Stress Field Analysis in Orthogonal Cutting Process Using Digital Image Correlation Technique
Stress Field Analysis in Orthogonal Cutting Process Using Digital Image Correlation Technique
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DOI：
10.1115/1.4033928
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发表时间：
2017-03
影响因子：
4
通讯作者：
Dong Zhang;Xiaoming Zhang;Wen-Jie Xu;H. Ding
中科院分区：
文献类型：
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作者：
Dong Zhang;Xiaoming Zhang;Wen-Jie Xu;H. Ding
加工过程中的切削应力场对于理解切削力学以及预测表面完整性、刀具磨损和失效起着重要作用。非常需要在切屑形成区获得准确可靠的切削应力。本文提出了一种获取切削应力场的新方法。包含弹性和塑性部件的变形场可以通过数字图像相关（DIC）技术获得。以实验确定的变形场和材料本构模型作为输入，可以获得正交切削应力场。然而，挑战在于处理由于获得的图像不准确而导致的总变形中涉及的无穷小弹性变形的不准确。我们开发了一种基于机械平衡方程修正静水压力场的方法，以补偿弹性变形部分的误差。此外，采用基于最小二乘平面拟合位移数据子集的欧拉对数应变来降低图像噪声。可以提取并积分沿剪切面和刀具-切屑界面的应力分布，以计算切削力。通过将基于这种新方法预测的切削力与实验测量值进行比较来进行可行性研究。还对通过 DIC 技术获得的切削参数与有限元法 (FEM) 预测进行了比较。
Cutting stress field in machining process plays a significant role in the understanding of cutting mechanics and prediction of surface integrity, tool wear, and failure. It is in great need to get accurate and reliable cutting stresses in the chip formation zone. In this paper, a new methodology to obtain the cutting stress field is proposed. The deformation field containing elastic as well as plastic parts can be obtained via digital image correlation (DIC) technique. The orthogonal cutting stress field can be obtained with the experimental determined deformation field and material constitutive model as inputs. However, the challenge is to handle the inaccuracy of infinitesimal elastic deformation involved in the total deformation due to the inaccuracy of the obtained images. We develop a method to modify the hydrostatic pressure field based on mechanical equilibrium equations to compensate the inaccuracy of elastic deformation part. Besides, Eulerian logarithmic strain based on a least square plane fit on a subset of displacement data is adopted to reduce the image noise. The stress distribution along the shear plane and tool–chip interface can be extracted and integrated to calculate cutting forces. A feasibility study is performed by comparing the cutting forces predicted based on this new method against the experimental measurements. The comparison of cutting parameters obtained through DIC technique with finite element method (FEM) predictions is also made.