塑性材料超声振动切削变形区分析

Analysis of Deformation Zone during Ultrasonic Vibration Cutting Process of Plastic Material

基于商用有限元软件ABAQUS,以切削高温合金为例,采用新的弹塑性材料本构关系,建立振动切削下刀具与工件接触二维正交模型,分析材料去除机理,研究切削力、变形区的应力分布变化规律等,并进行动态冲击切削试验加以验证.研究发现:相比普通切削,振动切削时第一变形区离刀具较近处在刀具一次振动冲击时即达到材料强度极限,自身内部发生损伤破坏,只需刀具以很小的力推进即可切除,符合振动切削超前损伤机理;此外,第三变形区处振动切削应力最大值小于普通切削的,故摩擦挤压程度较小,与振动切削塑性材料加工表面质量较高的事实一致.

Based on commercial finite element software ABAQUS,this paper takes cutting high temperature alloy as an example. Using the constitutive relation of elastic-plastic materials, the two dimensional orthogonal model of cutting tool and workpiece in vibration cutting is established. The material removal mechanism was analyzed, and the change law of the stress distribution in the cutting force and the deformation zone was stud-ied. The dynamic impact cutting test is carried out to verify the conclusion. Compared with the ordinary cut-ting ,ultimate strength is reached at the first deformation zone near the tool due to a vibration shock during vi-bration cutting and damage internally generated in the material which can be removed with a very small propul- sion force of tool. This fits the explanation of early damage mechanism during vibration cutting. In addition, the maximum stress at the third deformation zone during vibration cutting is smaller than that of ordinary cut-ting ,so the friction and extrusion degree is smaller, which is consistent with the fact that the surface quality of the plastic material during vibration cutting is better than that during ordinary cutting.