Anisotropic Elastic-Plastic Mechanical Properties of Thermally Bonded Bicomponent Fibre Nonwovens

2010 ◽  
Author(s):  
Emrah Demirci ◽  
Memis¸ Acar ◽  
Behnam Pourdeyhimi ◽  
Vadim V. Silberschmidt
Keyword(s):  
Mechanical Properties ◽  
Tensile Tests ◽  
Woven Fabrics ◽  
Core Material ◽  
Random Orientation ◽  
Elastic Plastic ◽  
Nonwoven Fabrics ◽  
Anisotropic Elastic ◽  
Manufacturing Parameters ◽  
Fibre Matrix

Having a unique structure, nonwoven fabrics possess distinct mechanical properties dissimilar to those of woven fabrics and composites. Anisotropic elastic-plastic mechanical properties of core/sheath type thermally bonded bicomponent fibre nonwoven textiles are computed based on manufacturing parameters and fibre properties. Initially, tensile tests are performed on nonwoven fabrics and their single fibres to assess their mechanical behaviour and obtain input parameters for the developed algorithms. Random orientation of individual fibres is introduced into the model in terms of the orientation distribution function (ODF). An algorithm, based on the Hough transform, is developed to determine the ODF and calculate the structure’s anisotropy. The nonwoven fabric is modelled as an assembly of two regions — bond points and a fibre matrix, having distinct mechanical properties. Bond points are treated as a deformable bicomponent composite material composed of the sheath material of fibres as matrix reinforced with the core material as fibres with random orientation of reinforcement. On the other hand, the fibre matrix is treated as a composite membrane structure having low stiffness in thickness direction. A second algorithm is developed to calculate anisotropic material properties of these regions based on fibre characteristics and manufacturing parameters; it can be used in numerical modelling as well as product development and optimization of nonwovens.

scholarly journals Dynamic Response of Thermally Bonded Bicomponent Fibre Nonwovens

2011 ◽  
Vol 70 ◽  
pp. 405-409 ◽  
Author(s):  
Emrah Demirci ◽  
Memiş Acar ◽  
Behnam Pourdeyhimi ◽  
Vadim V. Silberschmidt
Keyword(s):  
Mechanical Properties ◽  
Dynamic Response ◽  
Fibre Diameter ◽  
Orientation Distribution ◽  
Nonwoven Fabric ◽  
Woven Fabrics ◽  
Core Material ◽  
Finite Element Software ◽  
Anisotropic Mechanical Properties ◽  
Fibre Matrix

Having a unique microstructure, nonwoven fabrics possess distinct mechanical properties, dissimilar to those of woven fabrics and composites. This paper aims to introduce a methodology for simulating a dynamic response of core/sheath-type thermally bonded bicomponent fibre nonwovens. The simulated nonwoven fabric is treated as an assembly of two regions with distinct mechanical properties. One region - the fibre matrix – is composed of non-uniformly oriented core/sheath fibres acting as link between bond points. Non-uniform orientation of individual fibres is introduced into the model in terms of the orientation distribution function in order to calculate the structure’s anisotropy. Another region – bond points – is treated in simulations as a deformable bicomponent composite material, composed of the sheath material as its matrix and the core material as reinforcing fibres with random orientations. Time-dependent anisotropic mechanical properties of these regions are assessed based on fibre characteristics and manufacturing parameters such as the planar density, core/sheath ratio, fibre diameter etc. Having distinct anisotropic mechanical properties for two regions, dynamic response of the fabric is modelled in the finite element software with shell elements with thicknesses identical to those of the bond points and fibre matrix.

