Web crippling behaviour of high-strength aluminium alloy channel-shaped members with strengthened web holes: Numerical study and new design rules

This study presents a detailed numerical investigation of 7075-T6 and AA-6086 high-resistance aluminium alloy channel-shaped members with strengthened web holes in web crippling. A nonlinear finite element (FE) model was developed and validated against the test results reported by the authors and other researchers. The material properties of 7075-T6 and AA-6086 high-resistance aluminium alloy were also obtained from the literature. Utilising this validated model, an extensive parametric study including 1296 models was carried out. This study examined both cases with clamped and unclamped flanges, and the variables were web thickness, bearing lengths, diameter of web holes, stiffener lengths, internal corner radii, and grades of aluminium alloys. Given the absence of existing standards for calculating the web load-bearing resistance of such members with strengthened web holes, the numerical results obtained from the parametric study were used to develop new design formulas with new coefficients through regression analysis. The design strengths calculated by the proposed design formulas were then compared against the FE results. Finally, a reliability analysis was also performed, demonstrating that the proposed design formulas can accurately predict the web load-bearing resistance for these members.