Simulation of plate compression behavior of warp-knitted spacer fabrics based on geometry and property parameters

2018 ◽  
Vol 89 (6) ◽  
pp. 1051-1064 ◽  
Author(s):  
Fengxin Sun ◽  
Mingying Ma ◽  
Xingxing Pan ◽  
Gui Liu ◽  
Shu Yang ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Three Dimensional ◽  
Strain Curve ◽  
Dimensional Structure ◽  
Bending Angle ◽  
Compression Behavior ◽  
Compression Property ◽  
Spacer Fabric ◽  
Spacer Fabrics

The plate compression property of warp-knitted spacer fabrics greatly determines their industrial application in cushions and mattresses, which can be regulated by the structure and property of spacer filaments of spacer fabrics. To better meet application requirements, this paper detailed a study on the relationships between the geometry and property parameters of spacer filaments and the plate compression property of spacer fabrics. A three-dimensional structure model was firstly developed using the finite element method based on a typical spacer fabric. The model shows a satisfactory prediction of the compression force–strain curve of the spacer fabric compared with the corresponding experimental curve. Consequently, the effects of geometry parameters, including height, diameter, arrangement density and bending angle of spacer filaments, and Young’s modulus of the filaments on the compression behavior of spacer fabrics were investigated using the validated model by adjusting the corresponding geometry and property parameters. The stress nephogram and stress distribution along the filaments at compression strain 0.6 were analyzed to discover the deformation mechanism of spacer filaments under compression. It was found that the spacer fabric with smaller filament height, courser filament diameter, larger bending angle, higher arrangement density and Young’s modulus of filaments had higher compression resistance. This study is useful to optimize the performance of spacer fabrics in design and manufacturing by purposefully tuning the geometry and property parameters.

scholarly journals A NEW TEST METHOD TO MEASURE THE COMPRESSIBILITY OF SPACER FABRICS

2019 ◽  
Vol 2019 ◽  
pp. 140-143
Author(s):  
Musa KILIC ◽  
Gonca BALCI KILIC ◽  
Murat DEMIR ◽  
Gulsah CELIK ◽  
Izzet Onal BUGDUZ ◽  
...  
Keyword(s):  
Shear Deformation ◽  
Three Dimensional ◽  
Test System ◽  
Test Methods ◽  
Test Method ◽  
Dimensional Structure ◽  
Spacer Fabric ◽  
The Difference ◽  
Spacer Fabrics ◽  
Fabric Structures

Spacer fabric is a three-dimensional structure that obtained by the connection of two parallel fabric surfaces with the connection threads. Spacer fabrics are widely used for their several functional advantages that they provide unlike conventional fabrics. Compressibility is one of the important functional parameters for these fabric structures. The compressibility values of the spacer fabrics are measured based on the ISO 3386-1 standard. However, this standard is used for structures that have non-axial shear during compression such as foam, sponge and so on. It is thought that this standard is not suitable for spacer fabric structures due to the shear deformation which occurs during the measurement of compressibility. For this purpose, as in accordance with spacer fabrics end-use area, a new test system been proposed to measure of compressibility that prevents shear during the test. Thus, it is aimed to prevent the shear deformation and the deviant results obtained during the test. Within the scope of the study, the compressibility properties of spacer fabric structures, which have undergone different thicknesses and different finishing processes, were measured according to both ISO 3386-1 and the new proposed test method. When the results were compared, it was observed that the results obtained in the new proposed test setup were higher and the difference between the measured results according to both test methods was statistically significant for α = 0.05.

scholarly journals Reduction in tendon elasticity from unloading is unrelated to its hypertrophy

2010 ◽  
Vol 109 (3) ◽  
pp. 870-877 ◽  
Author(s):  
Ryuta Kinugasa ◽  
John A. Hodgson ◽  
V. Reggie Edgerton ◽  
David D. Shin ◽  
Shantanu Sinha
Keyword(s):  
Achilles Tendon ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Plantar Flexion ◽  
Three Dimensional ◽  
Strain Curve ◽  
Medial Gastrocnemius ◽  
Morphological Properties ◽  
Cross Sectional ◽  
Tendon Stiffness

