Screw Hole Fatigue in Aluminum Composite Panels: Safe Wind Speed Thresholds Using Hybrid Analysis

Abstract

Aluminum composite panels (ACPs) are extensively utilized in building facades, but need drilled holes for screw fixation, exposing them susceptible to environmental stresses. This study examines the impact of wind speeds (8–18.72 m/s) on the fatigue life of ACPs. Tensile and fatigue tests were performed on pristine specimens and panels featuring holes of 2, 3, and 4 mm in diameter. The experimental results indicated a significant decrease in fatigue endurance limits (after 10⁶ cycles), from 2.3 MPa for the unaltered specimen to 1.45 MPa, 1.424 MPa, and 1.37 MPa for the specimens with 2, 3, and 4 mm holes, respectively. ANSYS Workbench simulations analyzed a 1 m² ACP subjected to wind pressure to identify fatigue safety factors. This research determined the safe wind speed thresholds (with a safety factor of 1.25) as 14.41 m/s (pristine), 11.20 m/s (2 mm), 11.12 m/s (3 mm), and 10.79 m/s (4 mm). Results from experiments indicated fatigue limits of 2.3 MPa (pristine), 1.45 MPa (2 mm), 1.424 MPa (3 mm), and 1.37 MPa (4 mm). The pristine specimen exhibited superior fatigue resistance due to the absence of stress concentrations. Dynamic study indicated safe wind speeds of 14.41 m/s (pristine), 11.2 m/s (2 mm), 11.12 m/s (3 mm), and 10.79 m/s (4 mm). Hole diameter directly reduces fatigue performance and allows wind loads. The existence of a 4 mm aperture diminished the fatigue endurance limit by roughly 40% and the safe wind speed threshold by 25% in comparison to the unblemished panel.