塑料容器与金属盖的过盈密封结构设计及有限元分析

Design and Finite Element Analysis of Interference Sealing Structure of Plastic Container and Metal Cover

目的 为研究包装容器的过盈密封性能,设计一种塑料容器与金属盖的过盈密封结构,研究其过盈量与材料属性(弹性模量、泊松比和摩擦因数)对容器密封性能的影响。方法 制定包装容器的结构设计方案,使用UG软件对塑料容器与金属密封盖的过盈联接结构进行三维建模。将接触部位过盈联接的力学模型模拟为圆筒的过盈配合模型问题,并进行理论计算,利用Ansys软件进行仿真验证。最后使用Ansys Workbench创建金属密封盖工作状态下的三维轴对称有限元分析模型,并对不同过盈量与材料属性下的接触应力进行比较。结果 金属密封盖与瓶口的接触应力随安装过盈量的增大而逐渐增大,且接触压力值与安装过盈量之间近似呈线性关系。弹性模量的改变对接触应力的影响较不明显,同时最大接触应力的变化趋势随弹性模量的变化而平稳增长。泊松比与摩擦因数对过盈联接的接触应力影响较小,接触应力数值随其参数的改变而发生波动。结论 在不超过材料屈服强度的条件下,应选用尽可能大的过盈量,同时可以适量增大弹性模量,以增强塑料容器与金属盖之间过盈联接的密封性能。

The work aims to design an interference sealing structure of plastic container and metal cover to study the sealing performance of packaging container and analyze the effects of interference amount and material properties(elastic modulus, Poisson’s ratio and friction coefficient) on the sealing performance of container. The structure design scheme of the packaging container was prepared and the interference connection between the plastic container and the metal sealing cover was modeled by UG software. The mechanical model of the interference connection of the contact part was simulated as a cylinder interference fit model and then theoretical analysis was carried out and Ansys was used to verify the simulation. Finally, Ansys Workbench was used to create a three-dimensional axisymmetric finite element analysis model under the working state of the metal sealing cover, and the contact stress under different interference and material properties was compared. The contact stress between the metal sealing cover and the bottle mouth increased with the increase of the mounting interference, and the relationship between the contact pressure and the mounting interference was approximately linear. The effect of elastic modulus on contact stress was not obvious, and the variation trend of maximum contact stress increased steadily with the change of elastic modulus. Poisson’s ratio and friction coefficient had little effect on the contact stress of interference connection. The value of contact stress fluctuated with the change of parameters. Therefore, under the condition of that the yield strength of the material is not beyond the specified value, the interference should be selected as large as possible, and the elastic modulus can be increased appropriately to enhance the sealing performance of the interference connection between the plastic container and the metal cover.