Tendinous tissues respond to chronic unloading with adaptive changes in mechanical, elastic, and morphological properties. However, little is known about the changes in the detailed structures of the entire tendinous tissue and whether the change in tendon stiffness is related to morphology. We investigated changes in dimensional (volume, cross-sectional area, segmented lengths) and elastic (Young's modulus) properties of the Achilles tendon and distal aponeurosis in response to chronic unilateral lower limb suspension (ULLS) using velocity encoded phase contrast (VE-PC) and three-dimensional morphometric magnetic resonance imaging (MRI). Five healthy subjects underwent ULLS for 4 wk. Axial morphometric MRI was acquired along the entire length from the calcaneous to the medial gastrocnemius insertion. An oblique sagittal VE-PC MRI was also acquired. The Young's modulus could be calculated from this cine dynamic sequence of velocity encoded images from the slope of the stress-strain curve during the submaximal isometric plantar flexion. After 4 wk of ULLS, we found significant (46.7%) decrease in maximum plantar flexion torque. The total volumes of entire tendinous tissue (determined as the sum of the Achilles tendon and distal aponeurosis) increased significantly by 6.4% (11.9 vs. 12.7 ml) after ULLS. In contrast, Young's modulus decreased significantly by 10.4% (211.7 vs. 189.6 MPa) for the Achilles tendon and 29.0% for the distal aponeurosis (158.8 vs. 113.0 MPa) following ULLS. There was no significant correlation between relative change in volume and Young's modulus with 4 wk of ULLS. It is suggested that, although tendon hypertrophy can be expected to adversely affect tendon stiffness, the absence of any significant correlation between the magnitude of tendon hypertrophy and reduced Young's modulus indicates that dimensional factors were not critical to the elastic properties.

scholarly journals Developing a Quantifying Device for Soft Tissue Material Prop-Erties around Lumbar Spines

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 67
Author(s):  
Song Joo Lee ◽  
Yong-Eun Cho ◽  
Kyung-Hyun Kim ◽  
Deukhee Lee
Keyword(s):  
Lumbar Spine ◽  
Soft Tissue ◽  
Young’S Modulus ◽  
Viscoelastic Properties ◽  
Soft Tissues ◽  
Young's Modulus ◽  
Strain Curve ◽  
Stress And Strain ◽  
Commercial Device ◽  
Tissue Material

Knowing the material properties of the musculoskeletal soft tissue could be important to develop rehabilitation therapy and surgical procedures. However, there is a lack of devices and information on the viscoelastic properties of soft tissues around the lumbar spine. The goal of this study was to develop a portable quantifying device for providing strain and stress curves of muscles and ligaments around the lumbar spine at various stretching speeds. Each sample was conditioned and applied for 20 repeatable cyclic 5 mm stretch-and-relax trials in the direction and perpendicular direction of the fiber at 2, 3 and 5 mm/s. Our device successfully provided the stress and strain curve of the samples and our results showed that there were significant effects of speed on the young’s modulus of the samples (p < 0.05). Compared to the expensive commercial device, our lower-cost device provided comparable stress and strain curves of the sample. Based on our device and findings, various sizes of samples can be measured and viscoelastic properties of the soft tissues can be obtained. Our portable device and approach can help to investigate young’s modulus of musculoskeletal soft tissues conveniently, and can be a basis for developing a material testing device in a surgical room or various lab environments.

scholarly journals Effect of Nanopores on Mechanical Properties of the Shape Memory Alloy

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 529
Author(s):  
Chunzhi Du ◽  
Zhifan Li ◽  
Bingfei Liu
Keyword(s):  
Mechanical Properties ◽  
Constitutive Model ◽  
Shape Memory ◽  
Young’S Modulus ◽  
Residual Strain ◽  
Surface Effect ◽  
Young's Modulus ◽  
Strain Curve ◽  
Stress Strain ◽  
Strength Limit

