带锈蚀栓钉的组合梁疲劳后抗弯承载力影响因素分析

Analysis of influencing factors on flexural capacity of composite beams with corroded studs after fatigue

为了探索钢-混组合梁锈蚀和疲劳后抗弯承载力的影响因素,开展了组合梁的理论和试验研究.基于断裂力学和疲劳剩余强度理论得到栓钉、钢梁和混凝土的剩余强度,在此基础上建立了一种组合梁抗弯承载力的计算方法,并利用5个试验梁进行了验证,最后选取混凝土强度、栓钉直径、疲劳加载上限、栓钉锈蚀率等影响因素进行参数分析.结果表明:随着栓钉锈蚀率增大,抗弯承载力呈现先慢后快的退化趋势,当锈蚀率为20%时,组合梁抗弯承载力下降9.1%;所建模型与试验值较为吻合,表明该模型具有良好的适用性;混凝土强度、疲劳加载上限、栓钉锈蚀率以及栓钉数是影响组合梁抗弯承载力的主要因素.

In order to explore the factors affecting the flexural capacity of steel-concrete composite beams after corrosion and fatigue,this paper conducts theoretical and experimental research on the composite beams.Based on fracture mechanics and the theory of fatigue residual strength,the residual strength of studs,as well as that of steel beams and concrete,are determined.Based on this,a calculation method for the flexural capacity of composite beams is established,and the data of 5 test beams are used for verification.Finally,the influencing factors such as concrete strength,stud diameter,upper limit of fatigue loading,and stud corrosion rate are selected for parameter analysis.The results show that with the increase of stud corrosion rate,the flexural capacity shows a degradation trend of first slowing down and then accelerating,and when the corrosion rate reaches 20%,the flexural capacity of the composite beam decreases by 9.1%.The established model is in good agreement with the experimental values and has good applicability.Concrete strength,upper limit of fatigue loading,stud corrosion rate,and number of studs are the main factors affecting the flexural capacity of composite beams.