Seong-Woo Woo* Pages 279 - 286 ( 8 )
Background: A freezer drawer in a French door refrigerator subjected to repetitive food loading was found to have fractured in the field. Inspection of the field failures was carried out to determine the root causes in the design failures of the drawer. The primary failures came from a faulty design of the drawer that was not strong enough to withstand the loads caused by repetitive open and closing of the drawer.
Objective: Based on the analysis of field data and a tailored set of parametric Accelerated Life Tests (ALT), the freezer drawer system for food storage in the French refrigerator was redesigned to improve its reliability.
Methods: To carry out parametric Accelerated Life Tests (ALTs) using a force balance analysis, the simple mechanical loads of the drawer system were evaluated and an accelerated factor was found. Sample size equations with accelerated factors also were derived and used.
Results: For the first ALT, the handle of the freezer drawer was fractured. The failed shapes found in the tests were similar to those of the failed samples from the field. The drawer was redesigned by increasing the width of the reinforced handle. During the second ALT, the slide rails were fractured.
Conclusion: After the parameter ALTs, a corrective action plan was developed. The reliability of the newly designed freezer drawer system was assured to have a B1 life of 10 years with a failure rate of 0.1%/year. Recent patents on French refrigerators were also addressed.
Accelerated factor, freeze drawer system, missing design parameter, parametric accelerated life testing, reliability design, sample size equation.
Reliability Association of Korea, 146-102 Sunyoo-Ro, Yeongdeungpo-Gu, Seoul 150-103