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基于正交试验的钢桁-混凝土组合梁优化设计
Optimal design of steel truss-concrete composite beams based on orthogonal experiment
【摘要】 为加快绿色交通建设,降低钢桁架结构桥梁建造中的碳排放,实现钢桁-混凝土组合梁结构快速经济合理的设计,提出同时考虑结构位移、构件应力和建材用量的整体结构多目标优化设计方法。以经济效益和结构整体性能提升为目标函数,以钢桁-混凝土组合梁中各构件设计参数为设计变量,结合钢桁-混凝土组合梁挠度和材料强度等约束条件,构建钢桁-混凝土组合梁多目标优化设计数学模型。选取钢桁架竖向高度、纵向节间长度、弦杆截面宽度和高度、斜腹杆截面宽度和高度以及桥面板厚度关键设计参数,分析整体结构主要截面挠度和关键构件最大应力对关键设计参数变化的敏感性。以敏感性分析结果为基础,选取关键设计参数作为正交试验因素,设计32组正交试验。提出钢桁-混凝土组合梁层次分析优化评定系数计算方法,并对32组正交试验结果进行评定,确定设计参数对优化评定系数影响的主次顺序,明确钢桁-混凝土组合梁设计中结构性能与经济效益之间的关联规律,获得其最优设计参数组合。研究结果表明:优化后结构钢材质量为976.03 t,与优化前相比节省用钢质量约5.1%,结构竖向挠度降幅约11.38%,杆件应力最大降幅为14.09%。基于正交试验的结构优化设计方法适用于钢桁-混凝土组合梁结构多目标优化设计,可助力国家“双碳”战略目标的实现。
【Abstract】 In order to accelerate the construction of green transportation, reduce the carbon emission in the construction of steel truss structure bridge, and implement the rapid, economical and reasonable design of steel truss-concrete composite beam structure, a multi-objective optimization design method for the whole structure was proposed which considers structural displacement, component stress and building material consumption. With economic benefits and overall structural performance improvement as objective functions, design parameters of each component in steel truss-concrete composite beams as design variables, combined with constraints such as deflection of steel truss-concrete composite beams and material strength, a multi-objective optimal design mathematical model of steel truss-concrete composite beams was established. The key design parameters, such as the vertical height of steel truss, the longitudinal panel length of steel truss, the width of chord section, the height of chord section, the width of diagonal section, the height of diagonal section and the thickness of bridge deck, were selected to analyze the sensitivity of the main section deflection of the whole structure and the maximum stress of key components to the change of key design parameters. Based on the results of sensitivity analysis, 32 groups of orthogonal experiments were designed by selecting key design parameters as orthogonal experimental factors. The calculation method of the optimization and evaluation coefficient of steel truss-concrete composite beam was put forward, and 32 groups of orthogonal test results were evaluated, the main and secondary order of the influence of design parameters on the optimization and evaluation coefficient was determined, the correlation law between structural performance and economic benefit in the design of steel truss-concrete composite beam was clarified, and the optimal design parameter combination of steel truss-concrete composite beam was obtained. The results show that the optimized structural steel dosage is 976.03 t, which saves about 5.1% compared with that before optimization, the vertical deflection of the structure decreases about 11.38%, and the maximum stress reduction of the member is 14.09%. The structural optimization design method based on orthogonal test is suitable for the multi-objective optimization design of steel truss-concrete composite beam structure, and can help realize the national ‘double carbon’ strategic goal. 7 tabs, 9 figs, 28 refs.
【Key words】 bridge engineering; steel truss-concrete composite girder; orthogonal text; structure performance; sensitivity analysis; optimization design method;
- 【文献出处】 长安大学学报(自然科学版) ,Journal of Chang’an University(Natural Science Edition) , 编辑部邮箱 ,2023年06期
- 【分类号】U442.5
- 【下载频次】37