避雷针构架结构端板连接高强螺栓常幅疲劳性能试验研究  

Experimental study on constant amplitude fatigue of high-strength bolts of end-plate connection of lightning rod structures

作　　者：刘勇[1] 魏珍中[1] 张继亮 雷宏刚[2] 焦晋峰[2] LIU Yong;WEI Zhen-zhong;ZHANG Ji-liang;LEI Hong-gang;JIAO Jin-feng(Shandong Electric Power Engineering Consulting Institute Co.,Ltd,Jinan 250013,China;Collegeof Ciuil Engineering,Taiyuan Uniuersity of Technology,Taiyuan 030024,China)

机构地区：[1]山东电力工程咨询院有限公司,山东济南250013 [2]太原理工大学土木工程学院,山西太原030024

出　　处：《空间结构》2022年第2期79-86,共8页Spatial Structures

基　　金：国家自然科学基金项目(51578357);山西省留学人员科技活动择优资助项目(DC1900000602);山西省应用基础研究项目(201801D221216)。

摘　　要：为研究避雷针构架结构端板连接处高强螺栓的疲劳性能,对材质为35K的8.8级M24高强螺栓进行了3个试件的静力拉伸试验和15个试件(应力比为0.5)的“轴心拉-拉”常幅疲劳试验.拟合了应力-循环次数曲线(即S-N曲线),选取典型试件疲劳断口进行宏观和微观分析,并与《钢结构设计标准》中疲劳相关条文进行了对比分析.结果表明:疲劳试验数据整体较为离散,但均在95%置信区间内;拟合的S-N曲线基本反映不同应力幅下试件的疲劳寿命;试件缺口效应明显.尤其在螺栓螺纹齿根处,应力集中程度严重,点状疲劳源易扩展形成线状疲劳源,断口韧窝特征明显.对比试验结果和标准建议公式计算结果,2×10;次循环次数对应疲劳强度为标准建议值的1.71倍.In order to study the constant-amplitude fatigue performance of grade 8.8 high-strength bolts of end-plate connection in lightning rod structures under axial tension-tension condition, 3 static tensile tests and 15 constant-amplitude fatigue tests(stress ratio of 0.5) were carried out on M24 bolts made of 35 K steel. Stress-number(S-N) curves were fitted and the fatigue fracture surfaces of typical specimens were analyzed macroscopically and microscopically. In addition, all the test results were compared with the relevant fatigue provisions of Standard for Design of Steel Structures. The conclusions are as follows. The fatigue test data are generally discrete, but all are within the 95% confidence interval. The S-N curves basically reflect the fatigue life of specimens under different stress amplitudes. The notch effect of the specimens is evident, and the stress concentration is especially serious at the root of the screw thread. The punctiform fatigue source tends to expand to linear fatigue source, and the dimples are obvious. The test results were compared with the results obtained by recommended formula in the national standards, and the corresponding fatigue strength of 2×10~6 times was 1.71 times that of the recommended value.

关 键 词：避雷针构架 高强螺栓 常幅疲劳 疲劳断口 S-N曲线 

分 类 号：TU392.3[建筑科学—结构工程]