N层过盈联接结合压力算法研究

过盈联接作为联接件间的传统配合方式,具有结构简单、承载能力高等优点,在机械工程领域有着广泛的应用,其研究大多数局限在单层或3层以内的联接.随着机械设备中多层过盈联接应用逐步增多,为进一步完善多层过盈联接设计理论,以厚壁圆筒理论为基础,通过分析过盈联接中各圆筒的几何关系,推导出过盈联接中过盈量与圆筒内、外表面径向位移的变化关系,得到了N层过盈联接结合压力与过盈量的矩阵表达式;用推导所得的解析法和Abaqus数值法,对比分析了过盈联接结合压力和过盈结合面两端存在的应力集中现象.结果表明:N层过盈联接中最内层过盈的结合压力随着过盈层数的增加而增加,结合压力由内到外依次减小;解析法和数值法的计算结果基本吻合,中点相对误差均在4%之内,说明该解析法可以为N层过盈联接设计提供可靠的理论指导.同时,数值法计算中显示在结合面两端存在应力集中,不同模型最内层过盈面的理论应力集中系数差别较小,且各模型中理论应力集中系数由内到外呈现依次增大的规律.提出的算法和所得规律对N层过盈联接的设计研究工作具有一定的指导和帮助.

Research on algorithm of coupling pressure of N-layer interference fit

As the traditional fit among interconnecting components,interference fit has such ad-vantages as high load-carrying capacity and simple structure,and it is widely used in mechanical engineering field.However,the majority of studies are limited within the interconnection of sin-gle layer or less than three layers.With the increasing of application of multi-layer interference fit in mechanical devices,in order to further improve design theory of multi-layer interference fit,on the basis of thick-walled cylinder theory,the relationship between the amount of interference and the displacement of inner and outer diameter was deduced through the analysis on the geometrical relationship among cylinders,and the equation of N-layer interference coupling which involved coupling pressure and amount of interference was derived.By means of the derived analytical method and Abaqus,the coupling pressure of interference fit and the stress concentration phe-nomenon on both ends of coupling surface were comparatively analyzed.The results showed that coupling pressure of inner layer increased with the increase of layer amount in N-layer interference fit,and the coupling pressure decreased from inner to outer layer,the results of ana-lytical method and numerical method were basically consistent,the relative error of medium point was less than 4%,which showed that such analytical method is reliable for N-layer interference fit design.Meanwhile,the numerical method showed that the stress concentration existed on both ends of the coupling surface,and the stress concentration factor was smaller in the inner lay-er of each model,while it increased from inner to outer layer.The proposed algorithms and rules can provide guidance and help for the design of N-layer interference fit.