钢纤维增强高性能混凝土弯曲疲劳寿命预测研究

Fatigue Life Prediction Models of Steel Fiber Reinforced High Performance Concrete

研究纤维体积掺量(0.5%,1.0%和1.5%)对高性能混凝土疲劳性能影响,在不同应力水平(S=0.65,0.70,0.75和0.80)下对钢纤维增强高性能混凝土(FRHPC)进行四点弯曲疲劳试验。基于两参数威布尔分布理论,应用图像法、矩估计法、最大似然估计法,求出威布尔形状参数a和特征寿命参数u,对不同失效概率下混凝土的疲劳寿命进行预测,建立双对数疲劳方程。研究结果表明:不同应力水平下混凝土弯曲疲劳试验数据符合两参数威布尔分布,纤维对混凝土疲劳性能有提升作用,提出了考虑失效概率的P-S-N曲线方程。纤维增强高性能混凝土疲劳寿命的预测方法和试验结果可以为工程应用提供基础理论。

In order to investigate the effect of fiber volume fractions(0.5%,1.0%and 1.5%)on the fatigue properties of HPC,four-point bending fatigue tests were carried out under different stress levels S(0.65,0.70,0.75 and 0.80)on Fiber Reinforced High-performance Concrete(FRHPC).Based on the two-parameter Weibull distribution theory,the Weibull shape parameter a and the characteristic life parameter u are obtained by graphical method,moment estimation and maximum likelihood estimation.The fatigue life of FRHPC under different failure probabilities is predicted,and the double logarithm fatigue equations are established.The experimental results show that the flexural fatigue test data of FRHPC under different stress levels conform to the two-parameter Weibull distribution.Fiber can improve the fatigue performance of HPC.Based on the Weibull distribution test of FRHPC specimens fatigue life,the P-S-N curve equations taking account of failure probability was proposed.The prediction method and test results of fatigue life of FRHPC can provide basic theory for engineering application.