混合梁斜拉桥钢-混结合段受力行为仿真分析

Numerical Simulation Analysis of Steel-Concrete Joint Section in Hybrid Girder of Cable-Stayed Bridge

为探讨混合梁斜拉桥钢-混结合段的受力行为,以黑瞎子岛乌苏大桥为研究对象,采用通用有限元程序ANSYS,对其钢-混结合段的受力行为进行了非线性数值仿真分析.分析中考虑了结构和材料的非线性特性,采用非线性弹簧模拟栓钉的粘结-滑移行为,并与采用线性弹簧模型的分析结果进行了比较.计算结果表明:采用非线性弹簧单元模拟栓钉时,数值分析结果与试验结果吻合较好;在设计荷载作用下,采用线性栓钉模型和非线性栓钉模型的计算结果差别不大;采用不同的栓钉力学模型时,对结合段混凝土的初始裂纹扩展模式有较大影响,而混凝土大部分开裂后裂缝分布的差异不大.

To investigate the mechanical behavior of steel-concrete joint section of cable-stayed bridge,ANSYS,a general finite element package,was used to analyze the nonlinear numerical simulation of the joint section mechanics behavior of Wusu bridge in Heixiazi Island. In the analysis, the nonlinear characters of structure and material were taken into account,and nonlinear spring elements were employed to simulate the bond-slip effect of studs. The analysis results based on nonlinear spring elements were compared with the ones obtained using linear spring elements. The numerical analysis results show that as studs are simulated by nonlinear spring elements,numerical results agree well with the model test ones. The linear and nonlinear stud models make little difference between the calculation results under the design load. Different stud mechanics models will induce a significant effect on the initial propagation pattern of cracks in the concrete of joint section,while there exist a few difference about the distribution of crack after most cracks happen.