Mechanical model and finite element analyses of the T-stub joint component in fire

Abstract

This article presents a mechanical model, based on thin plate theory and which incorporates the thermal degradation of material properties, to investigate the behavior of T-stub assembly, in terms of resistance, stiffness, deformation capacity, and failure modes at different temperatures. Also, a three-dimensional finite element model is developed to simulate the performance of T-stub. The proposed two models are validated against T-stub experiment available in other literature, and it is shown that the models proposed in this article satisfactorily predict the behavior of a T-stub assembly exposed to fire. Then, a thorough parametric study is conducted. The key variables include flange thickness, bolt grade, the distance from bolt line to flange root, and the temperature of the T-stub. Two kinds of loading paths, namely, “loading under constant temperature” and “heating under constant load,” are also adopted. The parametric study provides some valuable suggestions to improve the performance of T-stub and to refine the T-stub configurations.