钢梁腐蚀后钢–混凝土组合梁疲劳性能研究

Study on Fatigue Performance of Steel-Concrete Composite Beams Subjected to Corrosion of Steel Beams

摘要: 为了研究钢梁腐蚀后钢–混凝土组合梁疲劳性能，本次试验共设计制作了6根力学性能相同的组合梁，其中1根梁进行静力试验，5根梁进行疲劳试验。静力试验提供组合梁的极限荷载，为疲劳试验确定荷载幅提供了依据。本研究重点比较了在不等幅加载下，不同疲劳加载次数对组合梁破坏形态的影响，并分析了荷载–挠度曲线、残余挠度及相对滑移量的变化。对相关试验数据进行分析及处理，深度探讨刚度退化的根本原因。通过对实验数据的深入分析，探讨了刚度退化的根本原因。研究结果表明，荷载幅的增加导致组合梁疲劳寿命降低，并产生不可恢复的残余变形和应变，残余挠度也随之上升。同时，组合梁的刚度在疲劳加载过程中出现了一定程度的退化，弯曲刚度的退化率随着荷载幅的增加而增大。

Abstract: In order to study the fatigue performance of steel-concrete composite beams after the corrosion of steel beams, a total of six composite beams with the same mechanical properties were designed and fabricated in this experiment. One beam was subjected to static testing, and five beams were subjected to fatigue testing. Static testing provides the ultimate load of composite beams and serves as a basis for determining the load amplitude in fatigue testing. This study focuses on comparing the effects of different fatigue loading cycles on the failure modes of composite beams under unequal amplitude loading and analyzing the changes in load-deflection curves, residual deflection, and relative slip. Analyze and process relevant experimental data and deeply explore the fundamental causes of stiffness degradation. Through in-depth analysis of experimental data, the fundamental cause of stiffness degradation was explored. The research results indicate that an increase in load amplitude leads to a decrease in the fatigue life of composite beams, as well as irreversible residual deformation and strain and an increase in residual deflection. Meanwhile, the stiffness of the composite beam undergoes a certain degree of degradation during fatigue loading, and the degradation rate of bending stiffness increases with the increase of load amplitude.