EAGER: Constitutive Relations in Amorphous Metals

EAGER项目的研究目标是阐明非晶态金属的基本机制和本构关系。非晶或金属玻璃是一种结构无序的固体，没有长程平移有序。这种拓扑无序导致这类材料的一些最显着的机械性能。在过去的十年中，人们对材料的性能，特别是力学性能进行了广泛的研究和开发，并由此产生了几种本构关系。然而，这些关系遭受概念上的困难和缺乏关键的实验支持。特别是，两个本构模型将被测试：一个是基于Drucker-Prager准则和过渡态理论;第二，一个新的塑性理论，是自由能为基础的方法。FEM和原子建模都在计划中。本研究的最终目标是建立应力、应变、应变率、温度以及各种物理、结构性质和成分变化之间的非晶态固体本构关系，这是材料力学中迄今为止还没有工作本构模型的前沿领域之一。这项工作不仅有助于科学界更接近物理合理和工作的金属玻璃本构模型，而且还将使该领域朝着一般拓扑无序固体的变形公式化更进一步。因此，这一努力预计将有助于在固体力学领域的进步。相关的教育计划将与拟议的工作协同整合。

The research objective of this EArly-concept Grant for Exploratory Research (EAGER) project is to elucidate the fundamental mechanisms and constitutive relations in amorphous metals. Amorphous or metallic glass is a structurally disordered solid without the long-range translational order. This topological disorder leads to some of the most remarkable mechanical properties for this class of materials. In the past decade, extensive research and development have been done to harvest the properties, especially the mechanical properties, which led to several constitutive relations. However, these relations suffer from both conceptual difficulties and lack of critical experimental support. In particular, two constitutive models are going to be tested: one is based on Drucker-Prager criterion and transition state theory; and the second, a new theory for plasticity, is the free energy-based approach. Both FEM and atomistic modeling are planned. The ultimate goal of this research is to establish the constitutive relations among stress, strain, strain rate, temperature, and various physical, structural properties and compositional changes for amorphous solids, which is one of the remaining frontiers in mechanics of materials where no working constitutive model exists to date. This exercise will not only help the scientific community to get closer to more physically justified and working constitutive models for metallic glasses, but will also bring the field a step further toward formulation of deformation in topologically disordered solids in general. Thus this effort is expected to contribute to advancements in the area of mechanics of solids. Associated educational plans will be synergistically integrated with the proposed work.