Sage Journals: Discover world-class research

Abstract

A cohesive layer model is employed for the prediction of initiation and tracking of interfacial crack growth in sandwich composite beams. A feature of the model is that it can be used for geometrically non-linear problems as it is formulated in terms of appropriate stresses and strains. Two types of sandwich specimens are selected for study: a sandwich beam specimen carrying a delamination at the top facing core interface with its bottom edge restrained, and a delaminated column specimen carrying axial compression. The beam was used to investigate the influence of the properties of cohesive layer material on its ability to predict the onset and progress of crack growth. It is found that the cohesive layer model is fairly robust and is not sensitive to change in parameters other than the critical strain energy release rate in the opening mode. Thus there is wide a latitude in the selection of parameters of the cohesive layer. The compression specimen exhibited a variety of phenomena, viz. delamination buckling, stable delamination growth, intervention of overall buckling, and finally unstable crack growth as the specimen sheds the load. The finite element analysis coupled with the cohesive layer model was able to follow all these stages of sandwich beam behavior. Good agreement between the model predictions and experimental results is found to exist in all the cases studied.

Keywords

sandwich beam delamination growth cohesive model energy release rate interfacial crack

Get full access to this article

View all access options for this article.

References

Avery, J. (1998). Compressive failure of delaminated sandwich composites. M.Sc. Thesis, University of Florida, Gainsville, Florida.

Avery, J. and Sankar, B.V. (1998). Compressive failure of debonded Sandwich Beams. In: Sankar B.V. (ed.), Recent Advances in Mechanics of Aerospace Structures and Materials. New York: ASME, Vol. 56, pp. 207-217.

Echtermeyer, A.T. and McGeorge, D. (June 9-11, 1998). Fracture Toughness of Core-face Sheet Interfaces of Sandwich Materials. Sandwich Construction Conference. The Royal Institute of Technology, Stockholm, Sweden.

Hibbitt, Karlsson and Sorensen, Inc. (1999). ABAQUS/Standard version 5.8.

Hwu, C. and Hu, J.S. (1992). Buckling and postbuckling of delaminated composite sandwich beams. AIAA J., 30(7): 1901-1909.

Li, X. (2000). Debonding fracture of foam core the tilted sandwich structure. Ph.D Thesis, Florida Atlantic University, Boca Raton, Florida.

Li, X. and Carlsson, L. (1999). The tilted sandwich debond (TSD) specimen for face/core interface fracture characterization. J. Sandwich Structures and Materials, 1: 60-75.

Mouritz, A.P. and Thomson, R.S , (1999). Compression, flexure and shear properties of a sandwich composite containing defects. Composite Structures, 44: 263-278.

Needleman, A. (1990). An analysis of tensile decohesion along an interface. J. Mech. Phys. Solids, 38(3): 289-324.

10.

Needleman, A. (1987). A continuum model for void nucleation by inclusion debonding. J. Appl. Mech., 54: 525-531.

11.

Sridharan, S. (2001). Displacement-based mode separation of strain energy release rates for interfacial cracks in bi-material media. International Journal of Solids and Structures, 38: 6787-6803.

12.

Whitcomb, J.D. (1981). Finite element analysis of instability related delamination growth. Journal of Composite Materials, 15: 403-425.

Performance of a Cohesive Layer Model in the Prediction of Interfacial Crack Growth in Sandwich Beams

Abstract

Keywords

Get full access to this article

References