双碑嘉陵江大桥非线性稳定分析

为保证双碑嘉陵江大桥结构的安全,对该桥进行非线性稳定分析。采用ANSYS建立全桥有限元模型,考虑梁柱、大位移、斜拉索垂度等几何非线性因素,采用弹塑性分析中的各向同性强化模型考虑材料非线性,材料本构关系选用双折线模型。分析结果表明：该桥的稳定性满足规范要求,考虑几何非线性的结构稳定安全系数和仅考虑线弹性的结构稳定安全系数差别不大;考虑材料非线性的结构稳定安全系数大概是仅考虑线弹性的结构稳定安全系数的0.4倍左右;考虑几何与材料双重非线性的结构稳定安全系数是仅考虑线弹性的结构稳定安全系数的0.3倍左右。建议非线性稳定的安全系数参考结构丧失承载能力的安全系数的计算方法。

Nonlinear Stability Analysis of Shuangbei Jialing River Bridge

To verify the safety of Shuangbei Jialing River Bridge, Non-linear stability analysis was per- formed. The FEA model of the whole bridge was created by ANSYS, considering geometry non-line- arity, such as beam-column effect, large-displacement, and cable-sag effect. And material non-lineari- ty was also taken into account by using bilinear isotropic hardening model. The analysis results show that the buckling factor with consideration of geometry-nonlinearity is close to that of linear analysis. The buckling factor of the non-linear analysis with material-nonlinearity was 0.4 of that of linear anal- ysis. The buckling factor of the non-linear analysis with geometry-nonlinearity and material-nonlinear- ity was 0.3 of that of linear analysis. It is suggested that the calculation method of buckling factor of nonlinear stability can refer to buckling factor of the structure that has losing its bearing capacity.