Single-Lap Joints of Similar and Dissimilar Adherends Bonded with an Acrylic Adhesive

Abstract

In this study, the tensile strength of single-lap joints (SLJs) between similar and dissimilar adherends bonded with an acrylic adhesive was evaluated experimentally and numerically. The adherend materials included polyethylene (PE), polypropylene (PP), carbon-epoxy (CFRP), and glass-polyester (GFRP) composites. The following adherend combinations were tested: PE/PE, PE/PP, PE/CFRP, PE/GFRP, PP/PP, CFRP/CFRP, and GFRP/GFRP. One of the objectives of this work was to assess the influence of the adherends stiffness on the strength of the joints since it significantly affects the peel stresses magnitude in the adhesive layer. The experimental results were also used to validate a new mixed-mode cohesive damage model developed to simulate the adhesive layer. Thus, the experimental results were compared with numerical simulations performed in ABAQUS®, including a developed mixed-mode (I+II) cohesive damage model, based on the indirect use of fracture mechanics and implemented within interface finite elements. The cohesive laws present a trapezoidal shape with an increasing stress plateau, to reproduce the behaviour of the ductile adhesive used. A good agreement was found between the experimental and numerical results.

Keywords:

• Acrylic adhesive
• Cohesive damage model
• Finite Element Method
• Single-lap joints

ACKNOWLEDGEMENTS

The authors would like to thank Instituto de Engenharia Mecânica e Gestâo Industrial (INEGI) and Faculdade de Engenharia da Universidade do Porto (FEUP) for technical assistance. The first author wishes to thank Insitituto Politécnico do Porto/Instituto Superior de Engenharia do Porto (IPP/ISEP) for relief from teaching duties to complete the Ph.D. and Programa de Desenvolvimento Educativo para Portugal III (PRODEP III) for financial support.

Notes

(1-fibres direction, 2-transverse direction, 3-thickness direction).

Presented in part at the 2nd International Conference on Advanced Computational Engineering and Experimenting (ACE-X 2008), Barcelona, Spain, 14–15 July, 2008.