| Title |
Heat Transfer and Stress Analysis During Multi-Pass Butt-Welding of NG Pipe by FEM |
| Authors |
방인완(In Wan Bang) ; 이용기(Yong Gi Lee) ; 김우식(Woo Sik Kim) ; 김영균(Young Pyo Kim) ; 오규환(Kyu Hwan Oh) |
| Abstract |
Heat transfer, residual stresses and deformations during a multi-pass butt-welding of natural gas(NG) pipes have been analyzed using a 2-dimensional thermo-elastoplastic finite element method. A double ellipsoidal power density distribution model has been used to take into account the heat distribution by a moving arc, and an element birth technique has keen also used to model the multi-pass welding. The calculated sizes of FZ and HAZ are in good agreement with the experimentally measured one. The maximum residual effective stresses and effective plastic strain are found to be developed in the boundary between FZ and HAZ. The hoop residual stresses of inner surface of pipe are determined at the 1 and 2-pass of welding and those of outer surface are determined at the 3-pass of welding. |