Fatigue Behaviour of Multilayer Braided Fabric Reinforced Laminates

Abstract

In this paper, the fatigue behaviour of the laminated composites made from an epoxy matrix and four layers of flat regular braided carbon fiber fabrics of different braiding angles was investigated experimentally. Three laminate lay-ups were used. They are: [10⁰/10⁰/10⁰/10⁰], [28⁰/10⁰/10⁰/28⁰], and [28⁰/28⁰/28⁰/28⁰], where 10⁰ within the bracket indicates that the single layer braid lamina had a braiding angle of 10⁰ inclined with the longitudinal (loading) direction. The static tensile and tension-tension fatigue tests were conducted for those laminates, and detailed fatigue data are reported in the paper. Failure mechanisms of the tested laminates were also characterized. The stiffnesses and strengths (including static tensile and fatigue strengths) of the [10⁰/10⁰/10⁰/10⁰], [28⁰/10⁰/10⁰/28⁰], and [28⁰/28⁰/28⁰/28⁰] laminates were the highest, intermediate, and the lowest respectively. However, different failure mechanisms were recognized. It was found that under the uniaxial tensile or a high-level fatigue load, the [28⁰/28⁰/28⁰/28⁰] laminate failed catastrophically as a result of fiber breakage nearly across the cross section of the specimen. Delamination was seen only when a low-level fatigue load was applied to the laminate. In the case of the [10⁰/10⁰/10⁰/10⁰] laminate, a laminate longitudinal splitting was the main failure mode. No delamination accompanied the laminate failure. For the [28⁰/10⁰/10⁰/28⁰] laminate, significant delamination was found with any applied load (whether static or tensile fatigue of any load level). Splitting, both across the cross-sectional breakage and longitudinal, were involved in the failure of this combined laminate. These findings provide a useful insight into understanding the fatigue behaviour of braided fabric reinforced laminates.

References

Kostar

T. D.

, and Chou

T. W.

, Braided Structures, in 3-D Textile Reinforcements in Composite Materials, Miravete

ed., Woodhead Publishing Limited, Cambridge England (1999), pp. 217–238.

Hamada

, Effective braided preforms for crush elements in car, Proceedings of the International SAMPE Symposium and Exhibition, Volume 44 (II), 1999, pp. 2268–2276.

Thomson

, Braiding applications for civil infrastructure, SAMPE J., Vol. 35 (1999), pp. 38–41.

ICEX Socket System, http://www.ossur.com/products.icex.html.

Ramakrishna

, Ganesh

V. K.

, Teoh

S. H.

, Loh

P. L.

, and Chew

C. L.

, Fiber reinforced composite product with graded stiffness, Singapore Patent Application No. 9800874-1 (1998).

Fujihara

, Huang

Z. M.

, Ramakrishna

, Satkunanantham

, and Hamada

, Development of braided carbon/PEEK composite bone plates, Advanced Composite Letters, Vol. 10, No. 1 (2001), pp. 13–20.

Nakai

, Ohki

, Takeda

, and Hamada

, Mechanical properties and micro-fracture behaviours of flat braided composites with a circular hole, Composite Structures, Vol. 52, No. 3-4 (2001), pp. 315–322.

Harte

A. M.

, and Fleck

N. A.

, Deformation and failure mechanisms of braided composite tubes in compression and torsion, Acta Materialia, Vol. 48, No. 6 (2000), pp. 1259–1271.

Masters

J. E.

, Foye

R. L.

, Pastore

C. M.

, and Gowayed

Y. A.

, Mechanical Properties of Triaxially Braided Composites: Experimental and Analytical Results, J. of Comp. Tech. & Res., Vol. 15 (1993), pp. 112–122.

10.

Pluvinage

, ParviziMajidi

, and Chou

T. W.

, Damage characterization of two-dimensional woven and three-dimensional braided SiC-SiC composites, J. Mater. Sci., Vol. 31, No. 1 (1996), pp. 232–241.

11.

Chiu

C. H.

, and Cheng

C.C.

, Progressive crush behaviour in 3-D braided composite square tubes with various braiding parameters, Polymers & Polymer Composites, Vol. 8, No. 7 (2000), pp. 461–470.

12.

Harte

A. M.

, Fleck

N. A.

, and Ashby

M. F.

, Energy absorption of foam-filled circular tubes with braided composite walls, European J. of Mechanics A-Solids, Vol. 19, No. 1 (2000), pp. 31–50.

13.

Chiu

C. H.

, Tsai

K. H.

, and Huang

W. J.

, Effects of braiding parameters on energy absorption capability of triaxially braided composite tubes, J. Comp. Mater., Vol. 32, No. 21 (1998), pp. 1964–1983.

14.

Talreja

, Fatigue of composite materials, Lancaster, Technomic Pub. Co (1987).

15.

Hashin

, and Rotem

, A Fatigue Failure Criterion for Fiber Reinforced Materials, J. Comp. Mater., Vol. 7 (1973), pp. 448–464.

16.

Huang

Z. M.

, Micromechanical Life Prediction for Composite Laminates, Mechanics of Materials, Vol. 33, No. 4 (2001), pp. 185–199.