Effect of microdamage on the failure of open-hole UD GFRP laminates: A combined experimental and numerical study

Abstract

The effect of microdamaging on the failure of unidirectional Interglas 92145/CR80 GFRP laminates is studied through experiments and a numerical approach combining Enhanced Schapery Theory (EST) and Crack Band Theory (CBT). Open-hole tension tests with various layer configurations, along with flat tensile tests were conducted to examine failure modes and their progression. The initiation and development of failure mechanisms were tracked experimentally using DIC imaging. In the numerical model, the matrix microdamage is represented through dissipated energy-dependent functions derived from standardized mechanical tests. Without discretely modeling splitting cracks, the numerical approach captured narrow zones of fiber and matrix failure coincident with experimentally observed crack paths. Axial, transverse, and shear strain fields from the physical and virtual tests were compared at the critical stages of the testing regimen. Comparison of the strain fields, as well as stress-strain curves from the numerical and experimental studies showed good agreement, suggesting that incorporation of microdamage modeling—rarely implemented in progressive failure analyses—offers potential for improving failure predictions in GFRP laminates.