Investigation of progressive damage behavior of uncured GLARE: An integrated study using in-situ acoustic emission and multi-scale simulation

This study investigates the progressive damage evolution and formability of thin-walled structural material- uncured GLARE laminates under complex stress states through a combination of Nakajima tests, in-situ acoustic emission (AE), and multi-scale simulation techniques. A mutation phenomenon caused by internal fiber premature cracking was observed both in punch force and strain field evolution, which was substantiated by a pronounced surge in AE energy accumulation. A novel systematic multi-scale simulation framework, integrated macro-, meso‑, and micro-scale, was developed to analyze the wrinkling and cracking mechanism. Macro-scale analysis demonstrated that increasing specimen width induces a significant reduction in stress triaxiality from 0.67 to -0.73 at the edge regions of aluminum alloy layers, directly responsible for wrinkling defect initiation. In contrast, fabric shear angle variations remained below 5°, confirming their negligible contribution compared to triaxiality-driven defect. Subsequent meso‑scale simulations revealed polar fiber turns the compression-tension to the biaxial tension status with width increasing, while micro-scale analyses tracked progressive damage accumulation patterns. This work delivers a robust predictive methodology and practical guidelines for accurately forecasting deformation-induced defects, thereby facilitating more reliable process optimization and component design for uncured GLARE laminates.