Mechanical properties of PVDF-coated fabric under tensile tests

2015 ◽  
Vol 35 (4) ◽  
pp. 377-390 ◽  
Author(s):  
Andrzej Ambroziak
Keyword(s):  
Mechanical Properties ◽  
Polyvinylidene Fluoride ◽  
Cyclic Load ◽  
Tensile Tests ◽  
Woven Fabrics ◽  
Uniaxial Tensile ◽  
Cyclic Tests ◽  
Comprehensive Investigation ◽  
Coated Fabric ◽  
Coated Fabrics

Abstract This article describes the laboratory tests necessary to identify the mechanical properties of the polyvinylidene fluoride (PVDF)-coated fabrics named Precontraint 1202S and Precontraint 1302S. First, a short survey of the literature concerning the description of coated woven fabrics is presented. Second, the material parameters for PVDF-coated fabrics are specified on the basis of biaxial tensile tests. A comparison of the 1:1 biaxial and the uniaxial tensile tests results is also given. Additionally, biaxial cyclic tests were performed to observe the change of immediate mechanical properties under cyclic load. The article is aimed as an introduction to a comprehensive investigation of the mechanical properties of coated fabrics.

scholarly journals New Numerical Model of Composite Fabric Behaviour: Simulation of Manufacturing of thin Composite Part

2000 ◽  
Vol 9 (3) ◽  
pp. 096369350000900 ◽  
Author(s):  
J.L. Billoet ◽  
A. Cherouat
Keyword(s):  
Mechanical Properties ◽  
Tensile Tests ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Forming Process ◽  
Composite Part ◽  
Initial Shape ◽  
Shaping Process ◽  
Mechanical Approach ◽  
Behaviour Simulation

The present study concerns the modelling of the behaviour of pre-impregnated woven fabric during the forming process. The mechanical approach is based on a mesostructural model. It allows us to take into account the mechanical properties of fibres and resin and the various dominating mode of deformation of woven fabrics during the forming process. Shear and tensile tests of composite fabric specimens are proposed and compared with the experimental results in order to demonstrate the efficiency of our approach. Different numerical simulations and experiments of shaping process have been carried out in order to validate the proposed computational formulation. The various forming parameters examined have included the initial shape of fabric, fibre orientations and viscosity of resin.

Numerical Modelling of Thermally Bonded Nonwovens: Continuous and Discontinuous Approaches

2012 ◽  
Vol 188 ◽  
pp. 164-169 ◽  
Author(s):  
Emrah Demirci ◽  
Xiao Nan Hou ◽  
Memiş Acar ◽  
Behnam Pourdeyhimi ◽  
Vadim V. Silberschmidt
Keyword(s):  
Mechanical Behaviour ◽  
Mechanical Response ◽  
Orientation Distribution ◽  
Random Orientation ◽  
Shell Elements ◽  
Nonwoven Fabrics ◽  
Anisotropic Mechanical Properties ◽  
Composite Microstructure ◽  
Fibre Matrix ◽  
Modelling Approach

Nonwoven fabrics are web structures of randomly-oriented fibres, bonded by means of mechanical, thermal or chemical techniques. This paper focuses on nonwovens manufactured with polymer-based fibres and bonded thermally. During thermal bonding of such fibres, as a hot calender with an engraved pattern contacts the fibre web, bond spots are formed by melting of the polymer material. As a result of this bonding process, a pattern of bond points connected with randomly oriented polymer-based fibres form the nonwoven web. Due to their manufacturing-induced composite microstructure and random orientation of fibres, nonwovens demonstrate a complex mechanical behaviour. Two distinct modelling approaches were introduced to simulate the non-trivial mechanical response of thermally bonded nonwovens based on their planar density. The first modelling approach was developed to simulate the mechanical behaviour of high-density nonwovens, and the respective fabric was modelled with shell elements with thicknesses identical to those of the bond points and the fibre matrix having distinct anisotropic mechanical properties. Random orientation of individual fibres was introduced into the model in terms of the orientation distribution function in order to determine the material’s anisotropy. The second modelling approach was introduced to simulate low-density nonwovens, and it treated the nonwoven media as a structure composed of fibres acting as truss links between bond points.

