Multiscale Finite Element Modeling of the Viscoelastic Behavior of Sportswear Under Periodic Load

2020 ◽  
pp. 0887302X2093779
Author(s):  
Ali Sajjadi ◽  
Seyed Abdolkarim Hosseini ◽  
Saeed Ajeli ◽  
Mohammad Mashayekhi
Keyword(s):  
Finite Element ◽  
Mechanical Behavior ◽  
Viscoelastic Properties ◽  
Viscoelastic Behavior ◽  
Tensile Load ◽  
Periodic Load ◽  
Unit Cells ◽  
Multiscale Finite Element ◽  
Optimum Sample ◽  
Good Agreement

The aim of this study was to investigate the influence of different stitch factors on the mechanical behavior of the seam section of sportswear under periodic load. Multiscale finite element (FE) modeling was then utilized to predict the mechanical behavior of the samples under periodic tensile load. The unit cells of the fabric and the stitched section were modeled in the mesoscale. Elastic and viscoelastic properties of the yarns were assigned to the model. In order to obtain the mechanical properties of the sample, periodic boundary conditions were applied to the unit cell. Elastic and viscoelastic properties calculated from the mesoscale were then used for the macromodel. FE results had a good agreement with the experimental ones in predicting the mechanical behavior of the seam section under the periodic tensile load. By using Taguchi method, the optimum sample was found.

Viscoelastic Properties of Multi Walled Carbon Nanotube/Epoxy Composites at the Different Nanotube Content

2011 ◽  
Vol 13 ◽  
pp. 33-39 ◽  
Author(s):  
Arash Montazeri ◽  
Alireza Khavandi ◽  
Jafar Javadpour ◽  
Abbas Tcharkhtchi
Keyword(s):  
Carbon Nanotube ◽  
Viscoelastic Properties ◽  
Epoxy Composite ◽  
Viscoelastic Behavior ◽  
Molding Process ◽  
Cole Diagram ◽  
Multi Walled Carbon Nanotube ◽  
Viscoelastic Modeling ◽  
Good Agreement ◽  
Properties Of Composites

The viscoelastic properties of composites multi walled carbon nanotube / epoxy at different weight fractions (0.1, 0.5 and 1wt %) were evaluated by performing dynamic mechanical thermal analysis (DMTA) test. The MWCNT/ epoxy composite were fabricated by sonication and a cast molding process. The results showed that addition of nanotubes to epoxy had a significant effect on the viscoelastic properties. However, the use of 0.5wt% increased the viscoelastic properties more significantly. Concerning viscoelastic modeling, the COLE-COLE diagram has been plotted by the result of DMTA tests. These results show a good agreement between the Perez model and the viscoelastic behavior of the composite.

Modeling of Underfilled PBGA Assemblies Using Both Viscoelastic and Elastic Material Properties

2019 ◽  
Author(s):  
Promod R. Chowdhury ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Solder Joint ◽  
Viscoelastic Properties ◽  
Computational Cost ◽  
Viscoelastic Behavior ◽  
Polymer Materials ◽  
Temperature Dependent ◽  
Solder Joint Fatigue ◽  
Underfill Material

Abstract In microelectronics packaging industry, polymer based materials are used extensively. These polymer materials show viscoelastic behavior when subject to time dependent loads or deformations. The viscoelastic behavior highly depends on both temperature and time. In many cases, these viscoelastic properties are often neglected due to saving computational cost or unavailability of full characterization of the viscoelastic properties. To make accurate predictions of packaging mechanical behavior and reliability, it is important to accurately characterize the viscoelastic behavior of mold compounds, underfill encapsulants, adhesives and other polymers used in electronic assemblies. After characterization, these parameters can be used as input material property data for finite element analysis (FEA) simulations. In this study, both frequency dependent dynamic mechanical analysis (DMA) measurements, and strain and temperature dependent stress relaxation experiments were performed on a typical underfill material in order to characterize its linear viscoelastic behavior. In both cases, a master curve was determined using the assumption of time-temperature equivalence, and Prony series expansions were utilized to model the underfill material relaxation behavior. After that, these viscoelastic underfill material parameters were used in finite element models of underfilled ball grid array packages (Ultra CSP) subjected to thermal cycling from −40 to 125 °C. Separate simulations were also performed using temperature dependent elastic properties for the underfill material. In both cases, the solder joint fatigue life was estimated, and the effects of using viscoelastic properties for the underfill in solder joint fatigue life simulation were investigated.

