US-Federal Republic of Germany Cooperative Research: Probabilistic Description of Creep Damage and Failure

该奖项支持利哈伊大学的特里·J·德尔菲教授， 对弗劳恩霍夫材料研究所进行长期研究访问 德国西部弗赖堡的机械师，他将主要在那里工作 Hermann Riedel博士，高温材料部门的负责人 部门 这项研究的目的是扩展一个确定性的 高温蠕变损伤与破坏模型 包括各种概率特征。 他们是 感兴趣的特点，如随机增长的蠕变损伤， 随机蠕变失效时间 主要途径 包括随机微分方程积分技术 给出了故障时间分布的一般表达式 由科尔曼开发。 随着对提高功率和效率的驱动， 能量转换装置的工作温度、结构 在较低温度下被抑制或不明显的失效模式 温度变得更加重要。 一个最重要的 能量转换装置的高温失效模式是蠕变 破裂 拟议的研究将提供一个描述 蠕变损伤过程是一个物理上和概率上 也就是说，它将能够预测 在给定的时间t内失效。“这将产生更有用的 结构可靠性的估计比目前确定的 模型

This award supports Professor Terry J. Delph of Lehigh University for a long term research visit to the Fraunhofer Institute for Material Mechanics in Freiburg, West Germany, where he will work primarily with Dr. Hermann Riedel, head of the High Temperature Materials Department. The goal of this research is to extend a deterministic model for high-temperature creep damage and failure recently developed by Dr. Riedel to include various probabilistic features. They are interested in features such as random growth of creep damage and random creep failure times. The principal avenues of approach include integration techniques for stochastic differential equations and a general expression for the distribution of failure times developed by Coleman. As the drive for increased power and efficiency leads to higher operating temperatures for energy conversion devices, structure failure modes which were either suppressed or not apparant at lower temperatures become of greater importance. One of the most significant high-temperature failure modes in energy conversion devices is creep rupture. The proposed research will provide a description of the creep damage process that is both physically and probabilistically based; that is, it will be capable of predicting the probability of failure by a given time "t." This will produce much more useful estimations of structural reliability than current deterministic models.