The Study On The Dynamic Response Of Long Span Prestressed Ribbed Composite Beam Floor System

Large-span prestressed reinforced type composite floor system is a new type of floor system based on composite beams and prestressed structure theory.This type of floor system use steel tube as skeleton,can effectively reduce the dosage of steel,prestress the composite floor system,reduce the cross-sectional dimension,decrease floor weight,can better adapt to large span construction and bearing.make full use of combination materials' physical and mechanical property to lay the foundation for the promotion.Based on the theoretical analysis and numerical simulation,the main contents are as follows:research the tension control force of the large-span prestressed composite beam based on the load balance method,and the structural analysis parameters are established,which lays the foundation for the dynamic response analysis;Based on the basic principle of the quasi-plate method,the dynamic response formula of the ribbed floor is deduced,the dynamic response of the structure is studied,and the dynamic response eigenvalues of the floor are determined.Based on the large-scale finite element analysis software ANSYS,the dynamic characteristics of the floor are analyzed.The parameters are discussed by changing the eccentricity(ie,the position of the prestressing tendon),the floor thickness and the height of the ribs.The finite element results and the theoretical results are compared and analyzed.Based on the simplified finite element model,by using the time-history method,researched the the influence of the presence or absence of prestressed steel truss on the dynamic response of the floor,and the response of the prestressed arrangement to the floor dynamic response of the building.The results show that the composite floor has good bearing performance and shock resistance,the comfort also meet the daily requirements.The height of the ribs has a great influence on the base frequency of the floor,and the position of the prestressed tendons has obvious influence on the dynamic response of the floor.Therefore,it should be considered in the structural design.