Mechanical Performance Analysis Of New Total-prefabricated Steel Structure Floor System

Prefabricated steel structure building has the advantages of convenient construction,excellent seismic resistance and green energy saving,which has become the key development target for advancing the supply side structural reform of the construction industry.As the key to the development of prefabricated steel structure buildings,the floor system generally adopts the non-supported floor system with higher degree of assembly.However,the commonly used prefabricated floor system only realizes partial assembly,and there are still many wet operations on the site.And the design standards and construction standards are not perfect.In order to meet the development needs of prefabricated steel structure buildings,a new type of total-prefabricated steel structure floor(TSSF)system matching with steel structure buildings is proposed in this paper.Through the corresponding theoretical calculation and finite element simulation,the mechanical performance of the system is analyzed.The main work of this paper is as follows:(1)A new type of total-prefabricated steel structure floor(TSSF)system is designed and developed,which mainly includes three kinds of PTB,supporting PTL,beam-plate connection,primary and secondary beam connection,and connection mode between plates.(2)Six finite element models were established to study the flexural capacity of three kinds of PTB under different boundary conditions.The results show that the ultimate bearing capacity of the three types of plates PTB60-310-930,PTB80-330-660 and PTB110-366-732under simple support is 5.12k N/m~2–7.13k N/m~2,which is 1.12–1.47 times of the design load.Under the condition of fixed support,the ultimate bearing capacity is 19.96k N/m~2–26.58k N/m~2,which is 4.37–5.48 times of the design load.(3)The mechanical properties of beam-plate joints of TSSF system were studied by comparing and analyzing the models of beam-plate joints and pure rigid joints of TSSF system.Three series of 20 finite element models were designed to study the influence of PTF thickness,PTB thickness and PTL web thickness on the stiffness of beam-plate joints.The results show that the beam-plate joints of TSSF system are rigid joints;The influence of each variation parameter on the stiffness degree of the joint is arranged from large to small as follows:PTF thickness,PTB thickness and PTL web thickness.(4)The mechanical properties of primary and secondary beam joints of TSSF system are studied by comparing and analyzing the models of primary and secondary beam joints and pure rigid connection joints.A total of 10 finite element models in four series were designed to study the influence of bolt number,sleeve length sleeve thickness and bolt diameter on node performance.The results show that the primary and secondary beam joints of TSSF system are rigid joints;The thickness of sleeve,the number of bolts and the length of sleeve have a great influence on the performance of joints;The bolt diameter has little effect on the joint performance.