2023 ASEE Annual Conference & Exposition

An improvement in capability to better manage and reduce degradation of materials in U.S. Navy’s assets requires a workforce educated and trained in the application of the tools, principles, and practices of fatigue and fracture mechanics. However, the current level of effectiveness of failure engineering curricula in universities is not sufficient to address the Navy’s need to improve safety and reliability and reduce costs due to premature fatigue and fracture failure. Many of the Navy assets are experiencing cyclic mechanical loads during their lifetimes which result in fatigue crack initiation and growth and eventually premature failure. The understanding of fatigue crack initiation and growth mechanisms at microscales, where materials microstructure plays a significant role in fatigue mechanism, is of paramount importance. The senior design (capstone) program in the mechanical engineering (ME) program at our university with the support of the Department of Navy has implemented the fatigue test design challenges into the senior design course. In this paper, we present the design and development of micro-fatigue testing device for conducting in-situ fatigue testing in a Scanning Electron Microscope (SEM). The device is capable of conducting user defined fatigue loading scenarios in and ex-situ of an SEM. The device was prototyped by a senior design team of four ME students and is relatively small, lightweight, and fully programmable. It provides capabilities to observe the deformation and crack growth in real-time under SEM.