

lfhaian

建议学习时党勇《基于ANSYS/LS-DYNA 8.1进行显式动力分析》 中的第六章泰勒杆冲击

zhyb

谢谢您的回帖！
那个例子里涉及到的是固定刚性墙，在dyna的关键字手册中有*RIDIGIDWALL_PLANAR_MOVING来给定其初始速度，或者利用*RIGIDWALL_GEOMETRIC_{OPTION}_{OPTION}来指定恒定位移和恒定速度的。我想问的是，通常对于准静态或者动态加载模拟，如果不采用刚性墙的关键字来定义，而将加载物采用壳单元或者实体单元的形式，其材料定义为刚体，即*MAT_RIGID，那么是否对该材料的性能参数要求较精确才能确保计算结果正确？

water

Your example is tested. It works in the new version of ls-dyna. You can contact with your distrobutor to get new version of ls-dyna.  But for your *CONSTRAINED_SHELL_TO_SOLID on the top of workpiece, I do not think this is a good choice. Constraining two nodes in one shell element at their fiber direction brings some difficulties for shell deformation.

I set the solid material as Rigid, it also works. You can try, but I hope you can choose other option to conatrain the nodes one the top of workpiece.

I attach one other example with boxbeam, maybe you can get some help from it.

I also attached final figure of your example.

water

one other example