A hysteretic connection element and its applications

A hysteretic connection element for the simulation of hysteretic responses of connections is formulated and implemented in the non-linear finite element program DRAIN-3DX. In the formulation of the element, both stiffness-and-strength degradation and pinching are expressed as functions of damage state variables; meanwhile, damage is monitored and failure is detected by means of a damage index. In the implementation of the element, an automatic event definition algorithm is developed and an event-to-event solution scheme is followed. The element is applied to the simulation of hysteretic responses of unstiffened extended end plate connections, web panels, joints and frame substructures subject to cyclic reversal loading. Simulations are in good agreement with experimental data in terms of load-deformation relationship, strength, stiffness, and energy dissipation.