arctrm

Mapdl.arctrm(lab='', val='', node='', dof='', **kwargs)

Controls termination of the solution when the arc-length method is

APDL Command: ARCTRM used.

Parameters:

lab

Specifies the basis of solution termination:

OFF - Does not use ARCTRM to terminate analysis (default).

L - Terminates the analysis if the first limit point has been reached. The first

limit point is that point in the response history when the tangent stiffness matrix becomes singular (i.e., the point at which the structure becomes unstable). If Lab = L, arguments VAL, NODE, DOF are ignored.

U - Terminates the analysis when the displacement first equals or exceeds the

maximum desired value.

val

Maximum desired displacement (absolute value). Valid only if Lab = U. The analysis terminates whenever the calculated displacement first equals or exceeds this value. For rotational degrees of freedom, VAL must be in radians (not degrees).

node

Node number corresponding to displacement used to compare with displacement specified by VAL. If blank, the maximum displacement will be used. Valid only if Lab = U.

dof

Valid degree of freedom label for nodal displacement specified by NODE. Valid labels are UX, UY, UZ, ROTX, ROTY, ROTZ. Valid only if NODE>0 and Lab = U.

Notes

The ARCTRM command is valid only when the arc-length method (ARCLEN,ON) is used.

It can be convenient to use this command to terminate the analysis when the first limit point is reached. In addition, the NCNV command should be used to limit the maximum number of iterations. If the ARCTRM command is not used, and the applied load is so large that the solution path can never reach that load, the arc-length solution will continue to run until a CPU time limit or a “maximum number of iterations” is reached.