Phenomenological hysteretic model for fixed-end steel equal-leg angle: Development and application

Abstract

Hysteretic behaviors of steel members are of great significance in the assessment of the realistic ultimate capacity of steel structures subjected to dynamic overloads (e.g. strong earthquakes). To this end, this paper intends to develop a new phenomenological hysteretic model for capturing the inelastic behaviors of steel equal-leg angles, which is extensively used in a latticed steel tower. Specifically, cyclic tests of steel angles were performed, and a 3D finite element (FE) model is developed and validated based on the experimental results. Numerical parametric analyses are then performed to investigate the influences of slenderness ratios, width-to-thickness ratios, and initial imperfections on the hysteretic behaviors of steel equal-leg angles. Based on the parametric results, a phenomenological hysteretic model is proposed to replicate the hysteretic behaviors of steel angles, and its accuracy is demonstrated by further comparing against the experimental results. Finally, the proposed phenomenological hysteretic model is coded into the commercial package ABAQUS and used to simulate the dynamic responses and collapse of a latticed tower under severe earthquakes. The results show that the proposed phenomenological hysteretic model shows high fidelity in reproducing the nonlinear hysteretic behaviors of steel equal-leg angles subjected to cyclic loads. This research can enrich the existing hysteretic models of steel members and provide an accurate method for estimating the realistic responses of steel structures subjected to strong dynamic overloads.