Nanoporous Shape Memory Alloys (SMA) are widely used in aerospace, military industry, medical and health and other fields. More and more attention has been paid to its mechanical properties. In particular, when the size of the pores is reduced to the nanometer level, the effect of the surface effect of the nanoporous material on the mechanical properties of the SMA will increase sharply, and the residual strain of the SMA material will change with the nanoporosity. In this work, the expression of Young’s modulus of nanopore SMA considering surface effects is first derived, which is a function of nanoporosity and nanopore size. Based on the obtained Young’s modulus, a constitutive model of nanoporous SMA considering residual strain is established. Then, the stress–strain curve of dense SMA based on the new constitutive model is drawn by numerical method. The results are in good agreement with the simulation results in the published literature. Finally, the stress-strain curves of SMA with different nanoporosities are drawn, and it is concluded that the Young’s modulus and strength limit decrease with the increase of nanoporosity.

FEM Stress Analysis and Strength of Scarf Adhesive Joints of Similar Adherend Subjected to Impact Tensile Loadings

2007 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Yuya Hirayama ◽  
He Dan
Keyword(s):  
Young’S Modulus ◽  
Principal Stress ◽  
Stress Wave ◽  
Young's Modulus ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
Adhesive Joints ◽  
Stress Wave Propagation ◽  
Adhesive Thickness ◽  
Three Dimensional Finite Element

The stress wave propagation and stress distribution in scarf adhesive joints have been analyzed using three-dimensional finite element method (FEM). The FEM code employed was LS-DYNA. An impact tensile loading was applied to the joint by dropping a weight. The effect of the scarf angle, Young’s modulus of the adhesive and adhesive thickness on the stress wave propagations and stress distributions at the interfaces have been examined. As the results, it was found that the point where the maximum principal stress becomes maximum changes between 52 degree and 60 degree under impact tensile loadings. The maximum value of the maximum principal stress increases as scarf angle decreases, Young’s modulus of the adhesive increases and adhesive thickness increases. In addition, Experiments to measure the strains and joint strengths were compared with the calculated results. The calculated results were in fairly good agreements with the experimental results.

Numerical Modeling of Macroscopic Behavior of Particulate Composite with Crosslinked Polymer Matrix

2011 ◽  
Vol 465 ◽  
pp. 129-132
Author(s):  
Luboš Náhlík ◽  
Bohuslav Máša ◽  
Pavel Hutař
Keyword(s):  
Young’S Modulus ◽  
Polymer Matrix ◽  
Young's Modulus ◽  
Numerical Models ◽  
Strain Curve ◽  
Particulate Composite ◽  
Material Behavior ◽  
Particulate Composites ◽  
Stress Strain ◽  
Crosslinked Polymer

Particulate composites with crosslinked polymer matrix and solid fillers are one of important classes of materials such as construction materials, high-performance engineering materials, sealants, protective organic coatings, dental materials, or solid explosives. The main focus of a present paper is an estimation of the macroscopic Young’s modulus and stress-strain behavior of a particulate composite with polymer matrix. The particulate composite with a crosslinked polymer matrix in a rubbery state filled by an alumina-based mineral filler is investigated by means of the finite element method. A hyperelastic material behavior of the matrix was modeled by the Mooney-Rivlin material model. Numerical models on the base of unit cell were developed. The numerical results obtained were compared with experimental stress-strain curve and value of initial Young’s modulus. The paper can contribute to a better understanding of the behavior and failure of particulate composites with a crosslinked polymer matrix.

Coating agent-induced mechanical behavior of 3D self-assembled nanocrystals

2017 ◽  
Vol 19 (35) ◽  
pp. 23887-23897 ◽  
Author(s):  
Arzu Çolak ◽  
Jingjing Wei ◽  
Imad Arfaoui ◽  
Marie-Paule Pileni
Keyword(s):  
Mechanical Behavior ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Three Dimensional ◽  
Coating Agent ◽  
Self Assembled

The Young's modulus of three-dimensional self-assembled Ag nanocrystals, as so-called supracrystals, is correlated with the type of coating agent as well as the nanocrystal morphology.

