Friction, wear, and fatigue are examples of dissipative processes wherein the systemʼs free energy, responsible for doing useful work, decays with time. This decay in the free energy continues until the system attains a minimum at the equilibrium state in accordance with the principle of minimum free energy. Thus, the systemʼs path to the minimum free-energy is always accompanied by increasing entropy until it
reaches its peak value at the equilibrium state. The increase in entropy is a consequence of increasing disorder in the system with time. Therefore, notwithstanding the multiplicity of underlying dissipative processes, they share one unique feature: they all produce entropy. Therefore, thermodynamic entropy production is believed to be a propitious measure for a systematic study of friction, wear, and fatigue. In this lecture, I present the results of a series of experimental and analytical developments associated with surface degradation such as adhesive wear as well as fatigue fracture within this framework. This view offers a path forward for the development of the science of degradation applicable to a variety of applications.
Dr. Michael Khonsari
He earned his B.S., M.S., and Ph.D. in Mechanical Engineering from The University of Texas at Austin. He holds the Dow Chemical Endowed Chair and is a professor of Mechanical Engineering at Louisiana State University (LSU). His research is in the area of tribology and fatigue. He has published over 430 papers and 3 technical books. He is a Fellow of the National Academy of Inventors (NAI), American Association for Advancement of Science (AAAS), American Society of Mechanical Engineers (ASME), and Society of Tribologists and Lubrication Engineers (STLE).