Modelling orthogonal machining of carbon steels. Part I: Strain hardening and yield delay effects
Modelling orthogonal machining of carbon steels. Part I: Strain hardening and yield delay effects
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碳钢正交加工建模。
DOI：
10.1016/j.ijmecsci.2009.03.007
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发表时间：
2009
影响因子：
7.3
通讯作者：
T. Childs
中科院分区：
文献类型：
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作者：
T. Childs
以前关于金属的流动应力行为如何影响加工中连续切屑形成的模型已经描述了流动应力纯粹依赖于应变的应变硬化指数。对于处于软化状态的铁金属，而非有色金属，在预测和实验过程力和切屑形式之间存在系统差异。本文在切屑形成的有限元分析中，对流动应力依赖于应变的描述中增加了屈服延迟，以及随之而来的上屈服点和屈服下降。结果表明，该方法减小了模拟结果与实验结果之间的差异。然而，达成完全协议所需的减产幅度可能比实际预期的要大。还需要做更多的工作来完全准确地对过程进行建模。这被认为是首次将屈服下降效应纳入加工过程的有限元分析中。此外，还报道了在有限元法中更新流动的径向回归法的发展。
Previous models of how a metal's flow stress behaviour influences continuous chip formation in machining have described flow stress dependence on strain purely in terms of a strain-hardening exponent. For ferrous metals in their softened state but not for non-ferrous metals there have been systematic differences between predicted and experimental process forces and chip forms. This paper adds yield delay, with its consequent upper yield point and yield drop, to the description of flow stress dependence on strain within a finite element analysis of chip formation. It shows that this reduces the differences between simulated and experimental observations in ferrous machining. However, the size of the yield drop required for complete agreement is perhaps larger than could realistically be expected to occur. More work is still required to model the process with complete accuracy. It is believed to be the first time that yield drop effects have been included in a finite element analysis of the machining process. Further, developments are reported in the radial return method of updating the flow within the finite element method.