The Thermal Elastic-Plastic Finite Element Analysis Of Welding Residual Stress About Runner Of Large Hydraulic Turbine

Runner is a large structure, the connection between lamina and crown is welded, the connection between lamina and band is welded, the welding residual stress appeared in progress of welding is one of the important factors which affect the runner fatigue life. This paper calculate the welding residual stress of large runner by three-dimension thermal elastic plastic finite element, selecting the connection witch involve lamina and crown and band as the analysis model, so fully considering the influence between lamina and crown and band. In the progress of thermal analysis, use lumped mass element matrix to reduce the oscillation of thermal result;setup the appropriate load step to avoid the phenomena of temperature surge at originally load step;choose appropriate material parameter to ensure the convergence, with the order coupling thermal stress finite element, calculate the welding residual stress and residual deformation. Compared the welding residual stress with testing data, the both accord each other, and high temperature temper reduce the peak value of welding residual stress effectively. The calculating of welding residual stress establish the base of fatigue life analysis, offers the gist for considerig the affect of welding residual stress in the design of runner.