U.S.-Federal Republic of Germany Cooperative Research on Phenomenological and Stochastic Viscoplasticity

该奖项支持伦斯勒理工学院的埃哈德克伦普尔博士 机械工程合作研究所。 技术大学力学研究所的Elmar Steck 位于德国联邦共和国布伦瑞克。 两个研究小组 研究机构正在研究粘塑性， 应力下材料非弹性行为的模型。 而 他们的理论有一些共同的特点， 完全不同的哲学或方法。 美国集团已 发展了一种现象学的，实验验证的粘塑性 理论的基础上过度应力;西德集团正在研究一个 随机的微观结构理论 他们的合作是 旨在给唯象粘塑性理论一个 微观结构的基础，并在扩展随机理论， 在一维和三维任意加载 公式化。 将使用RPI的优秀实验设施 来测试新出现的模型 现代材料和生产技术加上经济 要求导致重量减轻和日益严重的操作 各种机械设备的条件。 简单 预测材料应力性能的分析方法 已经不够用了 结构材料的最大极限状态 与非线性、非弹性行为有关; 行为只是在过去的十年左右才成为可能， 复杂的计算技术的可用性。 进一步 了解材料在应力作用下的行为， 材料模型可以预期从这种分析和综合， 可塑性研究的不同方法。

This award supports Dr. Erhard Krempl of Rensselaer Polytechnic Institute for collaborative research in mechanical engineering with Dr. Elmar Steck of the Institute of Mechanics at the Technical University of Braunschweig, Federal Republic of Germany. Research groups at both institutions are studying viscoplasticity by developing and testing models of the inelastic behavior of materials under stress. While their theories have some common characteristics, they are based on completely different philosophies or approaches. The U.S. group has developed a phenomenological, experimentally verified viscoplasticity theory based on overstress; the West German group is working on a stochastic, microstructurally based theory. Their collaboration is aimed at giving the phenomenological viscoplasticity theory a microstructural base and at extending the stochastic theory to arbitrary loading in one dimension and to a three-dimensional formulation. The excellent experimental facilities at RPI will be used to test the emerging models. Modern materials and production techniques together with economic demands have led to weight reduction and increasingly severe operating conditions for a great variety of mechanical equipment. Simple analytical methods for predicting performance of materials under stress are no longer adequate. Most limiting states of structural materials are associated with nonlinear, inelastic behavior; modeling such behavior has only become possible in the past decade or so with the availability of sophisticated computational techniques. Further understanding of material behavior under stress and improvement of material models can be expected from this analysis and synthesis of different approaches to the study of plasticity.