NSF Young Investigator: Numerical Analysis of Metal Forming Processes Based on Micromechanics

9358123工艺本研究的目的是开发数值工具来分析制造中常用的成形工艺，以便更好地预测在这些操作过程中和之后的材料行为。感兴趣的特定工艺包括轧制、拉拔和挤压。在这样的过程中，材料经历了大变形，材料的性质随着变形的进行而改变。例如，多晶金属在变形时既表现出应变硬化，又表现出诱发的各向异性。此外，在变形过程完成后，工件仍保留残余应力。金属的行为是由微观结构现象决定的，因此，以细观力学为基础可以得到一个更准确地描述材料行为的模型。对于许多行业来说，能够通过廉价的数值模拟来预测在给定条件下由给定变形过程产生的材料特性和残余应力将是有价值的，因为这些特性直接关系到产品的质量。在过去，由于固有的复杂性，这些过程无法被准确地分析。现在，随着计算机的功能和能力的不断增强，对这些过程的数值分析正在成为现实。这种能力将使制造商能够在实际实施这些变化之前，以低成本调查其成形过程中的某些变化对其产品质量的影响。此外，它还可用作辅助设计新流程的工具。

9358123 Maniatty The purpose of this research is to develop numerical tools to analyze common forming process used in manufacturing in order to better predict material behavior during and subsequent to these operations. Specific processes of interest include rolling, drawing, and extrusion. In such processes, where the material undergoes large deformations, the properties of the material change as the deformation proceeds. For example, polycrystalline metals exhibit both strain hardening and induced anisotropy as they are deformed. In addition, after the deformation process is complete, the workpiece still retains residual stresses. The behavior of metals is determined by microstructural phenomena, therefore, using micromechanics as a basis can lead to a model which more accurately characterizes the material behavior. It would be of value to many industries to be able to predict, via inexpensive numerical simulations, both the material properties and the residual stresses resulting from a given deformation process under given conditions, as these characteristics are directly related to the quality of the product. In the past, these processes could not be accurately analyzed due to the inherent complexity. Now with the increasing power and capabilities of computers, numerical analysis of these process is becoming a reality. Such capabilities would enable a manufacturer to investigate, at low cost, the effect on the quality of their product of certain changes in their forming process before actually implementing the changes. In addition, it could also be used as a tool to aid in the design of new processes.