Delamination mechanisms in fiber-reinforced composites structures tested at different loadings

Abstract

Composite materials are a special class which has some advantages like low weight, high strength and stiffness. For a composite system they are very suitable for aerospace, marine and auto applications due to the low density. Among all the synthetic fibers, carbon fibers are now considered the first material to be used for reinforcement due to their proper cost, as compared to aramid, and better mechanical and physical properties. This paper is an experimental work and presents the preliminary results regarding the evaluation of CFRP prepreg based on M18/1 carbon fiber prepreg developed by manual lay-up/autoclave curing. The obtained materials were tested at different mechanical loads and the failure mode was analyzed with the aim of evaluating their performances. The mechanism by which the fibers are delaminated in the composite system is assessed. To verify if the structure has defects that can interfere with the delamination process, ultrasonic nondestructive testing has been used. Also, for a better understanding of the delamination mechanism, the numerical simulation was used.

Keywords

• delamination
• composite materials
• autoclave
• mechanical testing
• ndt testing
• optical microscopy
• prepreg