An analytical and experimental work was performed to study the mechanical properties of unidirectional preformed composites, which are made of fiber tows kmtted together with polyester thread in matrix. In addition, the effects of material parameters, such as knit space, tow size, fiber and matrix properties, and volume fractions of fiber and matrix, on the moduli and strengths of the preformed composites were also considered. During the period of investigation, an analytical model, based on micro-mechanics theories, was de veloped for predicting the moduli and strengths of the materials. In order to verify the analysis, experiments were also conducted during the investigation. All the tests were per formed according to the standard ASTM procedures. Overall, more than 200 specimens were tested in tension, shear, and compression. The test data were compared with the nu merical simulations calculated from the model. An excellent agreement was found be tween the data and the calculations.
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References
1.
Stanton, E.L. and T.E. Kipp. "A Model for Nonlinear 2D Carbon-Carbon Composite Structures and Materials," Proceedings of 25th Structures, Structural Dynamics and Materials Conference, Palm Springs, CA. pp 322-332 (1984)
2.
Herle, J.W.S. et al. Structural Mechanics of Fibers, Yarns, and Fabrics, Vol. 1 Wiley-Interscience, chapter 9 (1969)
3.
Chan, W.S. and Dan-Jumbo. " A Comparison of the Structural Behavior of Laminates Made of Kmtted Nonwoven Fabric and Laminates Made of Conventional Unidirectional Tapes," SAMPE Journal, 22(6):21-26 (Nov./Dec., 1986).
4.
Mignery, L.A. , T.M. Tan and C.T. Sun. "The Use of Stitching to Suppress Delamination in Laminated Composites," ASTM Symposium on Delamination and Debonding of Materials, Nov., 1983, Pittsburgh, PA (1983).
5.
Ishikawa, T., M. Matsushima and Y. Hayashi. "Effect of Local Coupling upon Linear and Nonlinear Behavior of Fabric Composites," Proceedings of Fifth International Conference on Composite Materials, ICCM-V, July 29-August 1, 1985, San Diego, CA pp 1267-1281 (1985).
6.
Ishikawa, T. and T.W. Chou. "One-Dimensional Micromechanical Analysis of Woven Fabric Composites," AIAA Journal, 21(12):1714-1721 (1982)
7.
Ishikawa, T. and T.W. Chou "Nonlinear Behavior of Woven Fabric Composites ," J. of Composite Materials, 17(5):399-413 (1983).
8.
Ishikawa, T. and T.W. Chou. "Stiffness and Strength Behavior of Woven Fabric Composites," J. of Material Science, 17:3211-3220 (1982).
9.
Ko, F., J. Bruner, A. Pastore and F. Scardino. "Development of Multi-Bar Weft-Insert Warp Knit Glass Fabrics for Industrial Applications," J. of Engineering for Industry , 102(4) 333-341 (Nov. , 1980).
10.
Ko., F., K. Krauland and F. Scardino. "Weft Insertion Warp Knit for Hybrid Composites," Proceedings of the Fourth International Conference on Composite Materials, ICCM-IV, Oct. 25-27, 1982, Tokyo, Japan. pp. 1169-1176 (1982).
11.
Cogswell, F.N. and U. Measuria "Aromatic Polymer Composites: Broadening the Range," SAMPE Journal, pp. 26-31 (Sep./Oct., 1985).
12.
Schwartz, P. , R.E. Fornes and M.H. Mohamed. "Tensile Properties of Triaxially Woven Fabrics under Biaxial Loading," J. of Engineering for Industry , 102:327-332 (Nov , 1980).
13.
Lord, R.P., J.R. Parson and J. Normandin "Twistless Yarns and Woven Fabrics Made Therefrom," Transactions of the ASME, 102:60-66 (Feb., 1980 ).
14.
Whitney, J.M. "Geometrical Effects of Filament Twist on the Modulus and Strength of Graphite Fiber-Reinforced Composites," Textile Research Journal, pp. 765-770 (Sept., 1966).
15.
Miyano, Y., M. Kanemitsu, T. Kumo and H. Kuhn. "A Study on Fracture Mechanisms of Umdirectional CFRP," SAMPE Journal, pp 33-40 (Sep./Oct., 1985)
16.
Chou, T.W. "The Effect of Transverse Shear on the Compressive Strength of Fiber Composites," Modern Developments in Composite Materials and Structures, the Proceedings of the Winter Annual Meeting of the American Society of Mechanical Engineers, Dec. 2-7, 1979, New York (1979).
17.
Sadowsky, M.A. , S.L. Pu and M.A. Hussain. "Buckling of Microfibers," J. of Applied Mechanics, pp. 1011-1016 (1967).
18.
Rosen, B.W. "Tensile Failure of Fibrous Composites," AIAA Journal , pp. 1985-1991 (Nov., 1964).
19.
Hashin, Z. and C. T. Herakovich (edited). Mechanics of Composite Materials, Proceedings of the IUTAM Symposium on Mechanics of Composite Materials, VPI, August 16-19 (1982).
20.
Tsai, S.W. "Structural Behavior of Composite Materials," NASA CR-71 ( 1964).
21.
Tsai, S.W. and Hahn, H.T.Introduction to Composite Materials. Lancaster, PA: Technomic Publishing Co., Inc. (1980).
22.
Noyes, J.V. and B.H. Jones.'Analytical Design Procedures for the Strength and Elastic Properties of Multilayer Fiber Composites," Proc. AIAA/ASME 9th Structures, Dynamics and Materials Conference, Paper 68-336 (1968).
23.
Tsai, S.W., D.F. Adams and D.R. Doner. "Effect of Constituent Material Properties on the Strength of Fiber-Reinforced Composite Materials," AFML-TR-66-190, Air Force Materials Laboratory (1966).
24.
Hashin, Z. "Theory of Fiber Reinforced Materials," NASA CR-1974 ( 1972).
25.
Wang, A.S.D. "A Non-Linear Microbuckling Model Predicting the Compressive Strength of Unidirectional Composites," ASME Paper No. 78-WA/Aero-1 ( 1978).
26.
Hahn, H.T. and J.G. Williams. "Compression Failure Mechanisms in Unidirectional Composites ," Composite Materials: Testing and Designing (Seventh Conference). ASTM STP 893, J. M. Whitney, ed. PA:American Society for Testing and Materials, pp 115-139 (1986).
27.
Schuerch, H. "Prediction of Compressive Strength in Uniaxial Boron Fiber-Metal Matrix Composite Materials," AIAA Journal , 4:102-105 (1966).
28.
Jones, R.M.Mechanics of Composite Materials. Scripta Book Company (1975).
29.
Chamis, C.C. and G.P. Sendeckyj. "Critique on Theories Predicting Thermoelastic Properties of Fibrous Composites," J. of Composite Materials , pp. 332-358 (July, 1968).
30.
Hyer, M.W. "Micromechanics of Compression in Unidirectional Composites," Techmcal Report 86-9 for Martin Marietta Aerospace (Aug., 1986 )
31.
ASTM D3039-76, "Standard Test Method for Tensile Properties of Fiber-Resin Composites."
