疲劳荷载作用下的混凝土变形规律

通过混凝土疲劳试验,总结并验证了疲劳荷载下混凝土变形的一般规律:三阶段演变规律和第2阶段临界应变的不变性。讨论了上述规律的使用条件,其中三阶段演变规律属于普遍规律,与混凝土强度以及荷载形式无关;第2阶段临界应变的不变性只适用于强度等级相同的混凝土材料,但与加载历史无关。基于上述变形规律提出计算混凝土疲劳寿命的公式,该公式可用于预测现役混凝土结构的剩余疲劳寿命。

Deformation laws of concrete under fatigue loading

Based on experiments on concrete specimens subjected to fatigue loading, the applicability of the three- stage deformation law and the invariance of the critical strain in the second stage are inspected. It is demonstrated that the three-stage law is universally applicable and has nothing to do with concrete strength and load form, and that the invariance of the critical strain in the second stage is only suitable for concrete materials with the same strength grade and has nothing to do with the loading history. A formula for calculating the fatigue life is put forward based on the above deformation laws, and the formula can be used to predict the residual fatigue life of existing concrete structures.