Chairman of Mechanical Engineering Department, Georgia Southern University, USA
Speech Title: Weibull-Johnson Probabilistic Techniques Applied to Engineering Fatigue Problems
Abstract: The probabilistic nature of fracture and fatigue life requires data scatter and the inherent risk associated with that scatter to be considered when establishing the acceptable life of a test population. The impact of the test population sample size upon the scatter associated with fatigue data sets must also be understood. The Weibull distribution pioneered in 1939 by Waloddi Weibull , and methods of simplified application developed by Leonard Johnson while at General Motors in the 1950's, have been used to predict the probabilistic fatigue failure of components and systems. The techniques have been used by the author and his colleagues to (1) determine the minimum number of fatigue tests necessary to determine the fatigue life of a population, (2) determine whether the fatigue life of one data set is significantly better than another (such as when comparing products from two vendors), and (3) to validate a Weibull-Johnson bin model of fatigue failure confidence. Several case studies the author has been involved with are presented.
Biography: Prof. Brian L. Vlcek is professor and department chair of Mechanical Engineering at Georgia Southern University. Most recently he chaired the committee that created the manufacturing engineering program, and was named interim-chair of manufacturing engineering upon the launch of the new department. Dr. Vlcek earned his B.S., M.S. and PhD in Mechanical Engineering from Rensselaer Polytechnic Institute in Troy, NY. His general areas of research interest for the last twenty years has been both Engineering Education & Assessment and Tribology, with a current emphasis on fatigue failure, rolling element bearing failure, probabilistic modeling of fatigue failure, Weibull Analysis of fatigue failure, and tribological properties of biolubricants and biofuel-contaminants. Dr. Vlcek was a research engineer with RPI's Institute for Wear Control and Tribology for 5-years, during which he demonstrated novel high temperature vapor lubrication techniques. He next served for five years, prior to coming to Georgia Southern, as a consulting research engineer and project manager at the Bureau of Engraving and Printing, where he solved failure problems related to currency printing manufacture. Dr. Vlcek has had researched associations with NASA spanning thirty-three years, and was a NASA summer faculty fellow or an invited summer academic visitor at NASA-Glenn Research Center from 2001-2013. Dr. Vlcek is the 2009-10 recipient of the Georgia Southern Medal for Excellence in Service. He is co-author of the 2012 paper awarded the Society of Tribologists and Lubrication Engineer's Wilbur Deutsch Memorial Award for outstanding applied paper. He is author or co-author of over 35 publications in his area of technical expertise and engineering education & assessment.