Establishment of a dynamic three-dimensional failure envelope model for single-lap riveted joints in plain weave CFRP composite

Currently, the mechanical behavior of riveted joint structures in plain weave composite materials under complex loading conditions has not been systematically and comprehensively investigated. An accurate understanding of the load-bearing capacity and failure characteristics of these structures is crucial for engineering application and optimal design of composite riveted joints. In this study, quasi-static loading tests were conducted on nine different specimen configurations, thoroughly analyzing both the in-plane and out-of-plane anisotropic characteristics of riveted joints. Based on the experimental results, a quasi-static three-dimensional failure envelope model was established to accurately describe variations in ultimate load capacity concerning loading angles, identifying three critical characteristic loading angles. Dynamic tests using an electromagnetic split Hopkinson tensile bar (ESHTB) were subsequently performed at these characteristic loading angles, examining the structure's load-bearing capabilities and dynamic effects at high strain rates, thus extending the failure envelope to dynamic loading conditions. Furthermore, by integrating optical microscopy and an equivalent cross-ply laminate (ECPL) finite element model, the micro-mechanisms responsible for anisotropic failure behavior under quasi-static loading and enhanced load-bearing capacity under dynamic loading conditions were investigated. Simulation results demonstrated strong consistency with microscopic observations, further validating the reliability of the developed model and its effectiveness in evaluating the structural performance of practical composite riveted joints. This research enhances the understanding of mechanical behaviors of riveted composite joints under complex conditions, providing a robust theoretical foundation for engineering design and optimization.