This paper develops parametric accelerated life testing (ALT) as a systematic reliability method to produce the reliability quantitative (RQ) specifications—mission cycle—for recognizing missing design defects in mechanical products as applying the accelerated load, expressed as the inverse of stress ratio, R. Parametric ALT is a way to enhance the prediction of fatigue failure for mechanical systems subjected to repeated impact loading. It incorporates: (1) A parametric ALT plan formed on the system BX lifetime, (2) a fatigue failure and design, (3) customized ALTs with design alternatives, and (4) an assessment of whether the last design(s) of the system fulfills the objective BX lifetime. A BX life concept with a generalized life-stress model and a sample size equation are suggested. A domestic refrigerator hinge kit system (HKS), which was a newly designed mechanical product, was used to illustrate the methodology. The HKS was subjected to repeated impact loading resulting in failure of the HKS in the field. To conduct ALTs, a force and momentum balance was utilized on the HKS. A straightforward impact loading of the HKS in closing the refrigerator door was examined. At the first ALT, the housing of the HKS failed. As an action plan, the hinge kit housing was modified by attaching inside supporting ribs to the HKS to provide sufficient mechanical strength against its loading. At the second ALT, the torsional shaft in the HKS made with austenitic ductile iron (18 wt% Ni) failed. The cracked torsional shaft for the 2nd ALTs came from its insufficient rounding, which failed due to repeated stress. As an action plan, to have sufficient material strength for the repetitive impact loads, the torsional shaft was reshaped to give it more rounding from R0.5 mm to R2.0 mm. After these modifications, there were no problems at the third ALT. The lifetime of the HKS in the domestic refrigerator was assured to be B1 life 10 years.

中文翻译：

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改善承受反复冲击载荷的新型机械系统的疲劳

本文开发了参数化的加速寿命测试（ALT），作为一种系统的可靠性方法，以产生可靠性定量（RQ）规范（任务周期），以识别机械产品在施加加速载荷时缺失的设计缺陷，表示为应力比的倒数， R.参数ALT是一种增强对反复冲击载荷作用的机械系统疲劳失效的预测的方法。它包含：（1）在系统BX寿命上形成的参数化ALT计划，（2）疲劳失效和设计，（3）具有设计替代方案的定制ALT，以及（4）评估是否为该系统满足了目标BX寿命。建议使用具有广义寿命应力模型和样本大小方程的BX寿命概念。家用冰箱铰链套件系统（HKS），这是一种新设计的机械产品，用于说明该方法。HKS承受反复的冲击载荷，导致HKS在现场失效。为了进行ALT，在HKS上使用了力量和动量平衡。检查了HKS在关闭冰箱门时的直接冲击载荷。第一次ALT时，HKS的外壳出现故障。作为一项行动计划，对铰链套件外壳进行了修改，将内部支撑肋连接到HKS，以提供足够的机械强度来抵抗其载荷。在第二个ALT时，HKS中使用奥氏体球墨铸铁（Ni含量为18 wt％）制成的扭转轴失效。第二个ALT的扭转轴开裂是由于其舍入不充分而造成的，该舍入由于反复的应力而失败。作为行动计划，为了具有足够的材料强度来承受重复的冲击载荷，扭转轴经过了重新塑形，以使其从R0.5毫米到R2.0毫米更圆滑。经过这些修改后，第三个ALT没有问题。家用冰箱中HKS的寿命保证为B1寿命10年。