The Effect of Adherend Thickness and Width on Fracture Behavior in Adhesively bonded Double Cantilever Beam Joints

Abstract

In recent years, bonding joints are the most effective way to successfully and safely combine different materials in sectors such as automotive, aircraft and aerospace industries. In particular, the combination of composite materials, such as rivets, welds, non-conformity of traditional methods have been made use of bonding joints. The fracture behavior of the adhesive is important in adhesively bonded. In the present study, the fracture behavior of the adhesive was investigated experimentally under Mode-I loading of Double Cantilever Beam (DCB) joints obtained by using materials of different width and thickness. AA2024-T3 aluminum is used as the adherend and two component Araldite 2015 tough adhesive is used as adhesive. The fracture progression during the experiment was measured with a high-speed camera and the displacement was measured by a video extensometer. As a result; when the fracture energies of the experimentally obtained adhesive are examined, the fracture energy of the joint changes when the width and thickness of the adherend changes. In addition, the fracture energies of the joint obtained with the Corrected Beam Theory (CBT) and the Standard Test Method (SBT) are compared, and the fracture energy obtained with CBT is more accurate considering the elastic rotation in the adherend.

Keywords

• Adhesive joints,Fracture mechanics,Double cantilever beam test,Corrected beam theory,Standard test method

References

1. [1] Li, G., Pang, S.S., Woldesenbet, E., Stubblefield, M.A., Mensah, P.F. and Ibekwe, S.I. (2001). Investigation of prepreg bonded composite single lap joint. Composites Part B, 32:651-58, DOI: 10.1016/S1359-8368(01)00045-2.
2. [2] Liao, L., Huang, C. and Sawa, T. (2013). Effect of adhesive thickness, adhesive type and scarf angle on the mechanical properties of scarf adhesive joints. Int. J. Solids Struct., 50:4333-40, DOI: 10.1016/j.ijsolstr.2013.09.005.
3. [3] da Silva, L.F.M., Carbas, R.J.C., Critchlow, G.W., Figueiredo, M.A.V. and Brown, K. (2009). Effect of material, geometry, surface treatment and environment on the shear strength of single lap joints. Int J Adhes Adhes., 29:621-32, DOI: 10.1016/j.ijadhadh.2009.02.012.
4. [4] Gultekin, K., Akpinar, S. and Ozel A. (2014). The effect of the adherend width on the strength of adhesively bonded single-lap joint: Experimental and numerical analysis. Composites Part B, 60:736-45, DOI: 10.1016/j.compositesb.2014.01.022.
5. [5] Kanar, B. (2018). Investigation of Fracture Behavior of Nanostructure Added Under Ambient Temperature and Thermal Cycling, Erzurum Technical University, Master Thesis.
6. [6] ASTM 3433-99: (2012). Standard Test Method for Fracture Strength in Cleavage of Adhesives in Bonded Metal Joints. West Conshohocken, PA: ASTM International.
7. [7] Mohammadreza, K. and Farhad, A.M. (2012). Fracture analysis in adhesive composite material/aluminum joints under mode-I loading; experimental and numerical approaches. Int J Adhes. Adhes, 39: 8-14, DOI: 10.1016/j.ijadhadh.2012.06.005.
8. [8] Lopes, R.M., Campilho, R.D.S.G., da Silva, F.J.G. and Faneco, T.M.S. (2016). Comparative evaluation of the Double-Cantilever Beam and Tapered Double-Cantilever Beam tests for estimation of the tensile fracture toughness of adhesive joints. Int J Adhes. Adhes., 67: 103-111, DOI: 10.1016/j.ijadhadh.2015.12.032.

9. [9] Blackman, B.R.K., Kinloch, A.J., Rodriguez Sanchez, F.S., Teo, W.S. and Williams, J.G. (2009). The fracture behaviour of structural adhesives under high rates of testing. Eng Fract Mech., 76: 2868–2889, DOI: 10.1016/j.engfracmech.2009.07.013.
10. [10] BS 7991:2001 standard. Determination of the mode I adhesive fracture energy, GIC, of structural adhesives using the double cantilever beam (DCB) and the tapered double cantilever beam (TDCB) specimens.2001.
11. [11] Kanar, B., Akpinar, S., Akpinar, I. A., Akbulut, H. and Ozel, A. (2018). The fracture behaviour of nanostructure added adhesives under ambient temperature and thermal cyclic conditions. Theoretical and Applied Fracture Mechanics, 97: 120-130, DOI: 10.1016/j.tafmec.2018.08.006.