Geometry-Driven Deformation and Degradation Behavior of Crimped Electrical Connections Under Coupled Environmental and Chemical Loading

Crimped electrical connections must maintain electrical continuity and mechanical load transfer capability under combined environmental and operational stressors throughout their service life. Although the environmental durability of electrical connectors has been extensively studied, previous studies have mainly focused on material, environmental, or electrical effects in isolation, whereas the coupled influence of crimp geometry on electrical–mechanical degradation and contact evolution remains insufficiently understood. In this study, crimp geometry was isolated as the primary independent variable to investigate geometry-driven degradation behavior in crimped connections. Three crimp configurations (Type A, Type B, and Type C) were subjected to temperature cycling (−55 °C to +70 °C), high humidity (90–95% RH), and combined chemical–electrical loading conditions involving representative fluids and short-circuit current. Electrical and mechanical responses were evaluated using relative resistance variation ΔR (%) and tensile strength change ΔT (%), while factorial ANOVA quantified parameter contributions. The results indicate that crimp geometry dominates the response under thermal–humidity exposure, whereas the chemical exposure type becomes the governing factor for electrical degradation under coupled chemical–electrical conditions. SEM analysis reveals that geometry-dependent plastic deformation governs contact continuity and void formation, leading to a transition from continuous conductive networks to fragmented contact structures. These findings are further supported by FEM analyses, which provide qualitative insight into the deformation response as a function of the geometric parameters. This work presents a geometry-based experimental framework for understanding the degradation behavior of crimped bonding structures under dual-exposure test conditions.