Design of a Test Bench, Testing and problem solving of a mechanical device

The thesis consists in showing the thinking process associated with the development of a test bench, testing operations and consequent fast prototyping in the aerospace field. The project was made in a company (A.C.M.H. Ateliers de Construction Mécanique de Honfleur), during an internship, and was born after the unexpected failure of one of their products. The objective was to design a test bench able to recreate the utilization of the product, and then proceed with the cycling tests to determine the cause of the failure. But after analysis of the results, it evolved into the redesign of the product, so it can reliably last until a given target of utilization cycles. The test bench structure was designed in CAD, analysed with FEA softwares, and equipped with a pneumatic system to actuate the device. The pneumatic actuators were managed by a PLC, coded to handle the I/Os as well as the following of the testing procedure. It had to respect safety standards as well as be the most representative possible of the use of the device. The prototyping of a mechanical solution allowing the product to pass the cycling test required many iterations. It started from simple optimizations of the current setup but ended up in a drastic redesign of the product. Analysing and interpreting each time the results from the tests indicated the presence of different failure modes as well as multiple phenomenons contributing to the failures. Many solutions were considered, but due to the very harsh working conditions of the product (extreme temperatures, sand and dust atmosphere, salt spray corrosion resistance, ...) and the design constraints of the product itself, one solution emerged and, once tested, proved to exceed the targets of longevity required for the product. Once the last prototype successfully passed the cycling test on the bench, a derived version was made to be commercialized as a retrofit.