西部地区混凝土基于Weibull分布的寿命预测研究

Study of Lifetime Prediction of Concrete in Western Region Based on Weibull Distribution

对混凝土试件进行了模拟特殊自然环境条件下的加速失效试验,并得到了加速寿命数据.首先,结合寿命数据采用Weibull分布函数对其退化过程进行建模;其次,应用不同参数估计方法得到了基于Weibull分布参数的估计值;最后,建立了服役寿命的可靠度函数及概率密度函数.结果表明:Weibull分布函数可以有效地描述混凝土试件的加速耐久性能退化过程,建立的混凝土加速寿命可靠度函数能够直观地反映试件的服役寿命,并且与试验结果较一致;在参数估计方法的适用性方面,最小二乘法以及极大似然估计法比较适合小样本完全寿命数据的情况,这为混凝土加速失效试验的寿命预测及可靠性评估提供了直接而有效的参数估计方法.

An accelerated failure test of concrete was conducted in a special natural environment,and accelerated life data were obtained.Firstly,the Weibull distribution function was used to model the degradation process by combining the life data.Then,the parametric estimation of the Weibull distribution was proposed by using different parameter estimation methods.Finally,the reliability and probability density functions of service life were established.The results showed that the Weibull distribution can describe the durability degradation of concrete specimens effectively.By using this method,the accelerated life reliability function of concrete can reflect the service life of the specimen directly,and the experimental value is in good agreement with the lifetime prediction.In applying the parameter estimation method,the least square(LSE)method and maximum likelihood estimation(MLE)methods are suitable to obtain complete life data for small samples.This provides a direct and effective method to estimate the parameters for lifetime prediction and reliability evaluation of the accelerated failure test of concrete.