scholarly journals Effect of Sewing Threads on Interlaminar Shear Strength and Flexural Bending Strength of Stitched Non-Crimp Carbon Fabric Laminates

2006 ◽  
Vol 15 (6) ◽  
pp. 096369350601500
Author(s):  
Peter Mitschang ◽  
Amol Ogale
Keyword(s):  
Shear Strength ◽  
Carbon Fibre ◽  
Bending Strength ◽  
Positive Influence ◽  
Interlaminar Shear Strength ◽  
Cfrp Laminates ◽  
Short Beam ◽  
Carbon Fibre Reinforced Polymer ◽  
Interlaminar Shear ◽  
Sewing Threads

Interlaminar shear strength and flexural bending strength of stitched and non-stitched carbon fibre reinforced polymer (CFRP) laminates were studied with reference to three different sewing threads. The preforms were stitched through-the-thickness by two different hybrid carbon fibre threads and a Zylon (polyphenylen-2,6-benzobisoxazol, PBO) thread with 16 stitches/cm2 stitch density. The short beam interlaminar shear strength of the laminate increases where as flexural bending strength of the laminate shows mixed results depending on the stitching direction. Carbon fibre threads show relatively less positive influence on the laminate properties than the PBO thread. The results of this study differ partly from the literature studies.

Modified Short Beam Shear Test for Measuring Interlaminar Shear Strength of Composites

AIAA Journal ◽  
2002 ◽  
Vol 40 (11) ◽  
pp. 2368-2370
Author(s):  
Kunigal Shivakumar ◽  
Felix Abali ◽  
Adrian Pora
Keyword(s):  
Shear Strength ◽  
Shear Test ◽  
Interlaminar Shear Strength ◽  
Short Beam ◽  
Beam Shear ◽  
Interlaminar Shear

Microstructure optimizations for improving interlaminar shear strength and self-healing efficiency of spread carbon fiber/epoxy laminates containing microcapsules

2020 ◽  
Vol 55 (1) ◽  
pp. 27-38
Author(s):  
Yasuka Nassho ◽  
Kazuaki Sanada
Keyword(s):  
Shear Strength ◽  
Carbon Fiber ◽  
Optical Microscope ◽  
Interlaminar Shear Strength ◽  
Self Healing ◽  
Short Beam ◽  
Healing Efficiency ◽  
Beam Shear ◽  
Interlaminar Shear ◽  
Carbon Fiber Epoxy

The purpose of this study is to improve interlaminar shear strength and self-healing efficiency of spread carbon fiber (SCF)/epoxy (EP) laminates containing microcapsules. Microencapsulated healing agents were embedded within the laminates to impart a self-healing functionality. Self-healing was demonstrated on short beam shear specimens, and the healing efficiency was evaluated by strain energies of virgin and healed specimens. The effects of microcapsule concentration and diameter on apparent interlaminar shear strength and healing efficiency were discussed. Moreover, damaged areas after short beam shear tests were examined by an optical microscope to investigate the relation between the microstructure and the healing efficiency of the laminates. The results showed that the stiffness and the apparent interlaminar shear strength of the laminates increased as the microcapsule concentration and diameter decreased. However, the healing efficiency decreased with decreasing the microcapsule concentration and diameter.

Exploration relation between interlaminar shear properties of thin-ply laminates under short-beam bending and meso-structures

2017 ◽  
Vol 52 (17) ◽  
pp. 2375-2386 ◽  
Author(s):  
Chunfang Huang ◽  
Mingchang He ◽  
Yonglyu He ◽  
Jiayu Xiao ◽  
Jiangwei Zhang ◽  
...  
Keyword(s):  
Shear Strength ◽  
Carbon Fiber ◽  
Composite Laminates ◽  
Design Space ◽  
Interlaminar Shear Strength ◽  
Fiber Reinforced Polymer ◽  
Reinforced Polymer ◽  
Short Beam ◽  
Beam Bending ◽  
Interlaminar Shear

Carbon fiber reinforced polymer matrix composite laminates with standard thickness plies (0.125 mm) usually have weak interlaminar shear strength, meanwhile, for thin-thickness laminate structures such as aircraft wing skin, it is difficult to design a balanced laminate with the standard plies. It is a possible way to improve the interlaminar shear performance of carbon fiber reinforced polymer composite laminates and enlarge the design space of the thin-thickness structures by using thin-plies technology. In this paper, the interlaminar shear strength of carbon fiber/epoxy laminates with thin prepreg thickness subjected to short-beam bending is investigated. Unidirectional, cross-ply and quasi-isotropic laminate specimens were prepared by using prepregs with different ply thicknesses. Results show that, with decreasing of the ply thickness, higher interlaminar shear strength and smaller coefficient of variation of the data are obtained. Compared to laminates made by standard thickness prepreg, the laminates with thin-thickness prepreg exhibit more homogeneous microstructures and more regularly interlaminar shear stress distribution. This indicates that inherent anisotropy of the laminate composites is weakened in the thin-ply laminates and show pseudo-isotropic behavior. Especially in the case of ply thickness less than 0.020 mm, the interlaminar shear stress distributions of the cross-ply and quasi-isotropic laminate are almost the same with that of isotropic materials according to the classic laminate theory. On the other hand, as expected, the design space of the thin-thickness laminate structures will be increased since more ply number are allowed and superior interlaminar properties can be obtained due to the pseudo-isotropic behavior of the thin plies.

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