RUI: Plastic Instability and Models of Failure in the Uniaxial Compression of Porous Cylinders

本建议是关于镦锻的理论研究 用于确定材料的可成形性。 后者通常基于应变准则， 关联所有观察到的失效模式。李医生会用更多的 现实的多孔塑性，这是基于空隙成核， 生长和合并，在有限元模型中模拟镦粗 锻造 应力和应变分布的详细历史， 以及空隙增长的演变将被用来预测 失效模式 理论结果将根据 现有的数值和实验结果。的重要物质 然后将使用由此识别的处理变量来预测 其它金属成形工艺，例如锻造， 挤压和轧制。虽然年轻，李博士最有可能 成功地实现了他的研究目标， 本科院校。

This proposal is concerned with a theoretical study on upset forging of cylinders which is used to determine the material formability. The latter is normally based on a strain criterion which cannot correlate all observed failure modes. Dr. Lee will use the more realistic porous plasticity, which is based on void nucleation, growth and coalescence, in a finite element model to simulate upset forging. Detailed histories of stress and strain distributions as well as the evolution of void growth will be used to predict the failure modes. The theoretical results will be evaluated against existing numerical and experimental results. The important material and processing variables thus identified will then be used to predict the failures of other metal-forming processes, such as forging, extrusion and rolling. Although young, Dr. Lee is most likely to succeed in meeting his research objectives at this Predominantly Undergraduate Institution.