预应力混凝土组合箱梁桥波形钢腹板优化分析

Optimization Analysis of Corrugated Steel Webs of Prestressed Concrete Composite Box-girder Bridge

建立3种不同体系的波形钢腹板预应力混凝土组合箱梁桥空间有限元计算模型,采用AN-SYS参数化语言对钢腹板进行多约束条件下多设计参数的优化计算分析,寻求各设计参数的最佳组合规律.结果表明,随着循环次数的增加,目标函数趋于理想值,而设计变量及状态变量也趋于稳定,但目标函数值并非是最终取值时惟一考虑的因素,优化结果将提供多组满足约束条件的设计参数;波形钢腹板剪切屈曲应力的理论计算值偏于保守;钢腹板的厚度在通常范围内偏小;在已有资料范围内,波形钢腹板折叠角度及腹板与竖直面的夹角偏小,而波形钢腹板折痕间的长度则偏大.

For exploring the optimum composite regularity of design parameters,the optimal analysis of corrugated steel webs with multi-restraint condition and multi-variable was done by establishing the 3D finite element models of three PC composite box-girder bridge types with corrugated steel webs,based on the APDL parametric language.The results indicate that the objective function tend to ideal value,and the same time design variables and state variables tend to be stable with the increase of the cycle number,but the objective function value is not the only consideration of the ultimate design parameters to use,the optimal results will provide some groups of design parameters meeted restraint conditions.Theory calculating value of shear buckling stress of corrugated steel web is conservative;steel web thickness tends to be small in usual ranges.Thicker web is not optimal design.In existing parameter ranges,the corrugation angle and the angle of web to vertical plane tend to be small,but the length of folded marks of corrugation tends to be large.