The Study On Residual Stress Of K-Type CHS Joints

K-joint was adopted in steel truss usually. One of the main contents of design wasanalysis of joint. Connection method of truss structure was welding of intersection.Because of producing a high temperature with welding process, lead to produce largerresidual stress in joint. By the influence of the residual stress, it would decrease thebearing capacity of K-joint. At last, the study of joint ignored the residual stress.Inorder to get a more accurate stress analysis of joint, it is necessary to analyzed residualstress.This paper would study residual stress of K-joint.The K-joint was studied by numerical simulation using birth and death finiteelements in ANSYS to simulate welding process. The life and death elements wasapplied through welding temperature. K-joint contains two welds which were dividedinto24segments. Through the finite element numerical method, we got the welding ofthe temperature and stress. Of the residual stress model loading and solving, get thebearing capacity of K-joint. We know that residual stress influenced the bearingcapacity of K-joint.In this paper the main work was as follows:①Finite element model of K-joint was established. It contained element selection,accurate and rational grid, considering the physical and mechanical properties withtemperature.②With analysis to the results of the welding temperature different time anddifferent position with changing of temperature were compared to get the weldingtemperature distribution and the trend of changing with time.③With analysis to the results of residual stress, geometrical parameters effectresidual stress, residual stress changes in welding process, and obtain the law of finalresidual stress.④Through the displacement loading method load to contain and do not containwelding residual stress of the finite element model, obtain load-displacement curve ofdifferent parameter K-joint (with a total of24).⑤The bearing capacity of K-joint including welding residual stress and withoutwelding residual stress were calculated. The different bearing capacity of K-joint whichwas influenced by residual stress and obtained by standard formula were compared. This paper calculates24joints of different parameters, and concludes that the residualstress influence the bearing capacity of K-joint.