Mechanical characteristics of the interfaces and strength evaluation in adhesive bonded joints under impact loadings

本课题主要研究了粘接接头在冲击载荷作用下的应力分析，以及粘接接头在静载荷和重复载荷作用下的应力分析。1)采用弹塑性有限元法分析了冲击载荷作用下空心圆柱体的应力响应。演示了断裂过程。此外，还阐明了黏合剂与胶粘剂的杨氏模量比、黏合剂厚度和黏合剂尺寸对界面应力分布的影响。2)在杨氏模量较大的界面处发生断裂。实测结果与数值结果吻合较好。3)将轴对称弹性理论作为四体接触问题，分析了粘结收缩接头的应力分布。应力奇点发生在受载荷的端部界面处。强度是用得到的应力分布估计的。4)利用粘结收缩接头的应力分布估算粘结收缩接头的疲劳强度。对粘结收缩接头进行了疲劳试验。疲劳强度为静强度的五分之一。

This research project has dealt with the stress analysis of adhesive joints under impact loadings and bonded shrink fitted joints under static and repeated loadings.1) The stress response of hollow cylinders under impact loadings are analyzed by an elasto-plastic finite element. The process of rupture is demonstrated. In addition, effects of Young's modulus ration between the adherends and the adhesive, adhesive thickness and the sizes on the interface stress distributions were clarified.2) A rupture occurs from the interface with larger Young's modulus adherend. The measured results were in a fairly good agreement with the numerical results.3) The stress distributions in bonded shrink fitted joints are analyzed using axisymmetrical theory of elasticity as a four body contact problem. The stress singularity occurs at the interface of the end towhich the load isappl ied. The strength is estimated using the obtained stress distributions.4) The fatigue strength of bonded shrink fitted joints is estimated using the stress distribution in bonded shrink fitted joints. The fatigue tests for the bonded shrink fitted joints were carried out. The fatigue strength was found to be one-fifth of the static strength.