Apply a force on a wall

JF's picture
Submitted by JF on Fri, 04/12/2013 - 15:46

Hello,

I am discovering a very interesting function "mesh/surface/stress/servo" which enables to apply a force on a wall.

fix servo all mesh/surface/stress/servo file plate.stl type 1 com 0. 0. 0. ctrlPV force dim z set_point -10 vel_max 1.

First, I would like to know, what is the parameter 'set_point' in your example ?

Then, I would like to apply a force (10N) on two walls (top and bottom) to perform a compression test in the Z-direction.

#========= Script =============
fix topwall all mesh/surface/stress/servo file topwall.stl type 3 com 0.004 0.004 0.01 ctrlPV force target_val -10 dim z vel_max 1.
fix bottomwall all mesh/surface/stress/servo file bottomwall.stl type 3 com 0.004 0.004 0.00 ctrlPV force target_val 10 dim z vel_max 1.
fix wall all wall/gran/hertz/history mesh n_meshes 2 meshes topwall bottomwall
#==========================

My problem is the top wall doesn't move and the bottom wall moves away.

Please can you give me some advice to fix this problem.

Thanks in advance.
JF

PS: I have chosen the centre of mass as the center of the wall which is constituted by two triangles