An investigation on shear properties of woven fabrics by bias-extension test

2020 ◽  
pp. 1-9
Author(s):  
R. Befru Büyükbayraktar
Keyword(s):  
Woven Fabrics ◽  
Shear Properties ◽  
Bias Extension Test ◽  
Bias Extension

scholarly journals Bias extension test on an unbalanced woven composite reinforcement: Experiments and modeling via a second-gradient continuum approach

2016 ◽  
Vol 51 (2) ◽  
pp. 153-170 ◽  
Author(s):  
Gabriele Barbagallo ◽  
Angela Madeo ◽  
Ismael Azehaf ◽  
Ivan Giorgio ◽  
Fabrice Morestin ◽  
...  
Keyword(s):  
Constitutive Expression ◽  
Woven Fabrics ◽  
Woven Composite ◽  
Plane Shear ◽  
Second Gradient ◽  
Proposed Model ◽  
Bias Extension Test ◽  
Bias Extension ◽  
Deformation Patterns ◽  
Second Gradient Continuum

The classical continuum models used for the woven fabrics do not fully describe the whole set of phenomena that occur during the testing of those materials. This incompleteness is partially due to the absence of energy terms related to some microstructural properties of the fabric and, in particular, to the bending stiffness of the yarns. To account for the most fundamental microstructure-related deformation mechanisms occurring in unbalanced interlocks, a second-gradient, hyperelastic, initially orthotropic continuum model is proposed. A constitutive expression for the strain energy density is introduced to account for (a) in-plane shear deformations, (b) highly different bending stiffnesses in the warp and weft directions, and (c) fictive elongations in the warp and weft directions which eventually describe the relative sliding of the yarns. Numerical simulations which are able to reproduce the experimental behavior of unbalanced carbon interlocks subjected to a bias extension test are presented. In particular, the proposed model captures the macroscopic asymmetric S-shaped deformation of the specimen, as well as the main features of the associated deformation patterns of the yarns at the mesoscopic scale.

scholarly journals The influence of yarn fineness and number of yarn layers on in-plane shear properties of 3-D woven fabric

2020 ◽  
Vol 29 ◽  
pp. 2633366X1989792
Author(s):  
Liuxiang Guan ◽  
Jialu Li ◽  
Ya’nan Jiao
Keyword(s):  
Image Correlation ◽  
Woven Fabric ◽  
Weft Yarn ◽  
Warp Yarn ◽  
Plane Shear ◽  
Shear Properties ◽  
Bias Extension Test ◽  
Application Potential ◽  
Large Application ◽  
Bias Extension

The 3-D layer-to-layer angle-interlock woven fabric (LLAIWF) has good deformability on a complicated contour, which offers them a large application potential in the field of aerospace. This article mainly focuses on the influence of yarn fineness and number of yarn layers on in-plane shear properties of 3-D LLAIWF during bias extension. Two methods of varying the thickness of 3-D LLAIWF were designed: changing yarn fineness and changing the number of yarn layers. The deformation mechanism of LLAIWF in bias-extension test was analyzed. The effects of two methods on in-plane shear deformation were compared and analyzed. In addition to the data processing on the experimental curve, digital image correlation analysis was conducted on the test photographs, from which shear angles in different area shear angle were measured. The mesostructure of fabric during the bias-extension test was observed. The effect of decreasing yarn layers on the mesostructure of fabric was observed by cutting fabric. The results demonstrated that the yarn fineness and the number of yarn layers play a key role in the in-plane shear properties of 3-D LLAIWF. In addition, the changing of fabric thickness causes that the deformation is asymmetrical. The effect of warp yarn fineness is similar to that of weft yarn fineness during the bias-extension test. Reducing the internal yarns of the fabric created a gap, where the yarns were reduced. This gap will affect the deformability of the fabric.

Formability Evaluation of Non-Crimp Carbon Fabric by Non-Contact 3D Deformation Measurement System

2012 ◽  
Vol 525-526 ◽  
pp. 493-496
Author(s):  
Kazuto Tanaka ◽  
Kazuya Kanazawa ◽  
Shinichi Enoki ◽  
Tsutao Katayama
Keyword(s):  
Measurement System ◽  
Woven Fabrics ◽  
Shear Angle ◽  
Deformation Measurement ◽  
Evaluation Index ◽  
Regular Tetrahedron ◽  
Carbon Fabric ◽  
Bias Extension Test ◽  
3D Deformation ◽  
Bias Extension

Non-Crimp Carbon Fabric (NCF) consists of unidirectional plies which are kept together by stitching yarns arranged in a number of different orientations relative to the fabric production direction. It is reported that NCF possesses excellent drape performance compared to woven fabrics. However there is not a clear criterion of a drape evaluation on the drape characteristic of the NCF. In addition, it is not clarify that stitch pattern and stitch tension influence on the drape characteristic of the NCF. Moreover, in existing bias extension test, measurement of shear angle is based on the pin-jointed net (PJN) approximation. The PJN approximation doesnt takes into consideration the fiber sliding and the effect of the stitched parameters of the NCF. In this study, the bias extension test based on the measurement of shear angle by non-contact 3D deformation measurement system was conducted to evaluate the drape performance of the NCF. We made a proposal of the formability evaluation index based on the measurement results. Moreover, the 3D draping tests were conducted onto hemisphere geometry and regular tetrahedron, in order to verify availability of the formability evaluation index. The availability of the formability evaluation index was verified.

Analysis of Non-Crimp Fabric Composite Reinforcements Forming

2012 ◽  
Vol 504-506 ◽  
pp. 219-224
Author(s):  
Sylvain Bel ◽  
Nahiene Hamila ◽  
Philippe Boisse
Keyword(s):  
Shear Stiffness ◽  
Middle Surface ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Shear Behaviour ◽  
Fabric Reinforcement ◽  
Fabric Composite ◽  
Bias Extension Test ◽  
Bias Extension ◽  
Composite Reinforcements

Abstract Two experimental devices are used for the analysis of the deformation mechanisms of biaxial non-crimp fabric composite reinforcements during preforming. The bias extension test, commonly use for the shear behaviour characterisation of woven fabrics, allows to highlight the sliding between the two plies of the reinforcement. This sliding is localized in areas of high gradient of shearing. This questions the use of bias extension test in determining the shear stiffness of the studied reinforcement. Then a hemispherical stamping experiment, representative of a preforming process, allows to quantify this sliding. The slippage is defined as the distance, projected onto the middle surface, of two points initially opposed on both sides of the reinforcement. For both experiments, the characteristic behavior of the non-crimp fabric reinforcement is highlighted by comparison with a woven textile reinforcement. This woven fabric presents only a very little sliding between warp and weft yarns during preforming. This aspect of the deformation kinematics of the non-crimp fabric reinforcement must be considered when simulating the preforming.

Sign in / Sign up

Export Citation Format

Share Document