The School of Mechanical and Materials Engineering Seminar Series, “Creep-fatigue crack growth modeling using a strip-yield technique” Presented by Dr. Gabriel Potirniche
About the event
Creep-fatigue crack growth modeling using a strip-yield technique
Presented by Dr. Gabriel Potirniche, Associate Dean and Professor of Mechanical Engineering, College of Engineering, University of Idaho
Abstract
Creep-fatigue crack growth is a common failure mode in structures and components subjected to elevated temperatures and fluctuating mechanical loads. A few examples include components used in power plant applications or jet engines for the aerospace industry.
In this presentation, a computational Strip-Yield Model for Creep-Fatigue Crack Growth (SYM-CFCG) is introduced to demonstrate how to simulate creep-fatigue failure lives. The SYM-CFCG predictive scheme relies on computing plasticity-induced crack closure (PICC) near the tip of a growing crack. In this method, an effective stress intensity factor range is computed to account for the driving force at the crack tip. The crack plane is meshed with several one-dimensional elements placed throughout the cracked ligament and in the plastic zone ahead of the crack tip. SYM-CFCG software calculates crack opening and closing, residual stresses at minimum load, and crack growth rates per cycle.
SYM-CFCG simulation results of crack growth in common fracture mechanics specimens are compared with experimental measurements and predictions from the finite element method using ABAQUS. These comparisons are performed for several types of alloys, such as steels, aluminum alloys and nickel-base alloys. A good agreement is obtained using the two computational methods and experimental measurements. The SYM-CFCG approach highlights how the synergistic contributions of fatigue and creep loads during complex operating conditions can be accounted for in order to compute service lives in structural components.
Biography
Dr. Gabriel Potirniche is a professor of Mechanical Engineering and the Associate Dean of the College of Engineering at the University of Idaho. Dr. Potirniche received his doctorate from Mississippi State University in 2003 and joined the University of Idaho in 2007 as an assistant professor. Between 2020 and 2023 he was the Chair of the Mechanical Engineering Department. Dr. Potirniche teaches engineering mechanics courses on several topics at both the undergraduate and graduate levels. His research expertise is developing mathematical and computational models of material behaviors, such as elasticity, plasticity, creep, damage, fatigue, and fracture. He also developed models for other physical phenomena such as high-rate mechanical impacts and thermoelectricity. Dr. Potirniche is a licensed professional engineer in Idaho and a member of the American Society of Mechanical Engineers and the America Society of Engineering Education. He has published over 70 book chapters and technical papers in journals and conference proceedings. His interdisciplinary research has been funded by the Department of Energy, Department of Defense, National Science Foundation, Micron Technology, Murdock Charitable Trust, Alcoa Technical Center, and II-VI Foundation.