On the validity of bias-extension test method for the characterisation of in-plane shear properties of rapid-cure prepregs

2020 ◽  
Vol 246 ◽  
pp. 112399
Author(s):  
M.A. Khan ◽  
C. Pasco ◽  
N. Reynolds ◽  
K.N. Kendall
Keyword(s):  
Test Method ◽  
Plane Shear ◽  
Shear Properties ◽  
Bias Extension Test ◽  
Bias Extension ◽  
Rapid Cure

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.

scholarly journals The bias-extension test for the analysis of in-plane shear properties of textile composite reinforcements and prepregs: a review

2016 ◽  
Vol 10 (4) ◽  
pp. 473-492 ◽  
Author(s):  
P. Boisse ◽  
N. Hamila ◽  
E. Guzman-Maldonado ◽  
A. Madeo ◽  
G. Hivet ◽  
...  
Keyword(s):  
Textile Composite ◽  
Plane Shear ◽  
Shear Properties ◽  
Bias Extension Test ◽  
Bias Extension ◽  
Composite Reinforcements

Experimental and finite element analysis of in-plane shear properties of a carbon non-crimp fabrics at macroscopic scale

2017 ◽  
Vol 52 (2) ◽  
pp. 235-244 ◽  
Author(s):  
Samir Deghboudj ◽  
Wafia Boukhedena ◽  
Hamid Satha
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Elastic Model ◽  
Macroscopic Scale ◽  
Element Analysis ◽  
Plane Shear ◽  
Shear Properties ◽  
Bias Extension Test ◽  
Bias Extension ◽  
Composite Reinforcement

Shear deformation of composite reinforcement is the most significant and important mechanism of material characterization. So, in-plane shear properties of composite reinforcement are important parameters for determining application and use of this category of materials. The bias extension test is frequently employed to investigate the in-plane shear behavior of composites fabrics with a length equal to or greater than twice its width. In the first part of this work, bias extension tests on non-crimp fabrics have been conducted. Force and displacement were measured and registered. From obtained data, shear angles and normalized shear forces were theoretically determined. The second part was a finite element analysis of the same test based on hypo elastic model at macroscopic scale. The software ABAQUS/Explicit was used to carry out the finite element analysis in the work.

SHEAR PROPERTY OF STRUCTURAL EPOXY ADHESIVE EXPOSED TO TROPICAL WEATHERING CONDITION

2015 ◽  
Vol 77 (8) ◽  
Author(s):  
Shukur Abu Hassan ◽  
Yob Saed Ismail ◽  
Abdul Rahman Mohd. Sam ◽  
Umar Abdul Hanan ◽  
Mat Uzir Wahit
Keyword(s):  
Structural Integrity ◽  
Elevated Temperatures ◽  
Salt Water ◽  
Epoxy Adhesive ◽  
Test Method ◽  
Plain Water ◽  
Plane Shear ◽  
Shear Properties ◽  
Shear Property ◽  
Epoxy Material

As a consequence of tropical climate featuring abundant rain and sunshine throughout the year, adhesive bonded joints undergo substantial exposure to moisture and elevated temperatures. It is known that the degradation of adhesive materials such as structural epoxy due to weathering could affect the overall bond performance of structural integrity of reinforced concrete such as carbon fibre reinforced polymer composites (CFRP) plate system. The objective of the study is to investigate the in-plane shear properties of structural epoxy material exposed to tropical environmental conditions using Arcan Test Method. The epoxy adhesive was casted in a closed metal mould to produce butterfly shaped specimens. The specimens were exposed to four conditions; laboratory, outdoor, plain water, and salt water. The specimens were tested for shear properties and failed in brittle form. Microstructure analysis was performed to study the fracture surface of the test specimens. The study showed that the tropical exposure conditions influenced the shear strength of the epoxy material, especially for those exposed to plain and salt water conditions, which were 32% lower than the control specimen for specimens exposed to plain water followed by salt water (26.6%), laboratory (25.4%) and finally outdoor (18.4%).

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.

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