Numerical Study of the Section Moment Capacity of Complex-Shaped Aluminum Mullions

Abstract

Curtain wall systems made of an aluminum frame and infilled with glass panes are extensively used in present day high-rise buildings. The vertical members of the aluminum frame, known as mullions, are complex-shaped and are primarily subjected to bending action when the curtain wall panels are exposed to wind pressure or suction loading. This paper investigates the section moment capacity of 6063-T6 aluminum alloy mullion sections subjected to wind actions using a numerical study. An experimental study conducted to determine the section moment capacity of the mullions is summarized in this paper. The results from an experimental study on the mechanical properties of 6063-T6 aluminum alloy mullions are then presented including a suitable stress–strain model. Finite element models were developed to determine the section moment capacities of tested mullion sections, and the details of the finite element modeling procedure and the results are presented in this paper. The developed models included mullions used in the structural and captive glazing systems subjected to both wind pressure and suction loading and were validated using the available test results. Finite element analysis (FEA) results were compared with the predictions from three design methods, the limiting stress method (LSM), the direct strength method (DSM), and the total moment capacity approach (TMCA), based on which the most suitable design method is recommended.