基于起皱发生的铜钛双金属复合管小半径绕弯成形极限研究  

Research on the Forming Limit of Copper-Titanium Bimetallic Composite Tube with Small Radius of Rotary-Draw Bending Based on Wrinkling

作　　者：万苗苗 朱英霞[1] 陈蓉 涂文斌[1] WAN Miaomiao;ZHU Yingxia;CHEN Rong;TU Wenbin(School of Mechanical Engineering,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]江苏大学机械工程学院,江苏镇江212013

出　　处：《中国材料进展》2023年第3期266-271,共6页Materials China

基　　金：国家自然科学基金青年项目(51601070);国家自然科学基金面上项目(51875263)。

摘　　要：为了得到成形质量优良、小相对弯曲半径(R/D_(2)≤2,D_(2)是覆管外径)的铜钛双金属复合管,基于ABAQUS/Explicit有限元平台,建立了铜钛双金属复合管绕弯-回弹有限元模型,对铜钛双金属复合管小半径绕弯成形的起皱极限进行有限元模拟和分析。即在刚性芯模、不同芯头个数填充下,得到防止复合管起皱发生的最小相对弯曲半径(R/D_(2))_(min)。结果表明,基、覆管填充区的截面畸变率(φ)均明显小于非填充区,且填充区的φ随R/D_(2)减小略有增大,非填充区的φ随R/D_(2)减小而明显增大,这表明非填充区的截面起皱趋势明显高于填充区;R/D_(2)=1.76为起皱发生的分界线,当R/D_(2)=1.76时,1个芯头填充不满足复合管成形质量的要求;2个和3个芯头填充满足成形质量要求,且2个芯头填充效果较3个芯头好;当R/D_(2)=1.32时,3种填充条件都会出现起皱,不满足成形质量要求。为了确定最小相对弯曲半径,进一步分析了2个芯头填充、R/D_(2)=1.71和R/D_(2)=1.74时复合管的起皱情况,发现起皱个数N=1,φ_(max)均超过5%,不满足成形精度要求。综上,铜钛双金属复合管的成形极限为2个芯头填充、(R/D_(2))_(min)=1.76。In order to obtain the copper-titanium bimetallic composite tube with excellent forming quality and small relative bending radius(R/D_(2)≤2,D_(2) is the outer diameter of the covered tube),a finite element model for bending-springback process of copper-titanium bimetallic composite tube is established based on the ABAQUS/Explicit finite element platform in this paper,and the wrinkling limit of the copper-titanium bimetallic composite tube with small radius bending is simulated and analyzed by finite element method.That is,with a rigid mandrel and different numbers of mandrel cores filling,the minimum relative bending radius(R/D_(2))_(min) to prevent wrinkling is obtained.The results show that,the cross-section deformation ratesφin both the base tube and covered tube filling zones are significantly smaller than those in the non-filling zone.Theφin the filling zone slightly increased with the decrease of R/D_(2),while theφin the non-filling zone significantly increased with the decrease of R/D_(2).This indicates that the tendency for wrinkling in the cross-section of the non-filling zone is significantly higher than that in the filling zone.R/D_(2)=1.76 is the turning point for wrinkling occurrence.When R/D_(2)=1.76,one core filling does not meet the forming quality requirements.When two and three cores are filled,it meets the requirements of forming quality,and the filling with two cores is better than three cores.When R/D_(2)=1.32,wrinkles will appear under the three filling conditions,which does not meet the forming quality requirements.To determine the minimum relative bending radius,further analysis was carried out on the wrinkling of the composite pipe with two mandrel cores filling and R/D_(2)=1.71,R/D_(2)=1.74.It is found that number of wrinkles N=1 andφ_(max) exceeded 5%,which does not meet the forming quality requirement.Therefore,the forming limit of the copper-titanium bimetallic composite tube is two mandrel cores filled and(R/D_(2))_(min)=1.76.

关 键 词：双金属复合管 绕弯成形 起皱 成形极限 有限元分析 

分 类 号：TG306[金属学及工艺—金属压力加工]