Productization and instrumented testing of a corrosion fatigue test device

Abstract

Corrosion Fatigue has been identified as the limiting factor of submarine propulsion shaft operation intervals. Increasing the inspection interval from 6 to 12 years could save a significant amount of money on procurement and maintenance costs. Corrosion fatigue data is sparse and incomplete and an initial prototype of a fatigue testing device that more accurately reflects the operational loading of sub shafts was designed in a previous thesis. The U.S. Navy has identified the device as improvement on current testing methods. The primary purpose of the fatigue testing machine has been identified within a long-term testing plan for the Navy. In this work, the key aspects of the design have been updated. The manufacturing, setup, operation, and maintenance of the device have been provided. Instrumentation has been as part of an effort to monitor motor health and to explore the possibility of detecting crack initiation within the test shaft. The test device has been used to collect relevant data provide baseline data on artificially pitted samples and unpitted samples test shafts in seawater for the Navy. Artificial seawater was used for testing consistency. A continued testing regime is recommended and outlined. Last, further design updates and ideas are suggested.