真实侵蚀路径下焊钉锈蚀过程及承载能力演化特性

Corrosion Process and Bearing Capacity Evolution Characteristics of Welding Studs Under Real Corrosion Path

摘要:

通过6个焊钉连接件的氯盐侵蚀退化试验及推出试验，探究钢板组合梁焊钉连接件锈蚀后的静力性能。模拟桥面除冰盐环境下“环境―混凝土―钉头”氯盐侵蚀路径，试验完成后焊钉三维扫描重建结果表明，焊钉钉头部位锈蚀最严重，钉身部位锈蚀相对较轻。基于焊钉三维扫描重建的有限元模拟和试验结果揭示，在“环境―混凝土―钉头”侵蚀路径下，随着焊钉锈蚀程度的加深，连接件的承载性能、极限滑移和整体刚度均逐渐降低。根据试验结果拟合得到了考虑焊钉钉头和钉身锈蚀率的连接件抗剪承载力修正公式及连接件荷载?滑移曲线计算公式。从公式可以看出，相较于钉头部位，钉身部位的锈蚀更易引起连接件抗剪性能的降低。

Abstract:

This paper presents the static property of steel plate composite beam welded connections after corrosion degradation caused by chloride salt exposure. The degradation test involves the use of six studs， and the results of the test are used to explore the effects of rust on connections’ mechanical properties. The chloride salt corrosion path of environment-concrete-stud head in a bridge deicing salt environment is simulated. After the test is completed， the three-dimensional scanning reconstruction of studs shows that the stud heads are the most severely corroded， while the corrosion on stud shafts is relatively mild. The finite element simulation based on the three-dimensional scanning reconstruction of studs and experimental results reveal that as the degree of stud rust increases along the environment-concrete-stud head corrosion path， the connection’s bearing capacity， ultimate slip， and overall stiffness gradually decrease. According to test results， a corrected formula for the shear bearing capacity of the connection and a corrected formula for the load-slip curve of the connection， considering the rust rates of stud heads and stud shafts， are derived. The formulas show that compared with stud heads， the rust on stud shafts is more likely to cause a reduction in the connection’s shear resistance.