A Coupled Stress-Diffusion Model for Adhesively Bonded Single Lap Joint

This work presents the research conducted in order to complete the doctoral dissertation entitled "A Coupled Stress-Diffusion Model for Adhesively Bonded Single Lap Joints" It is submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Mechanical Engineering at Oakland University. The document is organized in the following manner:;Chapter One "Introduction and Literature Survey" gives the background about the stress distributions and mechanical behavior of adhesively bonded single lap joints. This chapter includes a brief description of the previous analytical, experimental and numerical works which is done in this field. At the end, it presents the motivation of this work.;Chapter Two "Coupled Shear Stress-Diffusion Model for Adhesively Bonded Single Lap Joints" presents an analytical model for the bond-line shear stress due to tensile--shear load considering the moisture diffusion effect subjected to shear tensile load. In the presented analytical model the effect of bending of single lap joint under a shear tensile load is neglected. For various moisture exposure time the shear stress distribution along the single lap joint bonding area is explored. Finally, the finite element simulation is compared with presented analytical model.;Chapter Three "Coupled Peel and Shear Stress-Diffusion Model for Adhesively Bonded Single Lap Joints" presents an analytical model for the bond-line peel and shear stresses due to tensile-shear load considering the moisture diffusion effect subjected to shear tensile load. In the presented analytical model the effect of bending of single lap joint under a shear tensile load is considered. It is, also, assumed that upper and lower adherends are similar in terms of material and geometry. For various moisture exposure time the peel and shear stresses distribution along the single lap joint bonding area is explored. Finally, the finite element simulation is compared with presented analytical model.;Chapter Four "Coupled Peel and Shear Stress-Diffusion Model for Dissimilar Material Adhesively Bonded Single Lap Joints" presents an analytical model for the bond-line peel and shear stresses due to tensile-shear load considering the moisture diffusion effect subjected to shear tensile load. In the presented analytical model the adherends dissimilarity along with effect of bending of single lap joint under a shear tensile load is considered. For various duration of moisture exposure time the peel and shear stresses distribution along the single lap joint bonding area is explored. At the end, the finite element simulation is compared with presented analytical model.;Chapter Five "Coupled Elasto-Plastic Diffusion Model for Predicting Cohesive Failure of Adhesively Bonded Single Lap Joints" present an analytical model to predict the failure load of the single lap joint considering moisture diffusion effect. In the presented analytical model the cohesive is assumed to be as the single lap joint is failure. The results explore the various moisture diffusion time on shear strength of adhesively bonded single lap joint.;Chapter Six "Cyclic Moisture Testing of Adhesively-Bonded Single Lap Joints" illustrate effect of cyclic salt fug spray on the mechanical performance composite-based lightweight material single lap joints using experimental and finite element methods. For various moisture exposure time, the maximum shear tensile strength (load transfer capacity) and corresponding failure mode investigated. Finite element simulation is used to illustrate the effect of salt fog diffusion on bond-line stress distribution of the single lap joint.;Chapter Seven "Conclusions and Future Work" summarizes the major findings of this dissertation research, and outline the potential for future work.