基于M-C屈服准则的金属玻璃切削力学建模与实验研究

发布时间：2017-12-28 00:10

本文关键词：基于M-C屈服准则的金属玻璃切削力学建模与实验研究　出处：《燕山大学》2015年硕士论文　论文类型：学位论文

【摘要】：材料的微观结构决定其宏观性质。金属玻璃(非晶态合金)因具有短程有序、长程无序的原子组态而具有诸多优良的物理、力学特征,进而在航空航天,IT存储器等领域具有广泛的潜在应用前景。切削加工是材料零件成型加工的重要方法之一,而在切削机理的研究中切削力学特性是其重要组成部分。针对金属玻璃在材料力学试验中表现出的拉-压非对称性,并考虑该类材料的压力及温度敏感性,认为已有的适用于描述晶态材料屈服过程的Tresca、Mises等屈服准则不能很好地描述金属玻璃的切削形变屈服过程。本文尝试将M-C屈服准则引入金属玻璃切削力学特性的理论研究中来,同时考虑切削温度的影响建立其切削力解析模型,并进行实验验证,实验结果较好的证实了理论建模工作的有效性。具体研究内容如下:基于岩土结构与金属玻璃原子团簇结构的相似性,将适用于岩土力学领域的M-C屈服准则引入到金属玻璃切削加工的形变屈服中来。考虑金属玻璃剪切形变时对压力和温度的敏感特性,对M-C屈服准则加以改进后建立了适用于描述金属玻璃的正交切削力学解析模型。为了求解上述解析模型,在车削实验之后测量切屑厚度与宽度,利用最小做功原理得到了解析模型中的剪切角以及刀-屑摩擦角。采用热力学分析法将剪切面上的做功转化为切削温升后给出了切削模型中剪切面上的平均温度计算公式。利用切削力实测数据对上述模型进行了对比验证。实验结果表明,在同样的切削用量下,适用于传统晶态金属的切削力模型、未考虑切削温升的M-C准则切削力模型,以及考虑切削温升影响的M-C准则切削力模型三者当中,后者的计算精度最高。切削力模型的理论计算值与实测值之间的最大误差为14.8%,平均误差在8.9%。基于Tresca或Mises准则的传统解析模型与切削力实测结果的误差在59%以上,实验结果充分的证明了理论建模工作的有效性。
[Abstract]:The microstructure of a material determines its macroscopic properties. Metallic glass (amorphous alloy) has many excellent physical and mechanical characteristics due to its short range and long range disorder, and has potential applications in aerospace, IT memory and other fields. Cutting is one of the most important methods for the forming of material parts. In the study of the mechanism of cutting, the characteristics of cutting mechanics are the important part of the cutting mechanism. To show the metallic glass in material mechanics test of tension compression asymmetry, and considering the pressure and temperature sensitivity of the material, think of the existing crystalline material is applied to describe the process of Tresca and Mises yield criterion can well describe the cutting deformation of metallic glasses yield process. This paper attempts to introduce the M-C yield criterion into the theoretical research of metal glass cutting mechanical properties. At the same time, considering the influence of cutting temperature, the analytical model of cutting force is established, and the experimental verification is carried out. The experimental results confirm the validity of the theoretical modeling work. The specific research contents are as follows: Based on the similarity between geotechnical structure and metallic glass cluster structure, the M-C yield criterion applicable to geotechnical field is introduced into the deformation yield of metal glass cutting. Considering the sensitive characteristics of metal glass to pressure and temperature when shearing deformation is taken into account, an analytical model for orthogonal cutting mechanics of metallic glass is established after improving the yield criterion of M-C. In order to solve the above analytical model, the chip thickness and width were measured after turning experiment, and the shear angle and tool chip friction angle in the analytical model were obtained based on the least work principle. The calculation formula of the average temperature on the cutting surface in the cutting model is given by using the thermodynamic analysis method to convert the work on the shear surface into the cutting temperature rise. The model is compared and verified by the measured data of cutting force. The experimental results show that under the same cutting parameters, the cutting force model is suitable for traditional crystalline metals, the cutting force model without considering the M-C criterion of cutting temperature rise, and the M-C criterion of cutting force model considering the influence of cutting temperature rise, the latter has the highest accuracy of calculation. Three The maximum error between the theoretical and measured values of the cutting force model is 14.8%, and the average error is 8.9%. Based on Tresca or Mises criterion, the error between the traditional analytical model and the measured results of cutting force is over 59%. The experimental results fully demonstrate the validity of the theoretical modeling work.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG501

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