Axial and Torsional Dynamic Responses of Tubular Joints With an Annular Void

Abstract

Dynamic responses of adhesively bonded tubular joints subjected to a harmonic axial and torsional load are investigated. Adherents are assumed elastic and the adhesive is taken to be a linear viscoelastic material. The effects of adherents and adhesive properties on the joint response as well as on the shear stress amplitude distribution along the overlap are investigated for each case of harmonic loading. Furthermore, the effects of defects such as an annular void in the bond area on the axial and torsional dynamic responses and shear stress amplitude distributions in the bond area are studied. The results indicate that for tubular joint geometries and properties investigated the axial and torsional resonant frequencies of the joint are little affected with the adhesive loss factor. These resonant frequencies initially increase rapidly with increasing adhesive shear modulus. However, the resonant frequencies asymptotically approach a constant value with further increase in adhesive shear modulus. The results further show that the resonant frequencies of the joint may not get affected with the presence of a central void in the bond area. The distribution of shear stress amplitude in the joint area is obtained. The maximum shear stress is confined to the edge of the overlap for all applied loading frequencies. For the adhesive and adherents’ properties and geometries investigated, the maximum shear stress amplitude in the joint area is little affected by the presence of a central annular void covering up to 40% of the overlap length. However, a central void larger than 40% of the overlap length may be detrimental or beneficial to the joint strength. This depends on the applied loading frequency. A central void reduces the system axial and torsional resonant frequencies. This may depart the system further away from the applied loading frequency or may bring it closer. A system excited closer or further from to its resonant frequency will develop higher or lower shear stress amplitude in the bond area.