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Research On Hysteretic Performance Of Square Steel Pipe Truss K Type Prefabricated Local Concrete Reinforced Joints

Posted on:2020-10-05Degree:MasterType:Thesis
Country:ChinaCandidate:L F YangFull Text:PDF
GTID:2392330590987259Subject:Architecture and civil engineering
Abstract/Summary:PDF Full Text Request
Steel tube truss structure is one of the main forms of space structure.With the continuous development of social economy and architectural structure and the diversification of architectural functional requirements,the scale of such structures tends to be large,heavy and complicated.The intersecting joints of steel tubes are often the weak parts of structures because of the obvious stress concentration and the confluence of the rods.In order to meet the requirements of operation,it is usually necessary to strengthen the tubular joint.Based on the previous studies on the strengthening measures of intersecting joints,and aiming at the common K-joints basic joint forms of spatial long-span steel tube structures,this paper proposes to precast locally filled concrete prefabricated strengthening joints in the factory and then assemble the structure in the site.This new type of assembled node has the advantages of reducing the dead weight of structure,optimizing the failure mode of the node,facilitating the replacement,and realizing the rapid recovery after the disaster.At the same time,it can solve the problem of insufficient bearing capacity of key joints of long-span steel tube structure.In this paper,nonlinear finite element method is used to study the hysteretic behavior of the new type of joints under reciprocating load.At the same time,this kind of node is placed in the truss to further explore the influence of local node changes on the hysteretic performance of the structure.The details are as follows:(1)For the K-joints joints commonly used in truss structure,two joint construction forms are proposed according to the strengthened joints of partial filled concrete,and considering the nodes as independent parts to realize factory processing,on-site assembly and component assembly.(2)By using the nonlinear finite element method and the comparison with the existing test method,the refined model of K-joints joints was constructed to analyze the failure mode and hysteretic performance of two new assembled strengthened joints under the action of reciprocating load.The research shows that all the new K-joints joints can change the original failure mode of K-joints intersecting joints,and effectively achieve plastic hinge outward displacement.At the same time,the bearing capacity,ductility and energy dissipation capacity of the new K-joints joints are improved compared with the traditional intersecting joints.(3)A new K-joints joint was selected to carry out numerical simulation under reciprocating load for the parameters such as the gap between two pipes,the strength of concrete filled in and the ratio of pipe diameter to thickness.By analyzing its bearing capacity,hysteretic curve,energy dissipation coefficient and other indicators,the influence law of parameter change on the hysteretic performance of the new type of assembled strengthened joints and the design Suggestions are obtained.(4)The selected new nodes were placed in the Warren truss to analyze the failure modes and dynamic performance of strengthened nodal Warren truss and traditional Warren truss under the action of reciprocating load.The study shows that compared with the traditional truss,the strengthened joint truss can change its failure mode and realize plastic hinge outward displacement.At the same time,its bearing capacity,initial stiffness,ductility and energy dissipation capacity are improved.
Keywords/Search Tags:K-joints, Partially filled concrete, Fabricated connections, Numerical analysis, Hysteretic performance
PDF Full Text Request
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