Slip-Bias Extension test: a characterization tool for understanding and modeling the effect of clamping conditions in forming of woven fabrics

2021 ◽  
pp. 113529
Author(s):  
A. Rashidi ◽  
H. Montazerian ◽  
A.S. Milani

2016 ◽  
Vol 51 (2) ◽  
pp. 153-170 ◽  
Author(s):  
Gabriele Barbagallo ◽  
Angela Madeo ◽  
Ismael Azehaf ◽  
Ivan Giorgio ◽  
Fabrice Morestin ◽  
...  

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.





2012 ◽  
Vol 525-526 ◽  
pp. 493-496
Author(s):  
Kazuto Tanaka ◽  
Kazuya Kanazawa ◽  
Shinichi Enoki ◽  
Tsutao Katayama

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.



2012 ◽  
Vol 504-506 ◽  
pp. 219-224
Author(s):  
Sylvain Bel ◽  
Nahiene Hamila ◽  
Philippe Boisse

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.



Author(s):  
I. Giorgio ◽  
U. Andreaus ◽  
D. Scerrato


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
F. Abdiwi ◽  
P. Harrison ◽  
W. R. Yu

An approach to incorporate the coupling between the shear compliance and in-plane tension of woven engineering fabrics, in finite-element-based numerical simulations, is described. The method involves the use of multiple input curves that are selectively fed into a hypoelastic constitutive model that has been developed previously for engineering fabrics. The selection process is controlled by the current value of the in-plane strain along the two fibre directions using a simple algorithm. Model parameters are determined from actual experimental data, measured using the Biaxial Bias Extension test. An iterative process involving finite element simulations of the experimental test is used to normalise the test data for use in the code. Finally, the effectiveness of the method is evaluated and shown to provide qualitatively good predictions.



Sign in / Sign up

Export Citation Format

Share Document