Application of Thermoelastic Potential Theory to Statistical Investigation of Interfacial Thermal Stress in FRP

Abstract

The interfacial stress between fibers and matrix plays an important role in the durability and damage initiation of carbon fiber reinforced composites. In this study, thermoelastic analysis was performed on a plate containing randomly distributed multiple fibers. Complex stress functions were employed with a semi-numerical method to ensure displacement continuity along the fiber/matrix interface as a boundary condition. The statistical investigation reveals that the stress concentration due to the presence of multiple fibers increases as the fiber density increases, though its deviation decreases. A numerical case study was conducted to discuss the micromechanics of the inherent scatter of material strength. The stress-strength model with Monte-Carlo simulation demonstrated the fracture probability calculation. The uncertainty obtained is partially attributed to the micromechanical stress distribution around the fibers.