• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Optimal allocations of stress levels and test units in accelerated life tests.
【24h】

Optimal allocations of stress levels and test units in accelerated life tests.

机译：加速寿命测试中应力水平和测试单位的最佳分配。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Accelerated life testing (ALT) is a widely used approach for reliability demonstration and prediction of reliability of components or systems at normal operating conditions using data obtained at accelerated condition. The accuracy of reliability prediction depends on the stress types, stress levels and corresponding sample sizes. In this dissertation, we present efficient and practical approaches for determining the appropriate stress levels and number of test units at every stress level so as to obtain the most accurate reliability estimates at normal operating conditions.; Extensive research exists that deals with the accelerated failure time based (AFT-based) ALT plans. The proportional hazard (PH) is a much more realistic assumption in many cases in the reliability field; whereas PH-based test plans do not exist in the literature. In this research, we develop the first analytical ALT plans that utilize the PH model for reliability prediction. The plans determine the stress levels and the number of test units allocated to each level in an effort to minimize the variance of reliability estimate at normal operating conditions with constant stress application and Type-I censoring. Optimal test plans for simple step-stress and multiple-stress applications are also developed under the PH assumption.; The extended linear hazard regression (ELHR) model is a generalized model that encompasses the PH, the AFT and the extended hazard regression (EHR) models as special cases. In this research, we provide the first and most general study that applies the ELHR model in the ALT design. The test plans thus derived do not depend on the validity of the hazard rate proportionality assumption of the PH-based plans or the failure time proportionality assumption of the AFT-based plans. We establish the methodology for planning the optimal ALT plans under various stress applications, i.e. constant stress, step-stress and multiple-stress applications. Two types of baseline hazard functions are considered in the statistical model development—the quadratic baseline hazard and Hjorth's generalized baseline hazard.; We conduct an accelerated life test in the laboratory to investigate the time-dependent-dielectric-breakdown (TDDB) failure on n-type 4H-SiC MOS capacitors. The preliminary baseline experiment provides initial estimates of the ELHR parameters which are then used as input to the optimization problem of the test plans.
机译：加速寿命测试（ALT）是一种广泛使用的方法，用于使用在加速条件下获得的数据来演示和预测正常操作条件下组件或系统的可靠性。可靠性预测的准确性取决于应力类型，应力水平和相应的样本大小。本文提出了一种有效，实用的方法来确定合适的应力水平以及在每个应力水平下的测试单元数量，以便在正常工作条件下获得最准确的可靠性估计。现有大量研究涉及基于加速故障时间（基于AFT）的ALT计划。在可靠性领域中，在许多情况下，比例风险（PH）是一个更为现实的假设。而基于PH的测试计划在文献中不存在。在这项研究中，我们开发了第一个分析性ALT计划，该计划利用PH模型进行了可靠性预测。该计划确定压力等级和分配给每个等级的测试单元的数量，以在恒定的应力施加和I型检查的情况下，尽量减少在正常工作条件下的可靠性估计差异。还根据PH假设为简单的阶跃应力和多应力应用制定了最佳测试计划。扩展线性危害回归（ELHR）模型是一个通用模型，其中包含PH，AFT和扩展危害回归（EHR）模型作为特例。在这项研究中，我们提供了将ELHR模型应用于ALT设计的第一个也是最通用的研究。这样得出的测试计划并不取决于基于PH的计划的危险率比例假设的有效性或基于AFT的计划的故障时间比例假设的有效性。我们建立了在各种压力应用（即恒定压力，阶跃压力和多压力应用）下计划最佳ALT计划的方法。在统计模型开发中考虑了两种类型的基线危害函数：二次基线危害和Hjorth的广义基线危害。我们在实验室中进行了加速寿命测试，以研究n型4H-SiC MOS电容器随时间变化的介电击穿（TDDB）故障。初步的基线实验提供了ELHR参数的初始估计，然后将其用作测试计划优化问题的输入。

著录项

  • 作者

    Jiao, Lixia.;

  • 作者单位

    Rutgers The State University of New Jersey - New Brunswick.;

  • 授予单位 Rutgers The State University of New Jersey - New Brunswick.;
  • 学科 Engineering Industrial.
  • 学位 Ph.D.
  • 年度 2001
  • 页码 182 p.
  • 总页数 182
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 一般工业技术;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号