PSI - Issue 46

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2021) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 46 (2023) 169–174

© 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID 2021 Organizers Abstract This paper proposes using parametric accelerated life testing (ALT) as a systematic reliability approach to create a reliability quantitative (RQ) specification such as the mission cycle for pinpointing design faults in mechanical systems. It contains: (1) a system BX lifetime made on the parametric ALT scheme, (2) fatigue design, (3) adjusted ALTs with alternatives, and (4) an judgment of whether the system design(s) secures the objective BX lifetime. A life-stress model and a sample size formulation for parametric ALT are proposed. A cooling enclosure system in a refrigerator was utilized to demonstrate this system of methods. Evaporator tubes of a cooling enclosure were pitted from the marketplace. A failure analysis was carried out utilizing a scanning electron microscopy (SEM) with energy dispersive x-ray (EDX). The root cause of the involved evaporator tubes was recognized as the chlorine concentration in a cotton adhesive tape which was utilized to attach the evaporator tube to the inner case. The crevice (or pitting) corrosion mechanism happened on the evaporator tube outside. To reproduce it, a parametric ALT was implemented using a 3.69% saline solution on the evaporator tube. The consequences manifested that the evaporator tubes were pitted in a place where the cotton tape was fastened. The failure modes and mechanisms confirmed by parametric ALT were indistinguishable to those of the involved refrigerators in the field. To alter the design flaw with the refrigerator evaporator tube, the cotton tape was modified into a generic transparent tape. The lifetime of the cooling enclosure is now expected to have B1 life 10 years. © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID 2021 Organizers Keywords: Reliability Design; Evaporator Tube; Pitting Corrosion; Parametric Accelerated Life Testing; Design Flaw 5th International Conference on Structural Integrity and Durability Methodology to Improve the Reliability of the Cooling Enclosure System in a Refrigerator Seong-woo Woo a, *, Dennis L. O’Neal b , Yimer Mohammed Hassen a , Gezae Mebrahtu a a Mechanical Technology Faculty, Manufacturing Technology, Technical and Vocational Training Institute (TVTI), Addis Ababa PO box 190310, Ethiopia b Baylor University, Engineering and Computer Science, Department of Mechanical Engineering, Waco, TX 76798-7356, USA

* Corresponding author. Tel.: +251-90-047-6711;. E-mail address: twinwoo@yahoo.com

2452-3216 © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID 2021 Organizers

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ICSID 2021 Organizers 10.1016/j.prostr.2023.06.029