Finite Element Analysis of Composite Wing T-Joints

Abstract

The present paper is concerned with numerical studies of composite T-joints which are made of carbon fibre composite (CFC) materials. CFC materials are used due to their high load carrying capacity and lightweight. The composite T-section is formed at the spar-lower skin joint section in aircraft wings. The behaviour of such joints is very complex. In this study, a brief account of the problem is first presented and areas of principal interest which most influence joint behaviour are identified. A thick composite shell finite element is specially developed and it is then used for a detailed finite element analysis of composite T-joints. Though several types of forces act on the spar, in the present case, a pull-out force is applied on the top of the web to determine strength and to study the behaviour of T-joints. Parametric variations account for two different stacking sequences and variations in filler area and radius of curvature at the web/skin interface. Accuracy of the present finite element analysis is established by comparing present results with the published ones. Numerical results obtained through parametric variations are presented and discussed to understand the joint behaviour.

Keywords

finite element composite joint composite shell element deflection stresses bending

Get full access to this article

View all access options for this article.

References

1. Gillesspie, J.W. Jr. and Pipes, R.B. (1978). Behavior of integral composite joints-finite element and experimental evaluation. Journal of Composite Materials, 12.

2. Cohen, D. and Hyer, M.W. (1991). Influence of geometric nonlinearities on skin-stiffener interface stresses. AIAA Journal, 3: 1055-1062.

3. Rispler, A.R. , Steven, G.P. and Tong, L. (1997). Failure analysis of composite T-joints including inserts. Journal of Reinforced Plastics and Composites, 16(18).

4. Thuis, H.G.S.J. and Wiggenraad, J.F.M. (1992). Investigation of the bond strength of a discrete skin-stiffener interface. NLR TP 92183 U.

5. Wiggenraad, J.F.M. and Bauld, N.R. Jr. (1991). Interlaminar stress analysis at the skin-stiffener interface of a grid stiffened composite panel. NLR TP 91011 U.

6. Rijn, J.C.F.N. van (1998). Failure criterion for the skin-stiffener interface in composite aircraft panels. NLR TP 98264.

7. Shenoi, R.A , Read, P.J.C.L. and Jackson, C.L. (1998). Influence of joint geometry and load regimes on sandwich T-joint behavior. Journal of Reinforced Plastics and Composites, 17.

8. Turaga, U.V.R.S. and Sun, C.T. (2000). Failure modes and load transfer in sandwich T-joints. Journal of Sandwich Structure and Materials, 2.

9. Bathe, K. (1997). Finite Element Procedures. New Delhi: Prentice Hall of India Private Limited.

10.

10. Cook, R.D. , Malkus, D.S. and Plesha, M.E. (1989). Concepts and Applications of Finite Element Analysis. New York: John Wiley & Sons.

11.

11. Jones, R.M. (1999). Mechanics of Composite Materials. Philadelphia: Taylor & Francis.