Parametrized Optimization And Program Development On Energy Dissipation Of NPTED-included Prefabricated Concrete Frames

The fabricated concrete frame structure with dry connection has a high degree of industrialization and meets the sustainable development requirements and future development trend of the construction industry.However,the weak performance of dry connection may cause the reliability of the structure to decline or even collapse under strong earthquakes.Therefore,the application of damping device to fabricated frame joints is a common idea in the design of fabricated structures at present.However,the new energy dissipation and damping joints can not be directly used in the structure,not only because the overall seismic performance of the structure is affected by the joints,but also the cost of the new joints is usually relatively high.It is very necessary to optimize the joint damping device of the fabricated structure to obtain a safe and reliable new joint combined with the cost and seismic performance.In this paper,the new RDF joint damper and its new NPTED joint form proposed by the research group are applied to the prefabricated concrete frame.Focusing on the seismic optimization of the prefabricated concrete energy dissipation and damping frame,the seismic finite element program D-SAP of large-scale structure is continuously developed and its simulation and analysis function is improved;Combining Grasshopper parametric modeling with structural optimization design,a new and efficient optimization design process and tool are proposed;Finally,the size of prefabricated components of prefabricated concrete energy dissipation and damping frame structure and the collaborative optimization design of new energy dissipation and damping joints under different fortification levels are realized.The main contents of this paper are as follows:(1)Continuous development of elastoplastic finite element program D-SAP.In terms of material analysis,for the hysteretic curve of NPTED energy dissipation and damping node,six skeleton shape control parameters are proposed and divided into nine different stress state segments,so as to formulate the hysteretic rules suitable for the judgment of material stress state in the program,so as to complete the integration of NPTED energy dissipation and damping node simulation material SMA in D-SAP;In terms of analysis algorithm,based on the existing static pushover analysis algorithm,combined with the performance design idea in FEMA 356,bilinear equivalence of the pushover curve is obtained,and the target displacement corresponding to the performance is obtained,so as to complete the integration of the static pushover analysis algorithm of the displacement influence coefficient method in D-SAP.(2)Parametric structural optimization design process and tool development.In view of the current situation that the structural optimization design involves multi-objective performance and cost,the selection and demonstration of the multi-objective optimization problem solving model,and the process and operation of the classical NSGA-II algorithm are improved based on the needs of the actual project to improve the optimization efficiency;Based on the secondary development tool D-SAP API of the research group,the modeling parameterization and visualization of prefabricated PC frame structure with NPTED energy dissipation and damping nodes are realized by supplementing the Grasshopper modeling battery plug-in;The improved NSGA-II optimization algorithm,structural modeling parameterization and finite element analysis are connected through technical means to establish a visual parameterized structural optimization design process and window tool.(3)Seismic optimization of prefabricated PC frame structure with NPTED joints.According to the structure and NPTED node characteristics,the optimization parameters are demonstrated,selected and processed,and the types,value range and methods of four types of optimization parameters are determined;Combined with the calculation process of structural cost,damage energy consumption ratio and seismic performance and the specified requirements for structural performance,joint performance and material performance,the multi-objective optimization formula of the structure under large and small earthquakes is formulated;Finally,the parametric visual structural optimization design tool is used to optimize the case prefabricated PC frame structure,realize the seismic collaborative optimization design based on different fortification levels,and optimize the size of prefabricated components and energy dissipation node parameters.