Determining Pseudo Poisson’s Ratio of Woven Fabric with a Digital Image Correlation Method

Abstract

In this paper the determination of pseudo Poisson’s ratio of woven fabric with a digital image correlation method is presented. Measurements were performed on three cotton woven fabric samples which were prepared according the standard ISO 13934-1:1999. The fabric sample was exposed to tensile loading of 1% strain on a tensile test machine. Testing was simultaneous recording with a digital video camera. These video recordings were afterwards processed in the MATLAB program and the pseudo Poisson’s ratio determined according to the displacement in the x and y axis directions. The pseudo Poisson’s ratio was determined for three woven fabrics in the warp and weft directions. The results of the investigation show that the values of the pseudo Poisson’s ratio are in the range from 0.2 to 0.5, which agrees with results also found in the literature. According to the investigation it can be concluded that the value of the pseudo Poisson’s ratio depends on the weave type and the number of yarns in the fabric. For woven fabric in plain weave a higher pseudo Poisson’s ratio is determined (warp direction from 0.335 to 0.500, weft direction from 0.392 to 0.484). The pseudo Poisson’s ratio for woven fabric in twill weave has values in the warp direction from 0.281 to 0.329, and in the weft direction from 0.183 to 0.214.

Mechanical properties of reinforced composite materials under uniaxial and planar tension loading regimes measured using a non-contact optical method

“…Use of equation 8provides a useful check on the validity of the experimental data and although the two methods produced different values for ν weft and for ν warp , they were considered to be within the margin of experimental error. Furthermore, literature values for ν lying in the range of 0.2 to 0.5 for similar materials to those contained within the composite bracket the measured values obtained in this study (Hursa et al, 2009;Kraft, et al, 2014).…”

Through-thickness permeability modelling of woven fabric under out-of-plane deformation

“…Its slope divided by L (assumed constant) was the fabric E value with a unit Pa. In Fig.7 An attempt was made to measure v values of the two fabrics using Digital Image Correlation (DIC) equipment according to Hursa's approach [16], however the results showed both larger than 1 which is not considered physically realistic. In the next section, a few v values will be used to assess sensitivity.…”

“…The prediction is based on Eq.24a, assuming three values (0.2, 0.3 & 0.4) in the range for woven fabric [16,19]. The comparisons of ' between predictions ('Pred' curves) and measurements ('EXPT' dots) are shown in Fig.8.…”

Weft-knitted auxetic textile design

“…The measurement process aims to combine elements of interest from different disciplinary areas. This includes variations on techniques used by Liu et al , Hu et al , BSI and Hursa et al , by setting up a standardised test frame. This uses a 100 mm squared area and then extends in the frame by 10 mm each time.…”