scholarly journals Three-dimensional seismic analysis of concrete gravity dams considering foundation flexibility

2021 ◽  
Vol 25 (1) ◽  
pp. 88-98
Author(s):  
Mokhtar Messaad ◽  
Messoud Bourezane ◽  
Mohamed Latrache ◽  
Amina Tahar Berrabah ◽  
Djamel Ouzendja
Keyword(s):  
Young’S Modulus ◽  
Seismic Analysis ◽  
Young's Modulus ◽  
Three Dimensional ◽  
Shear Stresses ◽  
Total System ◽  
Dam Reservoir ◽  
Principal Stresses ◽  
Foundation Soil ◽  
North West

Abstract Concrete dams are considered as complex construction systems that play a major role in the context of both economic and strategic utilities. Taking into account reservoir and foundation presence in modeling the dam-reservoir-foundation interaction phenomenon leads to a more realistic evaluation of the total system behavior. The article discusses the dynamic behavior of dam-reservoir-foundation system under seismic loading using Ansys finite element code. Oued Fodda concrete dam, situated at Chlef, in North-West of Algeria, was chosen as a case study. Parametric study was also performed for different ratios between foundation Young's modulus and dam Young's modulus E f /E d (which varies from 0.5 to 4). Added mass approach was used to model the fluid reservoir. The obtained results indicate that when dam Young's modulus and foundation Young's modulus are equal, the foundation soil leads to less displacements in the dam body and decreases the principal stresses as well as shear stresses.

scholarly journals Knitting Technologies And Tensile Properties Of A Novel Curved Flat-Knitted Three-Dimensional Spacer Fabrics

2015 ◽  
Vol 15 (3) ◽  
pp. 191-197 ◽  
Author(s):  
Xiaoying Li ◽  
Gaoming Jiang ◽  
Xiaolin Nie ◽  
Pibo Ma ◽  
Zhe Gao
Keyword(s):  
Tensile Stress ◽  
Tensile Properties ◽  
Dimensional Stability ◽  
Three Dimensional ◽  
Tensile Tests ◽  
Weft Direction ◽  
Aramid Fibres ◽  
Spacer Fabric ◽  
Fabric Deformation ◽  
Spacer Fabrics

AbstractThis paper introduces a knitting technique for making innovative curved three-dimensional (3D) spacer fabrics by the computer flat-knitting machine. During manufacturing, a number of reinforcement yarns made of aramid fibres are inserted into 3D spacer fabrics along the weft direction to enhance the fabric tensile properties. Curved, flat-knitted 3D spacer fabrics with different angles (in the warp direction) were also developed. Tensile tests were carried out in the weft and warp directions for the two spacer fabrics (with and without reinforcement yarns), and their stress–strain curves were compared. The results showed that the reinforcement yarns can reduce the fabric deformation and improve tensile stress and dimensional stability of 3D spacer fabrics. This research can help the further study of 3D spacer fabric when applied to composites.

Effect of temperature on properties of aluminum/single-walled carbon nanotube nanocomposite by molecular dynamics simulation

2019 ◽  
Vol 234 (2) ◽  
pp. 635-642 ◽  
Author(s):  
Mohsen Motamedi ◽  
AH Naghdi ◽  
SK Jalali
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Carbon Nanotube ◽  
Molecular Dynamics Simulation ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Strain Curve ◽  
Dynamics Simulation ◽  
Effect Of Temperature ◽  
Metal Composite

Composite materials have become popular because of high mechanical properties and lightweight. Aluminum/carbon nanotube is one of the most important metal composite. In this research, mechanical properties of aluminum/carbon nanotube composite were obtained using molecular dynamics simulation. Then, effect of temperature on stress–strain curve of composite was studied. The results showed by increasing temperature, the Young’s modulus of composite was decreased. More specifically increasing the temperature from 150 K to 620 K, decrease the Young’s modulus to 11.7%. The ultimate stress of composite also decreased by increasing the temperature. A continuum model of composite was presented using finite element method. The results showed the role of carbon nanotube on strengthening of composite.

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