Dynamic Tensile Testing of Kevlar 49 Fabrics

Measurement of deformation history during a high-speed mechanical test plays an important role in establishing the dynamic behavior of materials. Traditional strain measuring techniques such as extensometers and strain gauges have limitations such as frequency response and range of strain. Kevlar 49 fabrics were tested in tension within a strain-rate range of 25 to 170  s-1 using a high-speed servohydraulic testing system. Results show that the dynamic material properties in terms of Young’s modulus, tensile strength, maximum strain, and toughness increase with increasing strain rate. The woven nature of Kevlar 49 fabric results in large displacements and shape changes during tests. Noncontacting strain measuring technique is therefore highly preferred. A technique was developed using image analysis to obtain the deformation of Kevlar 49 fabrics at the tested strain rates. Using image analysis results, the stress-strain curves of Kevlar 49 fabrics at different strain rates were constructed and compared wi...

[1]  Susan I. Hill,et al.  Practical Considerations in Determining High Strain Rate Material Properties , 1998 .

[2]  K. G. Hoge.  Influence of strain rate on mechanical properties of 6061-T6 aluminum under uniaxial and biaxial states of stress , 1966 .

[3]  Image Analysis of Kevlar 49 Fabric at High Strain Rate , 2008 .

[4]  Deju Zhu,et al.  Dynamic tensile testing of fabric–cement composites , 2011 .

[5]  Yang Wang,et al.  The effects of strain rate on the mechanical behaviour of kevlar fibre bundles: an experimental and theoretical study , 1998 .

[6]  H. Wagner,et al.  Dependence of the tensile strength of pitch-based carbon and para-aramid fibres on the rate of strain , 1990, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[7]  J. L. Thorpe,et al.  Image analysis to measure strain in wood and paper , 1991, Wood Science and Technology.

[8]  M. Bolduc,et al.  Study of parameters affecting the strength of yarns , 2006 .

[9]  T. Nicholas.  Tensile testing of materials at high rates of strain , 1981 .

[10]  M. J. Forrestal,et al.  A split Hopkinson pressure bar technique to determine compressive stress-strain data for rock materials , 2001 .

[11]  C. Burgoyne,et al.  Statistical variability in the strength and failure strain of aramid and polyester yarns , 1994 .

[12]  Ahmet H. Aydilek,et al.  USE OF IMAGE ANALYSIS IN DETERMINATION OF STRAIN DISTRIBUTION DURING GEOSYNTHETIC TENSILE TESTING , 2004 .

[13]  Deju Zhu,et al.  Low velocity flexural impact behavior of AR glass fabric reinforced cement composites , 2009 .

[14]  C. Ruiz,et al.  Dynamic testing of ceramics under tensile stress , 1995 .

[15]  Xinran Xiao,et al.  Dynamic tensile testing of plastic materials , 2008 .

[16]  Fodil Meraghni,et al.  Experimental methodology for high strain-rates tensile behaviour analysis of polymer matrix composites , 2005 .

[17]  J. Bell.  On the direct measurement of very large strain at high strain rates , 1967 .

[18]  M. Meyers.  Dynamic Behavior of Materials , 1994 .

[19]  Howard Kuhn,et al.  Mechanical testing and evaluation , 2000 .

[20]  B. Zagar,et al.  Noncontacting strain measurements at high temperatures by the digital laser speckle technique , 2000 .

[21]  Barzin Mobasher,et al.  High speed tensile behavior of sisal fiber cement composites , 2010 .

[22]  Ming Cheng,et al.  Mechanical Properties of Kevlar® KM2 Single Fiber , 2005 .

[23]  Noncontacting strain measurements during tensile tests , 1996 .

[24]  Herman DeWeerd,et al.  Non-Contact Laser Extensometer , 1987, Photonics West - Lasers and Applications in Science and Engineering.

[25]  Barzin Mobasher,et al.  Modeling of multilayer composite fabrics for gas turbine engine containment systems , 2006 .

[26]  Optical measurement of the specimen deformation at high strain rate , 2004 .

[27]  D. Matlock,et al.  Assessment of the Strain-Rate Dependent Tensile Properties of Automotive Sheet Steels , 2004 .

[28]  V. Sánchez Gálvez,et al.  Dynamic tensile testing of aramid and polyethylene fiber composites , 1997 .

[29]  M. J. Forrestal,et al.  A split Hopkinson bar technique for low-impedance materials , 1999 .

[30]  Peter Schwartz,et al.  A Study of Statistical Variability in the Strength of Single Aramid Filaments , 1984 .