(1 中国地震局工程力学研究所, 哈尔滨 150080; 2 中国地震局地震工程与工程振动重点实验室,哈尔滨 150080; 3 辽宁科技大学土木工程学院, 鞍山 114051)

摘要: 以混凝土强度、截面宽厚比和是否填充混凝土为参数,进行了 5 个冷弯方钢管混凝土试件和 1 个冷弯方钢管试件的轴心受拉性能试验。 使用 ABAQUS 软件对试件进行了有限元模拟,模拟的荷载-应变曲线与试验结果吻合较好。 对混凝土的开裂点、钢管与混凝土的拉力分配、承载力的提高程度和工作机理等方面进行了研究。 结果表明:随宽厚比的增大,试件的断裂应变呈减小的趋势;试件破坏位置集中在跨中和距加载端 1 / 3 试件高度处,断面呈水平方向或与中截面呈 45°;在试件中截面测点的纵向应变为 150με 左右时,核心混凝土开裂,试件刚度出现折减;宽厚比在 15 ~ 240 的范围内,混凝土的填充对钢管的轴拉承载力提高幅度在 3. 03% ~ 30. 75%。 基于参数分析拟合出了冷弯方钢管混凝土的轴拉承载力公式。

关键词: 冷弯方钢管混凝土; 轴心受拉; 承载力; 宽厚比; 有限元模拟; 工作机理

中图分类号:TU398. 9 文献标志码:A 文章编号:1002-848X(2022)13-0086-08

DOI:10. 19701 / j. jzjg. 20210800

Study on mechanical properties of cold-formed concrete-filled square steel tube under axial tension

GAO Huaguo1,2,3, ZHANG Lingxin1,2, JIAO Chenxing3, WANG Qingli3

(1 Institute of Engineering Mechanics, China Earthquake Administration, Harbin 150080, China; 2 Key Laboratory of Earthquake Engineering and Engineering Vibration, China Earthquake Administration, Harbin 150080, China; 3 College of Civil Engineering, Liaoning University of Science and Technology, Anshan 114051, China)

Abstract: Taking concrete strength, cross-section width-thickness ratio and concrete filling or not as parameters, five cold-formed concrete-filled square steel tube specimens and one cold-formed square steel pipe specimen were tested in axial tension. The finite element simulation of the specimens was carried out using ABAQUS software, and the simulated load-strain curve was in good agreement with the test results. The cracking point of concrete, the distribution of tensile force between steel tube and concrete, the improvement degree of bearing capacity and working mechanism were studied. The results show that with the increase of the width-thickness ratio, the fracture strain of the specimen shows a decreasing trend; the failure position of the specimen is concentrated in the middle of the span and 1 / 3 of the height of the specimen from the loading end, and the section is in the horizontal direction or at 45° to the mid-section; when the longitudinal micro-strain of the cross-section measurement point in the specimen is about 150με , the core concrete cracks and the stiffness of the specimen is reduced; the width-thickness ratio is in the range of 15 ~ 240, and the filling of concrete affects the axial tension of the steel pipe, the increase in bearing capacity is 3. 03% ~ 30. 75%. Based on the parameter analysis, the formula for the axial tensile bearing capacity of the cold-formed concrete filled square steel tube was fitted.

Keywords:cold-formed concrete-filled square steel tube; axial tension; bearing capacity; width-thickness ratio; finite element simulation; working mechanism