Effect of delamination on the fatigue life of GFRP: A thermographic and numerical study. (15th June 2019)

• Record Type: Journal Article
• Authors: Colombo, Chiara; Bhujangrao, Trunal; Libonati, Flavia; Vergani, Laura
• Is Part Of: Composite structures. Volume 218(2019)
• Page Start: 152
• Page End: 161
• Publication Date: 2019-06-15
• Subjects: GFRP-composites -- Delamination -- IR-thermography -- Cohesive elements; Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2019.03.023
• Languages: English
• ISSNs: 0263-8223

Abstract

Abstract: Delamination is the major failure mechanism in composite laminates and eventually leads to material failure. An early-detection and a better understanding of this phenomenon, through non-destructive assessment, can provide a proper in situ repair and allow a better evaluation of its effects on residual strength of lightweight structural components. Here we adopt a joint numerical-experimental approach to study the effect of delamination on the fatigue life of glass/epoxy composites. To identify and monitor the evolution of the delamination during loading, we carried out stepwise cyclic tests coupled with IR-thermography on both undamaged and artificially-damaged samples. The outcome of the tests shows that IR-thermography is able to identify a threshold stress, named damage stress σD, which is correlated to the damage initiation and the fatigue performance of the composite. Additionally, we performed FE-simulations, implementing the delamination by cohesive elements. Such models, calibrated on the basis of the experimental fatigue results, can provide a tool to assess the effect of parameters, such as the delamination size and location and composite stacking sequence, on the residual strength and fatigue life of the composite material.