摘要
压合衬套冷挤压强化耳片孔挤压量与强化效果的对应关系难以获得,并且存在残余应力沿轴向分布不均及孔壁变形不均的问题,为此,对大孔径耳片孔压合衬套冷挤压强化工艺进行了研究,提出了一种带夹具的低成本工艺改进方法,并对改进后工艺的可行性进行了验证。首先,建立了压合衬套冷挤压强化耳片孔的有限元模型,开展了耳片孔冷挤压强化,探究了不同挤压量下耳片残余应力分布规律及孔壁变形规律;然后,采用有限元模型分析了耳片疲劳寿命与挤压量的映射关系;通过压合衬套冷挤压安装实验和X射线衍射仪应力检测实验,对压合衬套冷挤压强化耳片孔有限元模型的可靠性进行了验证;最后,提出了改进的压合衬套冷挤压强化工艺,并采用有限元方法对其有效性进行了验证。研究结果表明:冷挤压强化效果并非与挤压量呈正相关,而是在某一挤压量下取得峰值。采用改进后的压合衬套冷挤压强化工艺可改善耳片孔变形不均的问题,进一步延长耳片孔的疲劳寿命。
It is difficult to obtain the corresponding relationship between the extrusion amount and the strengthening effect of the press-fit bushing cold extrusion,and there are problems of uneven distribution of residual stress along the axial direction and uneven deformation of the hole wall.Therefore,the cold extrusion strengthening process of the press-fit bushing with large diameter lug hole was studied,a low-cost process improvement method with fixture was put forward,and the feasibility of the improved process was verified.Firstly,the finite element model of the cold extrusion reinforcement of the compression bushing was established,the cold extrusion strengthening of the ear hole was carried out,and the residual stress distribution law and the deformation law of the hole wall under different extrusion amounts were explored.Then,the finite element model was used to analyze the mapping relationship between the fatigue life of the ear piece and the extrusion amount.The reliability of the finite element model of the cold extrusion reinforced ear hole of the press-fit bushing was verified by the cold extrusion installation experiment of the compression bushing and the stress detection experiment of X-ray diffractometer.Finally,an improved cold extrusion strengthening process for press-fit bushings was proposed,and its effectiveness was verified by the finite element method.The research results show that the strengthening effect of cold extrusion is not positively correlated with the extrusion amount,but achieves a peak under a certain extrusion amount.The improved cold extrusion strengthening process of the press-fit bushing can improve the problem of uneven deformation of the ear hole and further improve the fatigue life of the ear hole.
作者
刘儒军
蔡晓
鲍益东
黄翔
LIU Rujun;CAI Xiao;BAO Yidong;HUANG Xiang(College of Mechanical&Electrical Engineering,Nanjing University of Aeronautics and Astronaut,Nanjing 210016,China;Wuhu Sate-owned Factory of Machining,Wuhu 241007,China)
出处
《机电工程》
CAS
北大核心
2024年第12期2204-2211,2251,共9页
Journal of Mechanical & Electrical Engineering
基金
国家自然科学基金资助项目(51975280)。
关键词
压合衬套
冷挤压强化有限元模型
残余应力
变形均匀性控制
疲劳寿命分析
冷挤压强化工艺
press-fit bushing
finite element model of cold extrusion strengthening
residual stress
deformation uniformity control
fatigue life analysis
cold extrusion strengthening process
