Stress Singularity Analysis of a Viscoelastic/Viscoelastic Bonded Joint

Measurement of bi-material interface bonding strengths has drawn considerable attentions because damages or failures are most likely to occur at the interfaces in many advanced materials and structures. However, the measurement of the interface bonding strength is hindered by the presence of the stress singularity at the interface corner. In order to determine the actual bonding strength of bi-material interface, the determination/elimination of the stress singularity is thus very crucial. This paper presents an analytical model for the determination of the stress singularity and its elimination for a viscoelastic/viscoelastic bonded joint. Two viscoelastic materials with different material properties are considered for this study. Each material is modelled as a standard linear solid and the properties of both materials are considered as time-dependent. The elastic-viscoelastic corresponding principle is used to find the analytical solution for the subjected viscoelastic/viscoelastic bonded joint from the available analytical solution for an elastic/elastic bonded joint. The developed solution is applied for a bonded joint between Polyvinyl-chloride (PVC) and Epoxy materials. It is found that the stress singularity at the interface corner may increase with time due to the viscoelasticity of the materials. Finite element analyses have also been carried out to verify the results obtained from the analytical solution and the two results are in good agreement.