Damage mechanisms of bismaleimide matrix composites under transverse loading via quasi-static indentation

Abstract With the application of carbon fiber reinforced plastics (CFRPs), damage behaviors and mechanisms are desirable to understand. In this work, Bismaleimide (BMI) matrix composites were employed study mechanism under transverse loading through quasi-static indentation, where optical microscopy, ultrasonic C-scan, scanning electron microscope subjected examine damaged regions. The results show that cracks first take place in a resin-rich interlaminar region before reached threshold value. Then, would develop into intralaminar bundle consisting shear bending cracks. Subsequently, randomly extend adjacent plies result delamination. Finally, back surface presents remarkable ply splitting breakage increasing loading. Furthermore, conical-shaped indentation patterns cross-sectional undamaged zone indenter suggest BMI possess potential applications engineering materials with superior stress-releasing structure.