Statistical Analysis of Tensile Tests Performed on 316L Specimens Manufactured by Directed Energy Deposition

2020 ◽  
Author(s):  
A. P. Iliopoulos ◽  
J. P. Thomas ◽  
J. C. Steuben ◽  
R. Saunders ◽  
J. G. Michopoulos ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Statistical Analysis ◽  
Energy Deposition ◽  
316L Stainless Steel ◽  
Failure Strain ◽  
Bulk Material ◽  
Tensile Tests ◽  
Tension Tests ◽  
Directed Energy ◽  
Manufacturing Parameters

Abstract The present work reports on the results of tension tests conducted on 316L stainless steel specimens extracted out of thin-walled boxes produced by powder jet additive manufacturing. The specimens were minimally processed to study the potential effects of the manufacturing process on the apparent mechanical properties rather than identifying the properties of the resulting bulk material. Statistical analysis is performed and presented in an attempt to identify correlations between the manufacturing parameters and the apparent mechanical properties. The mechanical properties of interest are Young’s modulus, the yield stress (measured at the 0.2% level), the ultimate stress, and the failure strain.

scholarly journals Determination of Anisotropic Mechanical Properties for Materials Processed by Laser Powder Bed Fusion

2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Even W. Hovig ◽  
Amin S. Azar ◽  
Frode Grytten ◽  
Knut Sørby ◽  
Erik Andreassen
Keyword(s):  
Mechanical Properties ◽  
Transversely Isotropic ◽  
Tensile Tests ◽  
Image Correlation ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Inconel 718 Alloy ◽  
Powder Bed ◽  
Anisotropic Mechanical Properties ◽  
Anisotropic Elastic

Improving the success rate in additive manufacturing and designing highly optimized structures require proper understanding of material behaviour. This study proposes a novel experimental method by which anisotropic mechanical properties of additively manufactured materials can be assessed. The procedure is based on tensile testing of flat specimens, manufactured by laser powder bed fusion (LPBF) at different orientations relative to the build plate. In this study, the procedure was applied to the Inconel 718 alloy. Three identical specimen sets were built, each of which received complementary postprocessing treatments. The tensile tests were carried out on specimens with as-built surface finish. Digital image correlation was used to record the strain field evolution on two perpendicular surfaces of the tensile specimens under loading. An optimization algorithm is also proposed for determining the anisotropic elastic constants using only a few tensile test results. It was observed that both build orientation and postprocessing have strong influence on the anisotropic mechanical properties of the material. The effect of microstructure was also investigated and characterised. Consequently, three transversely isotropic compliance matrices were constructed, representing the effect of the different processing conditions.

scholarly journals Influence of Water-Induced Degradation of Polytetrafluoroethylene (PTFE)-Coated Woven Fabrics Mechanical Properties

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 1
Author(s):  
Andrzej Ambroziak ◽  
Paweł Kłosowski
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Water Immersion ◽  
Tensile Tests ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Uniaxial Tensile ◽  
Influence Of Water ◽  
Proper Values ◽  
The Impact

The impact of water-induced degradation on the mechanical properties of the chosen two PTFE-coated, glass threads woven fabrics is investigated in this paper. The paper begins with a survey of literature concerning the investigation and determination of coated woven fabric properties. The authors carried out the uniaxial tensile tests with an application of flat and curved grips to establish the proper values of the ultimate tensile strength and the longitudinal stiffness of groups of specimens treated with different moisture conditions. Despite the water resistance of the main materials used for fabrics manufacturing, the change of the mechanical properties caused by the influence of water immersion has been noticed. The reduction in the tensile strength resulting under waterlogged is observed in the range from 5% to 16% depending on the type of investigated coated woven fabric and direction of weft or warp.

