A continuum damage model for composite laminates: Part IV- Experimental and numerical tests

This paper follows on from part III (Llobet et al., 2020) where a mesoscale continuum damage mechanics (CDM) model for composite laminates under static and fatigue loads has been presented. An experimental investigation on the damage occurrence and the strength of carbon/epoxy notched laminates subjected to static, tension-tension fatigue and residual strength tests is provided. X-ray inspections reveal that matrix cracking, longitudinal splitting and delamination control the fatigue degradation process. This paper presents a coupled computational model to account for intralaminar damage using the CDM model and interlaminar damage using a cohesive zone model (CZM). The capability of the computational model to capture the main fatigue degradation mechanisms and the residual strength is examined by simulating open-hole and double-edge notched specimens. The numerical predictions show that the main fatigue degradation mechanisms are well captured as well as the post-fatigue residual strengths except for the open-hole specimen. Further experimental and modelling work are required to develop a more reliable computational tool for quantitative evaluation of fatigue and damage tolerance of composite structures.