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

小行星9358123 本研究的目的是开发数值工具来分析制造中使用的常见成形过程，以便更好地预测这些操作期间和之后的材料行为。 感兴趣的具体工艺包括轧制、拉伸和挤出。 在这样的过程中，材料经历大的变形，材料的性质随着变形的进行而改变。 例如，多晶金属在变形时表现出应变硬化和诱导各向异性。 此外，在变形过程完成后，工件仍然保留残余应力。 金属的行为是由微观结构现象决定的，因此，以微观力学为基础可以得到一个更准确地表征材料行为的模型。 这将是有价值的，许多行业能够预测，通过廉价的数值模拟，材料性能和残余应力产生的一个给定的变形过程在给定的条件下，因为这些特性直接关系到产品的质量。 在过去，由于这些过程固有的复杂性，无法准确分析。 随着计算机功能的不断增强，对这些过程进行数值分析已成为现实。 这种能力将使制造商能够在实际实施改变之前以低成本调查其成形过程中的某些改变对其产品质量的影响。 此外，它还可以用作帮助设计新工艺的工具。

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.