碳纤维复合材料预湿热条件下疲劳寿命退化规律OA

This study aims to reveal the fatigue life degradation mechanisms of carbon fiber reinforced polymer(CFRP)composites under pre-hygrothermal environments.The static tensile strength and fatigue life of composites were investigated under four moisture absorption conditions(0%,40%,70%,and 100%of saturated moisture con-tent).The static tensile failure stress exhibited fluctuating characteristics,while the fatigue life showed a monotonic decreasing trend with increasing moisture absorption.The fatigue life distribution patterns of laminates under different stress levels were analyzed using log-normal distribution and two-parameter Weibull distribution theories,both demonstrating excellent fitting accuracy.Based on log-normal distribution analysis,the reliability life decreased with increasing reliability levels and increased with decreasing stress levels.The hygrothermal fatigue failure modes manifested as multiple damage mechanisms involving fiber bundle fracture spanning the entire working section and delamination damage.These findings provide theoretical support for the engineering application of composites in hy-grothermal environments.