基于全量流动理论的管材弯曲过程失稳分析研究  

Analysis on Instability in Tube Bending Process Based on Total Theory of Plasticity

作　　者：车移 詹红 屈俊岑 林军[2] CHE Yi;ZHAN Hong;QU Jun-cen;LIN Jun(AVIC Chengdu Aircraft Industry(Group)Co.,Ltd.,Chengdu 610073,China;Southwest Technology and Engineering Research Institute,Chongqing 400039,China)

机构地区：[1]中航工业成都飞机工业(集团)有限责任公司,成都610073 [2]西南技术工程研究所,重庆400039

出　　处：《精密成形工程》2021年第3期112-117,共6页Journal of Netshape Forming Engineering

摘　　要：目的基于全量流动理论,研究管材弯曲成形过程中的外侧破裂和内侧起皱,分析其产生的原因及控制方法。方法采用理论解析方法,建立了管材弯曲变形应力、应变计算公式,推导管材外侧破裂和内侧起皱发生的判据,并试验验证了预测公式的可靠性。结果基于推导的应力、应变计算公式,依据临界许用变形程度,建立了管材外侧破裂判据;采用能量准则,提出了管材弯曲过程起皱发生公式,确定了起皱失稳计算公式的各个边界参数。结论试验与理论结果表明,构建的最小壁厚下许用R/r(弯曲半径与管材平均半径的比值)计算公式、基于起皱失稳计算的许用R/r(弯曲半径与管材平均半径的比值)计算公式均有较高精度,可用于指导弯管工艺参数设计与优化。Based on the total theory of plasticity,the purpose of this paper is to study the outer side cracking and inner side wrinkling in the tube bending process,and analyze the causes and control methods.In this paper,the theoretical analysis method is used to establish the calculation formula of stress and strain of tube bending deformation,deduce the criterion of tube outer cracking and inner wrinkling,and verify the reliability of the prediction formula by experiment.Finally,based on the derived stress and strain calculation formula,according to the critical allowable deformation degree,the cracking criterion of the outer side of tube is established;based on the energy criterion,the formula of wrinkling in tube bending process is proposed,and the boundary parameters of wrinkling(instability)formula are determined.The experimental and theoretical results show that the calculation formulas of allowable R/r(ratio of bending radius to average radius of tube)under minimum wall thickness and al-lowable R/r(ratio of bending radius to average radius of tube)based on wrinkling(instability)calculation have high accuracy,which can be used to guide the design and optimization of tube-bending process parameters.

关 键 词：管材弯曲 临界变形 能量法 破裂 起皱 

分 类 号：TG386[金属学及工艺—金属压力加工]