预应力CFRP修复含裂纹钢板疲劳寿命的延长预测

Prediction on fatigue life prolongation of cracked steel plate repaired with prestressed CFRP

为研究预应力碳纤维复合材料(carbon fiber reinforced polymer,CFRP)修复对于海上油气勘探开发平台上含裂纹钢板的疲劳寿命的延长效果。基于围线积分方法建立计算预应力CFRP修复含裂纹钢板应力强度因子(stress intensity factor,SIF)的仿真分析模型,结合线弹性断裂力学,验证模型的准确性,提出1种简单、高效的SIF计算方法;基于扩展有限元方法(extended finite element method,XFEM)建立预测预应力CFRP修复含裂纹钢板疲劳寿命的仿真分析模型,并利用疲劳试验结果进行验证,分析预应力对含裂纹钢板疲劳寿命的延长效果。研究结果表明:CFRP修复对含裂纹钢板有良好的修复效果,可较为明显地延长其疲劳寿命,随着预应力的增大,其延长效果会进一步增强。研究结果可为海上平台安全评估提供参考。

To investigate the effect of prestressed carbon fiber reinforced polymer(CFRP)on the fatigue life prolongation of cracked steel plates utilized on offshore oil and gas E&P platforms,a simulation analysis model for calculating the stress intensity factor(SIF)of cracked steel plate repaired with prestressed CFRP was established based on the contour integral method.The accuracy of the model was verified combining with the linear elastic fracture mechanics,and a simplified and efficient method for calculating SIF was proposed.Based on the extended finite element method(XFEM),a simulation analysis model for predicting the fatigue life of cracked steel plate repaired with prestressed CFRP was constructed and validated by the fatigue test results,and the effect of prestress on the fatigue life prolongation of cracked steel plate was studied.The results show that CFRP repair has a good effect on the cracked steel plate and can prolong its fatigue life more obviously,with the increase of prestress,its prolongation effect will be further enhanced.The research results can provide reference for the safety assessment of offshore platforms.