Authors:
Delei Yang; Lewei Tong;
Abstract:
Fatigue behavior of welded joints is studied using hot spot stress method. In this case, the hot spot stress calculation method must be given. This paper dealt with hot spot stress of CHS-CFSHS T-joints made up of circular hollow section (CHS) braces and concrete-filled square hollow section (CFSHS) chords. Seven finite element models were established to calculate and analyze extrapolation region, extrapolation methods, strain concentration factors (SNCFs) and other related aspects of hot spot stress when braces were under axial tension. The paper examined the accuracy of the finite element calculation model and the reliability of the calculated results and clearly defined the calculation method of hot spot stress of CHS-CFSHS welded joints. Research showed that the finite element calculation method and model presented in the paper could accurately calculate
SNCFs of CHS-CFSHS T-jonits. The extrapolation method to determine SNCFs had clear physical meanings and desirable results; the extrapolation region of pure SHS joints can be used as the extrapolation region of CHS-CFSHS joints for calculating SNCFs. SNCF numerical values obtained by quadratic extrapolation should be the result of finite element calculation of SNCFs of CHS-CFSHS joints.
Keywords:
CHS-CFSHS welded joints, Strain concentration factors (SNCFs), Hot spot stress calculation, Finite element analysis, Extrapolation methods