%0 Journal Article
%T 毛刺形成中的韧性断裂条件及影响<br>Influences and Conditions of Ductile Fracture in Forming Process of Burr
%A 朱云明
%A 樊曙天
%A 王贵成
%A 陈云
%J 机械科学与技术
%D 2016
%X 在不同的切削条件下工件的棱边会形成毛刺与亏缺两种不同的形态。亏缺的形成同样影响着工件的精度与使用性能。基于Normalized Cockroft&Latham断裂准则建立了毛刺与亏缺形成的有限元热-力耦合模型,通过模拟结果分析,得出毛刺的形成主要由工件终端部材料的大塑性变形而产生,亏缺的形成主要由工件已加工面材料的大塑性变形造成的韧性断裂产生。并通过不同的切削条件模拟,得出了形成亏缺的界限条件。切削实验结果表明:模拟结果中的界限条件与实验结果接近。毛刺、亏缺形成有限元模型的建立为进一步深入研究其形成机理提供了一条有效的途径,其模拟结果为工件棱边质量的控制提供参考。<br>Two different typed shapes, including burr and fracture, can be formed in edges of workpiece under different cutting conditions. Also, fracture affects precision and performance of parts. A mechanical-heat coupling finite element model is established for simulating the forming process of burr and fracture based on the Normalized Cockroft & Latham ductile fracture criterion. According to the simulation results, it is found that the burrs forms due to the large plastic deformation of workpiece in the workpiece end surface, and the fracture forms due to the ductile fracture of workpiece in the machined surface. The critical parameters for fracture are obtained from the simulation results under different cutting conditions. It is found that the critical parameters obtained from the present model are close to the experimental results of cutting. The finite element model for burr and fracture provides an effective way for studying the forming mechanism of burr and fracture, and the simulation results provide the important reference for controlling the edge quality
%K 负毛刺
%K 韧性断裂
%K 有限元模型&lt
%K br&gt
%K ductile fracture
%K finite element model
%K negative burr
%U http://journals.nwpu.edu.cn/jxkxyjs/CN/abstract/abstract6415.shtml