Hi, , thx for your reply, actually, I considered converting force into velocity by equation v = v0 + a*dt, and then adopting profile to realize this motion, however, I think this method will bring some error(in other words, I want to get an fully accurate result), furthermore, I also want to make a comparison between this two method, thus, I need to get this skill. And in some cases, the force cannot be expressed by function, it consists of a number of points.nFor your question, in previewing mesh motion, once I have finished the dynamic mesh settings, if the UDF or Profile is correct, I can preview the motion of assigned moving wall.nRegardsnn