Parametric Accelerated Life Testing (ALT) was used to improve the reliability of icemaker\nsystem with a fractured helix upper dispenser in field. By using bond graphs\nand state equations, a variety of mechanical loads in the assembly were analyzed. The\nacceleration factor was derived from a generalized life-stress failure model with a\nnew load concept. To reproduce the failure modes and mechanisms causing the\nfracture, new sample size equation was derived. The sample size equation with the\nacceleration factor also enabled the parametric accelerated life testing to quickly reproduce\nearly failure in field. Consequently, the failure modes and mechanisms\nfound were identical with those of the failed sample. The design of this testing should\nhelp an engineer uncover the design parameters affecting the reliability of fractured\nhelix upper dispenser in field. By eliminating the design flaws, gaps and weldline, the\nB1 life of the redesign of helix upper dispenser is now guaranteed to be over 10 years\nwith a yearly failure rate of 0.1% that is the reliability quantitative test specifications\n(RQ).
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