Finite-element stress analysis of a non-linear problem: A connecting-road eye loaded by means of a pin

1970 ◽  
Vol 5 (1) ◽  
pp. 41-48 ◽  
Author(s):  
D J White ◽  
L R Enderby
Keyword(s):  
Finite Element ◽  
Stress Analysis ◽  
Linear Problem ◽  
Tensile Load ◽  
Strain Gauges ◽  
Connecting Rod ◽  
Linear Elastic ◽  
Plane Stress Problem ◽  
Non Linear ◽  
Good Agreement

The stress analysis of a connecting rod under a tensile load represents a non-linear problem, since the distribution of the forces, acting between the eye of the rod and the pin, changes as the loading proceeds. This is due to the tendency of the eye to deform, thus wrapping itself around the pin as the clearance between the parts is reduced. In consequence, the stress pattern in the eye also changes. Such a problem has been solved with a linear elastic finite-element computer programme. A connecting-rod eye was idealized as a plane-stress problem and special elements were introduced to connect the pin and rod together. These elements were assigned stiffnesses which were changed in a prescribed manner after each iteration until compatibility of forces and displacements, with due allowance for initial clearances, was obtained at each connecting point. Although eight iterations were required to achieve the correct displacements, it was found that the circumferential stresses did not change appreciably after the first few iterations. Good agreement was found between the calculated stresses and those measured in a laboratory test with electrical-resistance strain gauges.

Experiment and Finite Element Analysis of Partially Prestressed with Non-Bonded Fiber Reinforcement Polymer Tendon under Four Points

2013 ◽  
Vol 838-841 ◽  
pp. 416-423
Author(s):  
Ya Min Yi ◽  
Dong Hui Cheng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Carbon Fiber ◽  
Mechanical Behavior ◽  
Concrete Beams ◽  
Fiber Reinforcement ◽  
Element Analysis ◽  
Concrete Members ◽  
Carbon Fiber Reinforcement ◽  
Good Agreement

Carbon fiber reinforcement polymer could be used to replace steel tendon to bear loads together with concrete to solve the problem of steel tendon corrosion in concrete members. To study mechanical behavior of this kind of member, four concrete beams of partially prestressed with non-bonded carbon fiber reinforcement tendon were fabricated. In these beams, the reinforcement was taken as non prestressed tendon and carbon fiber reinforcement polymer tendon was taken as non-bonded prestressed tendon. Four points bending experiment were completed. Then the mechanical behavior of these beams has been studied through finite element analysis. The results show that a good agreement between experimental and finite element analysis results.

Quasi-static and Oscillatory Indentation in Linear Viscoelastic Solids

2007 ◽  
Vol 1049 ◽  
Author(s):  
Yang-Tse Cheng ◽  
Che-Min Cheng
Keyword(s):  
Mechanical Behavior ◽  
Viscoelastic Properties ◽  
Viscoelastic Behavior ◽  
Small Scale ◽  
Instrumented Indentation ◽  
Viscoelastic Solids ◽  
Linear Viscoelastic ◽  
Soft Matters

AbstractInstrumented indentation is often used in the study of small-scale mechanical behavior of “soft” matters that exhibit viscoelastic behavior. A number of techniques have been used to obtain the viscoelastic properties from quasi-static or oscillatory indentations. This paper summarizes our recent findings from modeling indentation in linear viscoelastic solids. These results may help improve methods of measuring viscoelastic properties using instrumented indentation techniques.

Multiscale finite-element modelling of the electrical conductivity of polyvinylchloride–nickel composites

2018 ◽  
Vol 53 (9) ◽  
pp. 1255-1260
Author(s):  
Abdulrahman A Alghamdi ◽  
Hamzah A Alharthi
Keyword(s):  
Electrical Conductivity ◽  
Finite Element ◽  
Finite Element Modelling ◽  
Unit Cell ◽  
Element Modelling ◽  
Electrical Conductivities ◽  
Polymer Metal ◽  
Multiscale Finite Element ◽  
Nickel Composites ◽  
Good Agreement

The electrical properties of polymer–metal composites are strongly affected by the quantity, distribution, and arrangement of the metal particles in the polymer matrix. The effect of these factors was investigated in a polyvinylchloride–nickel composite by adopting a multiscale finite-element modelling approach. Modelling in the macroscale was used to determine the electrical conductivity of agglomerated particles with varying volume fractions of Ni. The calculated electrical conductivities were then incorporated into calculations on the microscale, using a composite unit cell. The electrical conductivity of the composite unit cell was in good agreement with experimental data.

Investigation on the Tensile Strength of GLARE Laminate with a Hole

2014 ◽  
Vol 1052 ◽  
pp. 358-366 ◽  
Author(s):  
Gui Min Qu ◽  
Bo Ru Li ◽  
Li Zhao ◽  
Xiao Feng Li
Keyword(s):  
Finite Element ◽  
Tensile Strength ◽  
Tensile Load ◽  
Element Model ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
Glass Fiber Reinforced ◽  
The Finite Element Analysis ◽  
Good Agreement

As for the case of tensile plastic deformation of glass fiber reinforced aluminum laminates (GLARE), the finite element analysis model of the tensile strength of GLARE laminates with a hole is established by means of ABAQUS software under tensile load. The modeling is found to be in good agreement between the simulation results and the experiment data in the failure strength. On the basis of the finite element model, the tensile strength of GLARE laminates containing a hole in other ply modes is simulated, and the influences of the hole size and ply angle on the tensile strength are given in this paper.

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