Coupling between inherent and machining-induced residual stresses in aluminum components
Coupling between inherent and machining-induced residual stresses in aluminum components
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DOI：
10.1016/j.ijmecsci.2021.106865
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发表时间：
2021-10
影响因子：
7.3
通讯作者：
Ritin Mathews;Sumair Sunny;Arif Malik;Jeremiah Halley
中科院分区：
文献类型：
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作者：
Ritin Mathews;Sumair Sunny;Arif Malik;Jeremiah Halley
研究了高速加工高深宽比铝合金构件时，固有残余应力（IRS）和加工诱导残余应力（MIRS）的耦合作用对最终残余应力（FRS）和变形的影响。这项工作的动机源于简化相关的数值研究，引起两个限制：第一，映射不兼容，不完整，和/或空间稀缺的IRS配置文件产生不切实际的扭曲和不正确的应力场在静态平衡。其次，通过元素删除，无效元素的方法，或布尔减法（去除）的材料的加工模拟要么忽略热和MIRS的影响，或实现它们的基础上简化的分析/经验模型。因此，这种做法妨碍了对IRS和MIRS如何耦合的透彻理解。因此，在这项工作中，两个锻铝7050块具有不同的IRS配置文件（基于应力释放）被认为是在这项工作中。迭代应力重建算法的实现，以数值模拟的空间完整的和完全兼容的IRS字段在每个铝块使用有限的数据从文献中记载的切口测量。二维正交切削模型被用来验证所采用的材料和损伤模型，以及阐明IRS和MIRS对FRS的影响。采用经过验证的材料和损伤定义的3D端铣模型，然后应用不同的刀具路径，以揭示IRS和MIRS的耦合效应的变形时，高速加工具有高深宽比壁的C形通道。结果表明，IRS和MIRS之间的相互作用是非线性的性质，从而对比的假设，允许他们的叠加，广泛报道，并在文献中采用。结果还表明，IRS和MIRS之间的非线性耦合根据加工零件内的应力分量和位置而变化。此外，研究结果表明，最终的部分变形显着影响的非线性耦合，以及具体的机床路径实施。
This work investigates the coupling of inherent residual stress (IRS) and machining-induced residual stress (MIRS) on the final-state of residual stress (FRS) and distortion when high-speed machining (HSM) high aspect-ratio aluminum components. Motivation for this work stems from the simplifications in related numerical investigations that give rise to two limitations: First, the mapping of incompatible, incomplete, and/or spatially scarce IRS profiles generates unrealistic distortions and incorrect stress fields during static equilibration. Second, the simulation of machining via element deletion, inactive elements approach, or Boolean subtraction (removal) of material either ignores thermal and MIRS effects, or implements them based on simplified analytical/empirical models. Such practices therefore prevent a thorough understanding of how IRS and MIRS are coupled. Accordingly, two wrought aluminum 7050 blocks having different IRS profiles (based on stress relief) are considered in this work. An iterative stress reconstruction algorithm is implemented to numerically model a spatially-complete and fully-compatible IRS field in each aluminum block using limited data from slitting measurements documented in the literature. A 2D orthogonal cutting model is used to validate the material and damage models employed, as well as to elucidate the influences of IRS and MIRS on FRS. A 3D end milling model, which adopts the validated material and damage definitions, is then applied with different tool paths to reveal the coupled effects of IRS and MIRS on the distortion when HSM a C-channel featuring high aspect-ratio walls. The results reveal that the interaction between IRS and MIRS is nonlinear in nature, thus contrasting assumptions allowing for their superposition, as are widely reported and adopted in the literature. The results also show that the nonlinear coupling between IRS and MIRS varies according to both the component and location of stress within the machined part. Moreover, the findings reveal that the final part distortion is significantly influenced by the nonlinear coupling, as well as the specific machine tool path implemented.