Seong-Woo 1, Michael Pecht 2, and Dennis L. O'Neal 3
1 Addis Ababa Science & Technology University, Faculty of Mech. Eng., Addis Ababa, Ethiopia
2 CALCE, Center for Advanced Life Cycle Engineering, Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20740, USA
3 Dean of Engineering and Computer Science, Baylor University, Waco, TX 76798-7356, USA
To improve the lifetime of mechanical system such as compressor, parametric accelerated life testing (ALT) as a reliability methodology is suggested. It consists of (1) a parametric ALT plan based on BX lifetime, (2) load analysis for accelerated lifetime test, (3) a tailored series of parametric ALTs with action plans, and (4) evaluation of the final compressor design to ensure the targeted BX lifetime is satisfied. As a test case, failed reciprocating compressors of French-door refrigerators returned from the field were studied. Disassembling the compressors revealed that the suction reed valve had fractured. In the first ALT, the failed samples from the field were reproduced. The root cause of the failures came from the sharp edges of the valve plate and an overlap between the suction reed valve and the valve plate. Corrective actions included modifying the valve plate in the compressor system to increase the trepan size and adding a ball peening process to eliminate sharp edges on the valve plate. There were no problems during the second ALT. After these parametric ALTs with corrective action plans were conducted, the modified compressor was expected to achieve lifetime of B1 life 10 years.