钢筋混凝土梁疲劳累积损伤过程的等效静力分析方法

摘要

In order to achieve the full-range analysis and prediction of residual bearing capacity of concrete beams under high-cycle fatigue loading effectively, an equivalent static analysis method for fatigue cumulative damage process of concrete member was proposed. Firstly, according to the rules on stiffness degradation, strength reduction and the accumulation of residual deformation of materials under the fatigue loading, fatigue constitutive model of concrete and reinforced rebar in any cycle of the fatigue load were established. Based on the similarity of concrete behavior under static load and that under fatigue load, the equivalent relation was built. The equivalent static analysis method for fatigue performance of reinforced concrete member was proposed. A reinforced concrete simple-supported beam was simulated for the fatigue behavior by the method as an example. The results show that the numerical analysis results are consistent with the test results. The effectiveness and practicability are testified.%为了实现对钢筋混凝土梁疲劳性能的全过程分析和剩余承载力评估，提出一种混凝土构件疲劳累积损伤过程的等效静力分析方法。通过对材料疲劳刚度、强度退化和疲劳残余变形累积发展规律进行分析研究，建立混凝土和钢筋任意加载次数后的疲劳本构模型；基于混凝土材料在静态荷载与疲劳荷载作用下破坏的相似性，构建疲劳荷载与静载作用的等效关系，提出钢筋混凝土构件疲劳性能的等效静力分析方法。采用该方法对某混凝土试验梁进行疲劳性能分析。研究结果表明：所获得的数值模拟结果与实验值变化规律一致，吻合程度良好，验证了该方法的有效性和实用性。