Study On Initial Rotation Stiffness Of Space Joints With End-Plate Connection Based On The Component Method

Node is an important part of the overall structure so that the performance analysis of joint has become an indispensable part of the structure design. Conventional structure design usually presumes that joints are either fully rigid or ideally pinned,but this ignores the real performance of the joint.In practice,joints can transfer the shear and pass some bending moments,and exhibit a mechanical behaviour between the case of fully rigid and ideally pinned.Therefore, the concept of semi-rigid joint is put forward and researched,which makes the joint research more specific through the study of moment-rotation curves containing initial rotation stiffness, bending moment capacity and rotation capacity of the joint. However,the research for joints is primarily focused on the plane form,not being close to the real shape of the joint and there is still a gap to obtain the real property of the joint. Therefore,space joint being more close to the real form of the joint is under study.This paper adopts a progressive structure to study space steel joints and the specific work is as follows(1) Based on the perspective of how to accurately reflect the real performance of the joint,this paper adopts a new classification way to summarize and review on the researches of end-plate connection at home and abroad and highlights the lack of study on space joints.(2) Experiments were made to study the behavoir of strong axes and weak axes connections and compared with numerical simulation results to verify the validity of the proposed model.For the first time three kinds of finite element models of space steel joints were established to analyze the influence of different loading cases and the performance difference with planar joint.It can be seen that there are different level of effects between strong axes and weak axes for space joints,especially for space corner joints, while the initial rotational stiffness and load capacity of space joint are significantly greater than those of planar joint.(3) Founded on the idea of component method, each component stiffness of the first class and second class space end-plate connections was redesigned innovatively. New formulas for calculating initial rotation stiffness of the space joint were put forward and were in good agreement with the results of finite element analysis,which proved that the theoretical calculation formulas were desirable.