Specification of non-uniform residual stresses and tensile characteristic in laminated composite materials exposed to simulated space environment

Abstract

In this study, the impact of the low earth orbit environment on multi-layered glass fiber reinforced polymer (GFRP) composites is analyzed in detail. The material responses are characterized through an assessment of residual stresses and mechanical property changes. To follow this aim, a thermal cycling condition was provided and composite samples were exposed to cyclic temperature variations with different number of thermal cycles. Then, the slitting method as an accurate semi-destructive technique was accomplished to characterize the non-uniform residual stresses through the depth of GFRP laminates. Additionally, tensile strength and mechanical properties were examined conducting tensile test. The results signified that residual stresses are reduced as the composites undergo temperature fluctuations. Finally, based on experimental results, a quadratic equation was proposed to predict the tensile strength of GFRPs exposed to thermal cycling condition. The proposed model was successfully verified and proved to be accurate with the error of less than 5%.