Delamination Buckling of Kevlar and Twaron Stitched Glass\Epoxy Composite Laminates by Experiments

Abstract:

In the present paper, effects of through-the-thickness stitching of delaminated glass/epoxy composite laminates with two different types of aramid threads, Kevlar® and Twaron® threads, on the buckling loads are studied. The buckling loads are predicted based on the Southwell, Vertical displacement and Membrane strain plot methods from the experimental data. Flexural modulus of the stitched and unstitched glass/epoxy composite laminates, knot tensile strength of Kevlar® and Twaron® stitching threads are obtained experimentally. From the Southwell, Vertical displacement and Membrane strain plot methods it is observed that stitching either by Kevlar® or Twaron® threads is effective in improving the buckling strength of glass/epoxy composite laminates when the delamination length is greater than 0.5L, L is the length of the laminate.

• Periodical: Solid State Phenomena (Volume 136)
• Pages: 109-114
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.136.109
• Online since: February 2008
• Authors: Madusudhanan R. Parlapalli, Kwok C. Soh, Dong Wei Shu
• Keywords: Buckling, Composite, Delamination, Experiment, Stitching

References

[1] H. Chai, C.D. Babcock, W.B. Knauss. One-dimensional modeling of failure in laminated plates by delamination buckling, Int J Solids and Structures; Vol. 17, (1981), pp.1069-1083.

DOI: 10.1016/0020-7683(81)90014-7

[2] L. Gui, Z. Li. Delamination buckling of stitched laminates, Composites Science and Technology, Vol. 61, No. 5, (2001), pp.629-636.

DOI: 10.1016/s0266-3538(00)00143-3

[3] M. Parlapalli, D. Shu. Effects of bridging on buckling analysis of tri-layer beams with separated delaminations, AIAA Journal, Vol. 44, No. 9, (2006), pp.2108-2117.

DOI: 10.2514/1.20248

[4] M. Parlapalli, D. Shu. Buckling analysis of two layer delaminated beams with bridging, European Journal of Mechanics-A/Solids, Vol. 25, No. 5, (2006), pp.834-853.

DOI: 10.1016/j.euromechsol.2005.10.004

[5] M. Parlapalli, K.C. Soh, D. Shu. Experimental Investigation of Delamination Buckling of Stitched Composite Laminates, Composites Part A: Applied Science and Manufacturing (Accepted, in Press).

DOI: 10.1016/j.compositesa.2007.05.001

[6] G.J. Simitses, S. Sallam, W.L. Yin. Effect of delamination of axially loaded homogeneous laminated plates, AIAA Journal, (1985), pp.1437-1444.

DOI: 10.2514/3.9104

[7] Y.B. Lim, I.D. Parsons. The linearized buckling analysis of a composite beam with multiple delaminations, Int J of Solids and Structures, Vol. 30, No. 22, (1992), pp.3085-3099.

DOI: 10.1016/0020-7683(93)90140-3

[8] D. Shu. Buckling of multiple delaminated beams, Int J Solids and Structures, Vol. 35, No. 13, (1998), pp.1451-1465.

DOI: 10.1016/s0020-7683(97)00124-8

[9] M.S.R. Parlapalli, D. Shu. Buckling of two-layer beams with an asymmetric delamination, Engineering Structures, Vol. 26, No 5, (2004), pp.651-658.

DOI: 10.1016/j.engstruct.2004.01.003

[10] P. MSRao, D. Sylvain, D. Shu. Buckling analysis of tri-layer beams with multiple separated delaminations, Composite Structures, Vol. 66, No 1, (2004), pp.53-60.

DOI: 10.1016/j.compstruct.2004.04.021

[11] P. MSRao, S. Hao, D. Shu. Buckling analysis of tri-layer beams with overlapped delaminations, Journal of Composite Materials, Vol. 39, No. 2, (2005), pp.109-125.

DOI: 10.1177/0021998305046435

[12] P. MSRao, T. Wenge, D. Shu. Buckling analysis of tri-layer beams with enveloped delaminations, Composites Part B: Engineering, Vol. 36, No. 1, (2005), pp.33-39.

DOI: 10.1016/j.compositesb.2004.04.014

[13] A.P. Mouritz, J. Gallagher, A.A. Goodwin. Flexural and interlaminar shear strengths of stitched GRP laminates following repeated impacts. Composite Sciences and Technology, Vol. 57, No. 5, (1997), pp.509-522.

DOI: 10.1016/s0266-3538(96)00164-9