基于临界平面法的混凝土疲劳寿命预测研究

利用疲劳分析的临界平面方法和有限元分析手段,以塑性应变能密度为损伤参量,计算混凝土疲劳试件在疲劳载荷作用下的累积损伤,得到损伤累积规律,结合实验结果建立疲劳损伤累积方程,并得到临界最大累积损伤及其产生的位置.考虑载荷水平的影响,得到规范化的临界塑性应变能密度和应力水平的关系方程.结合疲劳损伤累积方程和损伤与应力水平关系方程,对试件疲劳寿命进行预测,预测结果与实验结果吻合很好.

Approach of Fatigue Life for Concrete Based-on Critical Plane Method

Based-on the method combine the critical plane with the finite element analysis,fatigue damage parameters were defined as the plastic energy density on the critical plane.The damage accumulation laws for concrete specimen were calculated under fatigue loads,and fatigue damage accumulation equations were built according to the experimental data,hence critical maximum accumulation damage and location were determined.Take influence of stress level into account,the relationship of critical plastic energy density with stress was normalized,and relationship equation was built.Used both damage equations and relationship equation,fatigue lives of concrete specimen were predicted,the result was satisfying compared with experimental.