Reference Type: Journal Article Record Number: 1 Author: Gu, M., Tong, L.W., Zhao , X. L. and Zhang, Y. F. Year: 2014 Title: Numerical analysis of fatigue behavior of welded cfchs t-joints Journal: Advanced Steel Construction Volume: 10 Issue: 4 Pages: 22 Start Page: 476 Short Title: Numerical analysis of fatigue behavior of welded cfchs t-joints DOI: 10.18057/IJASC.2014.10.4.7 Keywords: Concrete-filled circular hollow section, Welded joints, Fatigue life prediction, Fracture mechanics, Finite element analysis  Abstract: Fatigue life assessment of welded joints made of circular hollo w sections (CHS) with concrete filled (CF) chord member subject to vehicle load is vital in designing of CFCHS arch truss bridge. A key issue in fatigue life assessment of such joints is how to accurately estimate the stress intensity factor. This paper describes a methodology for calculating the stress intensity factor of the hot spot region in the welded CFCHS T-joints based on a finite element analysis which considers weld modeling, crack modeling and nonlinear interface element between steel and concrete. A procedure for fatigue life estimation of welded CFCHS T-joints is also established. Discussions are made on the effect of the initial crack size and concrete strength on fatigue life and hot spot stresses. The majority of crack propagation life is found to be associated with the shallow crack stage. The proposed method gives reasonable estimation of fatigue life of welded CFCHS T-joints. Author Address: State key laboratory for Disaster Reduction in Civil Engineering, Tongji University and College of Civil Engineering, Tongji University, Shanghai 200092, China