【作者】 查春光；

【导师】 郑山锁；

【作者基本信息】 西安建筑科技大学 ， 防灾减灾工程及防护工程， 2006， 硕士

【摘要】 现今关于型钢混凝土结构的试验研究资料和各国相关规范都明确表明型钢与混凝土之间存在着粘结滑移的问题,并且这种粘结滑移现象对结构受力性能有显著的影响。 本文基于型钢混凝土结构构件受力性能和型钢与混凝土问粘结滑移理论的研究成果,提出了型钢混凝土框架结构杆系模型单目标离散型变量优化设计方法。该优化设计方法中,设计变量取结构构件几何尺寸、截面尺寸、材料强度、型钢截面尺寸,目标函数取型钢混凝土框架结构全部结构材料的造价,约束条件为型钢混凝土组合结构基于粘结滑移的研究结论以及现行设计规程中所规定的合理的设计基本要求、计算要点和构造措施。 优化设计的基本思路是,首先根据工程经验初步确定结构布局、构件几何与截面尺寸、材料强度,并采用有限单元法按杆系模型对框架结构进行不同载荷工况下的内力分析;然后将结构离散为梁、柱构件,根据各载荷工况下构件几何尺寸及相应的内力分析结果,进行结构构件各设计变量的分部优化。在分部优化中采用求解离散变量的混合惩罚函数法进行优化设计,优化计算的初期主要按连续变量进行计算,随着迭代进行,变量的离散性很快起控制作用,最后收敛到指定的离散值;修改构件的设计变量,并将其重新整合得新的结构方案。重复上述迭代过程,直至获得结构构件各设计变量的最佳取值。最后,结合实例计算并与原始方案进行经济效益对比分析,提出各主要设计参数的最佳取值。 本研究为型钢混凝土框架结构的优化设计提供了实用方法与途径,其不仅符合于工程实际,且能够体现规范的要求,为其它型钢混凝土结构以及钢与混凝土组合结构的优化设计提供借鉴。更多还原

【Abstract】 At present, the experimental researches and many national specifications concerning the steel reinforced concrete (SRC) composite structures always indicate that there are bond-slip behaviors between shaped steel and surrounding concrete. And the bond-slip behaviors have great influence on the load-bearing capacities of SRC structures.Based on the experimental results of bond-slip behaviors between encased steel and concrete and the design requirements for SRC structures, an optimal design scheme of single objective and discrete variables is proposed to design SRC frame structures. In the optimum scheme, the design variables include the layout dimensions of SRC frame structure, structural member sections, the strengths of concrete and steel, the dimensions of steel shapes;the objective function is the cost of the entire materials applied to construct a SRC frame structure;the constraint conditions are main requirements stated in Chinese code for design of SRC structures, which are basic design rules, reasonable calculating theories, indispensable constructions, and some mature requirements and conclusions confirmed by experimental studies on the calculating methods of SRC structures following the bond-slip theory between steel shape and concrete encasement.The outline of the optimal design scheme is as follows: Firstly, the geometric layout of structure, geometric dimensions and cross sectional sizes of structural members as well as material strengths are specified in advance according to the conceptual design and considerable experience drawn from some civil engineering projects. And then, the frame element model of the SRC frame structure is analyzed under all possible loads. The internal forces, including bending moments, axial forces and shear forces, are obtained by finite element method. And the geometric dimensions and cross sectional sizes of structural members can be determined optimally to some extent by conceptual design. Secondly, the SRC frame structure is divided into structural elements of columns and beams. The structural members have initialgeometric sizes and are subject to obtained internal forces and given behavioral and technological constraints. They are analyzed and optimized in partitioned segments in response to the design variables and the cross sectional dimensions are to be optimally chosen further. In the optimization of structural members, the design variables are determined by the SUMT method with discrete design variables. In the early stage, the optimal calculation is done with the method of continuous design variables. With the progress of the iterative computations, the control action of the discreteness of the design variables appeared rapidly until the design variables convergence to the specified discrete value. After the design variables of structural members are corrected, a new structure scheme can be obtained with the new design variables. The steps of the above will be repeated, and the optimal choice of the design variables of structural elements and structure can be obtained. Finally, a number of existing SRC structural projects are checked with the optimal design method of single objective and discrete variables. There is a sharp contrast in the economic effect between optimal design method and the initial design scheme. Moreover, the optimal values of the main design parameters are proposed. All these may contribute to the analysis and design improvement of SRC frame structures and provide a practical method satisfying civil engineering practice and requirements stated in the Codes.更多还原