Investigation of Defect Effects on Adhesively Bonded Joint Strength Using Cohesive Zone Modeling

• Main Authors: Majid Jamal-Omidi, Mohammad Reza Mohammadi Suki
• Format: Article
• Language: English
• Published: Sciendo 2018-11-01
• Series: Journal of Mechanical Engineering
• Subjects: adhesively bonded joint; defect; cohesive zone modeling; strength prediction
• Online Access: https://doi.org/10.2478/scjme-2018-0023

In this paper, effects of the defect in an adhesively bonded joint have been investigated using cohesive zone modeling. Consequently, a 3D finite element model of a single lap-joint is constructed and validated with experiments. Strength prediction of current model is found desirable. Accordingly, different sizes of square shape defects are imported to model in the form of changing (raised or degraded) material properties (heterogeneity) and locally delaminated areas (as inclusion/void), respectively. Joint strength is investigated and a stress analysis is carried out for adhesive layer and adherends. Obtained Results show that, defect has significant impact on the results. It is found that at constant size of defect, local delamination has more impact on bonded joint strength than the heterogeneity. Furthermore, stress analyses demonstrate that the stress field does not change in adherends by taking defects into account. However, stress values decrease with degraded material properties and joint’s strength. Through evaluation of peel and transverse shear stresses in adhesive layer it is found that there is a change of stress distribution for both types of defects. Whereas, there is a considerable stress concentration in the delaminated adhesive layer.