TY - JOUR
T1 - Mechanical behaviors of Kevlar 49 fabric subjected to uniaxial, biaxial tension and in-plane large shear deformation
AU - Zhu, Deju
AU - Mobasher, Barzin
AU - Vaidya, Aditya
AU - Rajan, Subramaniam
PY - 2013/1/24
Y1 - 2013/1/24
N2 - Woven fabrics are used in many applications, including ballistic armors, propulsion engine containment systems and fabric reinforced composites. In order to facilitate the design and improvement of such applications, this paper investigates the stress-strain response in warp and fill directions, the apparent Poisson's ratio, and the in-plane shear response of Kevlar 49 fabric including the possible effects of specimen size and pre-loading on the mechanical responses of the fabric. Full-field image analysis of the fabric under shear deformation is used to better understand the mechanisms related to in-plane shear. The experimental results show that the fabric exhibits non-linear and orthogonal behavior in tension, and can deform up to 20% before complete failure. It has identical Young's modulus (pre-peak elastic stiffness) in warp and fill directions, but has different crimp strain, tensile strength and ultimate strain. The apparent Poisson's ratio is a nonlinear function of strain and dependent upon the levels of pre-loading. It increases with strain quickly at the beginning and decreases gradually until the fabric fails. The shear response is highly nonlinear and has four distinct regions: linear elastic rotation region, dissipative rotation region, yarn compression region and shear locking region, and it is not dependent upon specimen size after normalization.
AB - Woven fabrics are used in many applications, including ballistic armors, propulsion engine containment systems and fabric reinforced composites. In order to facilitate the design and improvement of such applications, this paper investigates the stress-strain response in warp and fill directions, the apparent Poisson's ratio, and the in-plane shear response of Kevlar 49 fabric including the possible effects of specimen size and pre-loading on the mechanical responses of the fabric. Full-field image analysis of the fabric under shear deformation is used to better understand the mechanisms related to in-plane shear. The experimental results show that the fabric exhibits non-linear and orthogonal behavior in tension, and can deform up to 20% before complete failure. It has identical Young's modulus (pre-peak elastic stiffness) in warp and fill directions, but has different crimp strain, tensile strength and ultimate strain. The apparent Poisson's ratio is a nonlinear function of strain and dependent upon the levels of pre-loading. It increases with strain quickly at the beginning and decreases gradually until the fabric fails. The shear response is highly nonlinear and has four distinct regions: linear elastic rotation region, dissipative rotation region, yarn compression region and shear locking region, and it is not dependent upon specimen size after normalization.
KW - A. Fabrics/textiles
KW - B. Mechanical properties
KW - B. Stress/strain curves
KW - C. Deformation
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U2 - 10.1016/j.compscitech.2012.10.012
DO - 10.1016/j.compscitech.2012.10.012
M3 - Article
AN - SCOPUS:84870181673
SN - 0266-3538
VL - 74
SP - 121
EP - 130
JO - Composites Science and Technology
JF - Composites Science and Technology
ER -