Hey Guys! Currently I am trying to handle crashworthiness of lattice structure. According to literature there are couple methods which is used mostly. I attached one of them into this topic. The Top plate is moving downward with constant 2mm/ms and total analysis took place 30 ms ( which I assume 30 ms as endtime-termination) Here first question, With constant velocity can ı use INITIAL_VELOCITY_RIGID instead of BOUNDARY PRESCRIBED MOTION ? Cause Whenever I use boundary prescribed motion card, I never get rigid top plate move. I dont know why but somehow plate is not moving downward. And another question is about time and Ls dyna units. I am newbie in this software and try to figure time units out. The reference article is utilising kg, mm, ms, KN, GPa units. I do applied all MAT card and velocity in terms of reference units. But my mind is perplexed. I need to apply 2 mm/ms for 30 ms and that is quite hard to run.It lasts rougly 7 days which is not possible to wait. Am ı doing something wrong with velocity and end time units. When ı use initial velocity with 20 and 3 endtime ı can see the results.