Transverse mechanical properties of unidirectional FRP including resin-rich areas

Abstract

Fiber reinforced plastic (FRP) is known to possess advantages of high strength and low density, and it is extensively used in engineering structures. However, most FRP have a certain level of microstructural uncertainty, and resin-rich areas in FRP can exist as inter-lamina resin layers or intra-lamina resin pockets. This work proposes a new algorithm to generate non-uniform random fiber distribution which contains resin-rich areas. The transverse tensile and compressive mechanical behavior of unidirectional FRP including resin-rich areas are studied using numerical simulation. The representative volume element (RVE) of the FRP with resin-rich areas is constructed. Matrix plastic deformation and interfacial debonding are described by extended Drucker-Prager model and cohesive zone model. Detrimental effect of resin-rich areas on the mean values and uncertainty of transversely ultimate strength and fracture strain is quantified. A new observation is that the resin-rich areas would result in large uncertainty on the ultimate strength of FRP, while its influence on the mean values of ultimate strength and fracture strain is limited. The large uncertainty on the tensile strength is attributed to that different morphology of resin-rich areas would lead to different cracks. The size of the resin-rich areas is also found to have an effect on transverse tensile and compressive mechanical properties.