Because this problem is solved in five load steps, different boundary conditions (BCs) and loadings are imposed in each load step.
The pilot node, representing the gravity center of axle, is constrained. To simulate vehicle mass, one ton of gravity load is applied. An initial temperature of 20°C is applied at the pressure node.
d,1026,all ! 1026 represents the pilot node acel,0.,9810,0. bf,1,temp,20 ! 1 is the pressure node
To inflate the tire, the pressure node is constraint by applying a pressure boundary condition (hydrostatic pressure of 36 psi (0.2482128 N/mm2)). The constraint is equivalent to applying a surface load on the underlying solid surface.
d,1,hdsp,0.2482128
The tire is moved down to make contact with the road surface by applying the displacement boundary condition to the pilot node.
d,1026,uy,-50
All pressure and displacement boundary conditions are removed.
ddel,1026,uy,,,force ! Remove boundary conditions ddel,1026,rotx,,,force ddel,1026,roty,,,force ddel,1026,rotz,,,force ddel,1,hdsp ! Remove pressure boundary condition