Peng-Sheng Wei
National Sun Yat Sen University , Chinese Taipei
Physics Involved in Weld Bead Defects
Mechanisms of bead defects such as humping, gouging, rippling and other irregular surface patterns after solidification during melting, welding or drilling are systematically interpreted. Humping, gouging, and rippling usually accompanying porosity, undercut, segregation, stress concentration, etc. seriously reduce the properties and strength of the joint or melting. A systematical understanding of pattern formations from thermal physics is still limited. The effects of working parameters and properties on humping and rippling, however, can be systematically and parametrically interpreted from scale analysis presented in this work. The mechanistic findings for bead defects are useful for not only different welding processes but also other manufacturing and materials processing.
Dr. Peng-Sheng Wei received Ph.D. in Mechanical Engineering Department at University of California, Davis, in 1984. He has been a professor in the Department of Mechanical and Electro-Mechanical Engineering of National Sun Yat-Sen University, Kaohsiung, Taiwan, China, since 1989. Dr. Wei has contributed to advancing understanding of and to the applications of electron and laser beam, plasma, and resistance welding through theoretical analyses coupled with verification experiments. Investigations also include studies of their thermal and fluid flow processes, and formations of the defects such as humping, rippling, spiking and porosity. Dr. Wei has published more than 70 journal papers. He is a Fellow of AWS (2007), and a Fellow of ASME (2000). He also received the Outstanding Research Achievement Awards from both the National Science Council (2004), and NSYSU (1991, 2001, 2004), the Outstanding Scholar Research Project Winner Award from National Science Council (2008), the Adams Memorial Membership Award from AWS (2008), the Warren F. Savage Memorial Award from AWS (2012), and the William Irrgang Memorial Award from AWS (2014). He has been the Xi-Wan Chair Professor of NSYSU since 2009.