Analysis On Ultimate Bearing Capacity Of Steel Gusset Joints

The structural form of Steel gusset joints was originally introduced by TEMCOR company,which is initially applied to the alloy space grid structures.Later on,it was also applied to the steel structures because of its many advantages such as simple structure type,without welding,nice appearance,easy to assemble.There are few studies on ultimate bearing capacity of steel gusset joints at domestic and foreign,and there is no calculation method of practical bearing capacity of gusset joints,and no certain basis for engineering design.However,the performance of joints would significantly influence the deformation of the structures and the internal force of the member.Therefore,it is necessary to study the mechanical properties and bearing capacity of steel gusset joints.In this paper,the steel cover joints are systematically studied through both experiment and finite element numerical simulation,and the formula of bearing capacity of steel gusset joints under different load conditions is presented.This paper begins with the introduction of the common joints form of the space grid structure,expatiates the joint form and application of the steel cover node,and summarizes the research status of the steel gusset joints,expounds the shortcomings of the current research and the meaning of further studies on the gusset joints.In order to investigate the load bearing capacity of steel gusset joints,a full scale test of steel gusset joints is carried out.In this paper,the specimen size,test loading device,measuring point layout and other test preparation was fully presented.the corresponding relationship between stress and load is achieved according to the test results.On the basis of this,the finite element software ANSYS is used to simulate the steel gusset joints for further study.The nonlinear stress-strain relationship and the Von-Mises yield criterion are used in the analysis.The model also considering the influence of geometrical nonlinearity as well as the contact between the gussets,bolts and rods.Beside and also use the preload function to simulate the preload of the bolt.By the researches on the stresses and deformation of the joints,structural behavior and the collapse mechanism are investigated for the steel gusset joints subject to various loading.The load-displacement curve,load-strain curve and contrast test result are obtained to verify the accuracy of the finite element model analysis.It reveals that the results of numeric models fit well with those specimens.Based on the finite element model,the mechanical properties of the gusset joints under different stress states are numerically analyzed.Then,the failure modes and the development of internal forces of the steel gusset joints under different stress states are studied.Finally,combining the theoretical analysis and domestic and foreign codes,bearing capacity formulas are proposed for ultimate load-bearing capacity subject to different loading.The results from this study can be used for practical engineering design,and also for reference when the relevant codes are revised.