Evaluating Degradation Coefficients from Existing System Models

• Main Authors: Jude A. Osara, Michael D. Bryant
• Format: Article
• Language: English
• Published: MDPI AG 2021-03-01
• Series: Applied Mechanics
• Subjects: system analysis; degradation; thermodynamics; entropy generation; fatigue; lubricating grease
• Online Access: https://www.mdpi.com/2673-3161/2/1/10

A generalization of the Degradation-Entropy Generation (DEG) theorem to multi-disciplinary multi-physics system-process analysis via a combination with pre-existing system models is presented in this article. Existing models and the DEG methodology are reviewed, and a method for evaluating degradation coefficients <i>B_i</i> is proposed. These coefficients characterize the system’s transformation based on active dissipative mechanisms, including temperature effects. The consistency of entropy generation in characterizing degradation is then inherited by these often-empirical system models, thereby rendering them more robust and applicable to similar systems without the need for numerous tests and measurements for model corrections. The approach applies to all systems and can quickly analyze and predict a system’s performance and degradation, even in the absence of experimental data (using known properties and material constants). Demonstrated applications herein include mechanically loaded systems (frictional wear, grease shearing, fatigue loading), electrochemical energy systems, thermal processes, and others.