Damage Growth Study in Unidirectional CFRP Composites Using Infrared Thermography

Abstract

Structural integrity evaluation of composite structures requires a comprehensive understanding of the various failure mechanisms like matrix cracking, fiber breakage, fiber-matrix interface failure, delamination, and their evolution across micro-to-macro scales. Non-destructive testing and evaluation (NDT&E) techniques are applied to composite structures for discerning the various damage mechanisms and provide information for numerical life estimation tools. Among the NDT methods, infrared thermography is one of the modern non-invasive techniques suited for real-time monitoring and gives in situ information regarding the onset of damages and its growth. In this work, the aim is to investigate damage initiation and progression in unidirectional carbon fiber reinforced plastic (CFRP) composite under static loading condition. The passive thermography (PT) and active thermography techniques are employed in damage growth studies in CFRP laminate using an infrared camera. The PT experiments were carried out to examine the damage information in the thermograms under monotonic ramp loading. Image processing of the thermal images obtained using thermography is used to get qualitative information about the damage evolution in unidirectional CFRP specimens.