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.

Automated summary

This paper continues the study on damage mechanisms of composite laminates under static and fatigue loads, investigating the effects of intralaminar and interlaminar damage on residual strength through experiments and numerical simulations. The results show that the main fatigue degradation mechanisms are well captured in the simulations, except for the open-hole specimen which needs further improvement.