Manufacturing Technique and Mechanical Properties of Environment-Protective Composite Nonwoven Fabrics

2011 ◽  
Vol 287-290 ◽  
pp. 2673-2676 ◽  
Author(s):  
Jia Horng Lin ◽  
An Pang Chen ◽  
Jan Yi Lin ◽  
Ting An Lin ◽  
Ching Wen Lou
Keyword(s):  
Mechanical Properties ◽  
Nonwoven Fabric ◽  
Ecological Environment ◽  
International Economy ◽  
Nonwoven Fabrics ◽  
Needle Punching ◽  
Recycled Fiber ◽  
Lyocell Fiber ◽  
Composite Nonwoven ◽  
Manufacturing Parameters

Ecological environment deteriorates drastically and rapidly, which can be ascribed to the fast advancement of international economy and technique. Hence, people become green consumers, using green products. The series of lyocell fiber, called as recycled fiber, has been pervasively used. This study used Tencel® fiber, Polylactic Acid (PLA) fiber and high absorbent fiber as well as nonwoven manufacturing, creating Tencel®/PLA/HAF composite nonwoven fabrics. Among the manufacturing parameters, an increase in Tencel® fiber ratio, needle-punching density and basis weight all contributed to heighten the mechanical properties of nonwoven fabrics. In particular, the Tencel®/PLA/HAF composite nonwoven fabric exhibited an optimum tensile strength of 68.8 N and bursting strength of 193.7 N when Tencel® fiber ratio was over 80 wt%, basis weight was 200 g/m2 and needle-punching density was 300 needle/cm2.

scholarly journals Development and Multiscale Characterization of 3D Warp Interlock Flax Fabrics with Different Woven Architectures for Composite Applications

Fibers ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 15 ◽  
Author(s):  
Henri Lansiaux ◽  
Damien Soulat ◽  
François Boussu ◽  
Ahmad Rashed Labanieh
Keyword(s):  
Mechanical Properties ◽  
Natural Fibers ◽  
Three Dimensional ◽  
Tensile Tests ◽  
Woven Fabrics ◽  
Flax Fiber ◽  
Raw Material ◽  
Mechanical Tensile

Multiscale characterization of the textile preform made of natural fibers is an indispensable way to understand and assess the mechanical properties and behavior of composite. In this study, a multiscale experimental characterization is performed on three-dimensional (3D) warp interlock woven fabrics made of flax fiber on the fiber (micro), roving (meso), and fabric (macro) scales. The mechanical tensile properties of the flax fiber were determined by using the impregnated fiber bundle test. The effect of the twist was considered in the back-calculation of the fiber stiffness to reveal the calculation limits of the rule of mixture. Tensile tests on dry rovings were carried out while considering different twist levels to determine the optimal amount of twist required to weave the flax roving into a 3D warp interlock. Finally, at fabric-scale, six different 3D warp interlock architectures were woven to understand the role of the architecture of binding rovings on the mechanical properties of the dry 3D fabric. The results reveal the importance of considering the properties of the fiber and roving at these scales to determine the more adequate raw material for weaving. Further, the characterization of the 3D woven structures shows the preponderant role of the binding roving on their structural and mechanical properties.

scholarly journals Effects of the Infill Density on the Mechanical Properties of Nylon Specimens Made by Filament Fused Fabrication

Technologies ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 57 ◽  
Author(s):  
Svetlana Terekhina ◽  
Innokentiy Skornyakov ◽  
Tatiana Tarasova ◽  
Sergei Egorov
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Additive Manufacturing ◽  
Tensile Tests ◽  
Strength Characteristics ◽  
Fused Filament Fabrication ◽  
Filling Degree ◽  
The Past ◽  
The Relationship ◽  
Manufacturing Parameters

Additive manufacturing of polymer products over the past decade has become widespread in various areas of industry. Using the fused filament fabrication (FFF) method, one of the most technologically simple methods of additive manufacturing, it is possible to produce parts from a large number of different materials, including wear-resistant nylon. The novelty of the work is properties investigation of ±45° filling configuration with different filling degree for nylon, as well as calculating the effect of infill on the strength characteristics, excluding the shell. This article reflects the process of manufacturing samples from nylon using FFF technology with various internal topologies, as well as tensile tests. The analysis of the obtained results is performed and the relationship between the structure of the sample and the limit of its strength is established. To calculate real filling degree and the effect of internal filling on the strength characteristics of the specimen, it is proposed to use a method based on the geometric and mass parameters. The FFF method is promising for developing methods for producing a composite material. The results of this article can be useful in choosing the necessary manufacturing parameters.

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