Study On Optimal Design Method Of SRC Frame Structures Based On Theory Of Bond-Slip

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 mechanical performance of SRC structures.Based on the experimental results of bond-slip behaviors between shaped steel and concrete and mechanical behaviors of SRC structures, the optimum method of the nonlinear finite element full-range analysis of SRC frame structures is proposed. In the optimum scheme, the design variables include the layout dimensions of SRC frame structure, structural member sections, the strengths of concrete and steel and the section dimensions of shaped steel; the objective function is the cost of the entire materials applied to a SRC frame structure; the constraint conditions are main requirements stated in Chinese code for design of SRC structures, which are basic design rules, indispensable construction measures, and some mature requirements and conclusions confirmed by experimental studies on the calculating methods of SRC structures following the bond-slip theory between shaped steel and concrete.The outline of the optimal design scheme is as follows: Based on the nonlinear finite element full-range analysis of SRC frame structures, an optimization design of frames which fully consider the nonlinear feature of SRC structure is proposed for the least cost of project. Firstly establish parameterization model of SRC composite frames by ANSYS to carry through nonlinear finite element analysis, and then extract optimization design parameters for forming optimization analysis file, at last enter optimization analysis module and accomplish optimization iteration. The entire procession not only can imitate the phenomenon of crack development, reinforcement yielding, concrete crushing and internal force redistribution but also nonlinear analysis and system optimization are jointed together, iterated and converged mutually in nonlinear finite element optimization program, which in effect reduces the times of the iteration. Finally, 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.