The steps in setting up a plastic hinge are illustrated below. The leg from A to B is overheated, causing bending of the B-D support leg. This example models the plastic deformation at cross-section E-E. The plastic hinge is formed between nodes 10 and 15. The plastic hinge is modeled as a zero length expansion joint with rotational bi-linear restraints. The expansion joint is used to provide translational and torsional rigidity at the plastic hinge junction. Two bi-linear supports are used to model rigid resistance to bending until a breakaway force (yield force) is exceeded, at which point bending is essentially free.
The yield force is computed using the following equation: Fy = SyZ(SF) Where Sy is the yield stress Z is the section modulus SF is the safety factor |