Numerical and Experimental Study of Tensile Strength of Single and Double-Strap Repairs

Abstract:

Article Preview

Adhesive bonding as a joining or repair method has a wide application in many industries. Repairs with bonded patches are often carried out to re-establish the stiffness at critical regions or spots of corrosion and/or fatigue cracks. Single and double-strap repairs (SS and DS, respectively) are a viable option for repairing. For the SS repairs, a patch is adhesively-bonded on one of the structure faces. SS repairs are easy to execute, but the load eccentricity leads to peel peak stresses at the overlap edges. DS repairs involve the use of two patches, one on each face of the structure. These are more efficient than SS repairs, due to the doubling of the bonding area and suppression of the transverse deflection of the adherends. Shear stresses also become more uniform as a result of smaller differential straining. The experimental and Finite Element (FE) study presented here for strength prediction and design optimization of bonded repairs includes SS and DS solutions with different values of overlap length (LO). The examined values of LO include 10, 20 and 30 mm. The failure strengths of the SS and DS repairs were compared with FE results by using the Abaqus® FE software. A Cohesive Zone Model (CZM) with a triangular shape in pure tensile and shear modes, including the mixed-mode possibility for crack growth, was used to simulate fracture of the adhesive layer. A good agreement was found between the experiments and the FE simulations on the failure modes, elastic stiffness and strength of the repairs, showing the effectiveness and applicability of the proposed FE technique in predicting strength of bonded repairs. Furthermore, some optimization principles were proposed to repair structures with adhesively-bonded patches that will allow repair designers to effectively design bonded repairs.

Info:

Periodical:

Materials Science Forum (Volumes 730-732)

Edited by:

Ana Maria Pires Pinto and António Sérgio Pouzada

Pages:

1018-1023

DOI:

10.4028/www.scientific.net/MSF.730-732.1018

Citation:

A. M.G. Pinto et al., "Numerical and Experimental Study of Tensile Strength of Single and Double-Strap Repairs", Materials Science Forum, Vols. 730-732, pp. 1018-1023, 2013

Online since:

November 2012

Export:

Price:

$38.00

[1] A. B. de Morais, A. B. Pereira, J. P. Teixeira, N. C. Cavaleiro, Strength of epoxy adhesive bonded stainless steel joints, Int. J. Adhes. Adhes. 27 (2007) 679-686.

DOI: 10.1016/j.ijadhadh.2007.02.002

[2] X. Liu, G. Wang, Progressive failure analysis of bonded composite repairs, Compos. Struct. 81 (2007) 331-340.

[3] R. D. S. G. Campilho, M. F. S. F de Moura, J. J. M. S. Domingues, Modelling Single and Double-Lap Repairs on Composite Materials, Compos. Sci. Technol. 65 (2005) 1948-(1958).

DOI: 10.1016/j.compscitech.2005.04.007

[4] C. Soutis, D. M. Duan, P. Goutas, Compressive behaviour of CFRP laminates repaired with adhesively bonded external repairs, Compos. Struct. 45 (1999) 289-301.

DOI: 10.1016/s0263-8223(99)00033-1

[5] E. A. S. Marques, L. F. M. da Silva, Joint strength optimization of adhesively bonded patches, J. Adhesion 84 (2008) 915-934.

DOI: 10.1080/00218460802505275

[6] F. Z. Hu, C. Soutis, Strength prediction of patch repaired CFRP laminates loaded in compression, Compos. Sci. Technol. 60 (2000) 1103-1114.

DOI: 10.1016/s0266-3538(00)00011-7

[7] L. F. M. da Silva, R. A. M. da Silva, J. A. G. Chousal, A. M. G. Pinto, Alternative Methods to Measure the Adhesive Shear Displacement in the Thick Adherend Shear Test, J. Adhes. Sci. Technol. 22 (2008) 15-29.

[8] Abaqus® HTML Documentation, Dassault Systemes, (2009).

[9] P. Reis, F. Antunes, J. A. M. Ferreira, Influence of superposition length on mechanical resistance of single-lap adhesive joints, Compos. Struct. 67 (2005) 125-133.

DOI: 10.1016/j.compstruct.2004.01.018

[10] L. F. M. da Silva, P. J. C. das Neves, R. D. Adams, J. K. Spelt, Analytical models of adhesively bonded joints-Part I: Literature survey, Int. J. Adhes. Adhes. 29 (2009) 319-330.

DOI: 10.1016/j.ijadhadh.2008.06.005

[11] L. F. M. da Silva, P. J. C. das Neves, R. D. Adams, A. Wang, J. K. Spelt, Analytical models of adhesively bonded joints-part II: comparative study, Int. J. Adhes. Adhes. 29 (2009) 331-341.

DOI: 10.1016/j.ijadhadh.2008.06.007

[12] R.D.S.G. Campilho, M.F.S.F. de Moura, D.A. Ramantani, J.J.L. Morais, J.J.M.S. Domingues, Tensile behaviour of three-dimensional carbon-epoxy adhesively-bonded single and double-strap repairs, Int. J. Adhes. Adhes. 29 (2009) 678-686.

DOI: 10.1016/j.ijadhadh.2009.02.004

In order to see related information, you need to Login.