Definition of Support Failure

Tips & Tricks

000863 8 August 2014

Supports contributing to a load reduction only under compression or tension can be defined as nonlinear supports in RFEM and RSTAB. It is not always easy for the user to select the proper nonlinearity for ‘failure under tension’ or ‘failure under compression’.

Since the support definition must be generally valid, the nonlinearity specification always refers to the coordinate system X',Y'Z' of the support.

If a support is defined with ‘Failure if negative PZ'’, then the support becomes ineffective when the ‘acting support force’ related to the coordinate system of the support is applied against the Z' axis (left system in Figure).

If a support is defined with ‘Failure if positive PZ'’, then the support becomes ineffective when the ‘acting support force’ related to the coordinate system of the support is applied in the direction of the Z' axis (right system in Figure).