新型不锈钢可拆卸螺栓连接件疲劳后剩余力学性能研究  

Residual mechanical properties of new stainless steel detachable bolt connector after fatigue

作　　者：单江北 刘小玲 汪炳 SHAN Jiangbei;LIU Xiaoling;WANG Bing(College of Maritime and Transportation,Ningbo University,Ningbo 315211,China;School of Civil and Environmental Engineering,Ningbo University,Ningbo 315211,China)

机构地区：[1]宁波大学海运学院,浙江宁波315211 [2]宁波大学土木与环境工程学院,浙江宁波315211

出　　处：《振动与冲击》2023年第5期245-252,共8页Journal of Vibration and Shock

基　　金：浙江省自然科学基金项目(LQ19E080006);国家自然科学基金项目(51808301)。

摘　　要：为适应装配式组合梁的发展,研发一种新型不锈钢可拆卸螺栓连接件,并对其疲劳荷载作用下的力学性能退化规律开展研究。首先,通过文献和市场调研,充分考虑现有螺栓的优缺点,设计制作一种新型不锈钢可拆卸螺栓连接件用于装配式组合梁;其次,制作6组新型螺栓连接件的推出试件,进行静载和疲劳试验,对比静载与不同疲劳加载次数后试件的破坏形态,重点分析新型螺栓连接件在疲劳加载过程中剩余承载力、残余滑移量、抗剪刚度及延性系数的退化规律;最后,基于疲劳累积损伤理论和材料剩余强度模型,确定新型螺栓连接件在疲劳加载过程中的损伤度,进而建立新型螺栓连接件的剩余承载力计算模型。结果表明:新型螺栓连接件在静力和疲劳作用下呈现不同的变形及断面破坏特征;在疲劳荷载作用下,新型螺栓连接件的各项力学性能均呈现不可逆的退化,在该试验中试件在疲劳加载270万次后剩余承载力退化12.1%,延性系数退化67.6%,抗剪刚度退化12.9%,退化较为明显;建立的新型螺栓连接件剩余承载力计算模型计算结果与试验值吻合良好。Here, to adapt to development of fabricated composite beams, a new type stainless steel detachable bolt connector was developed, and its mechanical property degradation laws under fatigue load were studied. Firstly, through literature and market investigation, full considering advantages and disadvantages of existing bolts, a new type stainless steel detachable bolt connector was designed and manufactured to be used for fabricated composite beams. Secondly, 6 groups of push out specimens of new bolt connectors were made for static load and fatigue tests, and failure patterns of specimens after static load and different fatigue loading times were compared, and analyses were focused on degradation laws of residual load-bearing capacity, residual slip, shear stiffness and ductility coefficient of new bolt connectors in fatigue loading process. Finally, based on the fatigue cumulative damage theory and material residual strength model, the damage degree of new bolt connectors in fatigue loading process was determined, and further the residual load-bearing capacity calculation model of new bolt connectors was established. The results showed that under static and fatigue loads, new bolt connectors reveal different deformations and fracture surface failure characteristics;under fatigue load, all mechanical properties of new type bolt connectors reveal irreversible degradation;in tests, after 2.7 million times of fatigue loading, the residual load-bearing capacity of specimens degrades by 12.1%, their ductility coefficient degrades by 67.6%, and their shear stiffness degrades by 12.9%, so their degradation is more obvious;the calculation results obtained using the calculation model for residual load-bearing capacity of new type bolt connectors established here agree well with test values.

关 键 词：不锈钢螺栓连接件 推出试验 疲劳损伤 剩余强度 剩余力学性能 

分 类 号：U448.38[建筑科学—桥梁与隧道工程]