scholarly journals Challenges in developing of 3D nonlinear viscoelastic models

2021 ◽  
Vol 1190 (1) ◽  
pp. 012005
Author(s):  
Liva Pupure ◽  
Leonids Pakrastins ◽  
Janis Varna
Keyword(s):  
Viscoelastic Models ◽  
Nonlinear Viscoelastic

Identification of Nonlinear Viscoelastic Models of Flexible Polyurethane Foam From Uniaxial Compression Data

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
Yousof Azizi ◽  
Patricia Davies ◽  
Anil K. Bajaj
Keyword(s):  
Uniaxial Compression ◽  
Viscoelastic Model ◽  
Viscoelastic Behavior ◽  
Model Parameters ◽  
Viscoelastic Models ◽  
Nonlinear Viscoelastic ◽  
Compression Data ◽  
Computationally Intensive ◽  
Nonlinear Viscoelastic Model ◽  
Flexible Polyurethane

Flexible polyethylene foam is used in many engineering applications. It exhibits nonlinear and viscoelastic behavior which makes it difficult to model. To date, several models have been developed to characterize the complex behavior of foams. These attempts include the computationally intensive microstructural models to continuum models that capture the macroscale behavior of the foam materials. In this research, a nonlinear viscoelastic model, which is an extension to previously developed models, is proposed and its ability to capture foam response in uniaxial compression is investigated. It is hypothesized that total stress can be decomposed into the sum of a nonlinear elastic component, modeled by a higher-order polynomial, and a nonlinear hereditary type viscoelastic component. System identification procedures were developed to estimate the model parameters using uniaxial cyclic compression data from experiments conducted at six different rates. The estimated model parameters for individual tests were used to develop a model with parameters that are a function of strain rates. The parameter estimation technique was modified to also develop a comprehensive model which captures the uniaxial behavior of all six tests. The performance of this model was compared to that of other nonlinear viscoelastic models.

Identification of Nonlinear Viscoelastic Models of Flexible Polyurethane Foam From Uniaxial Compression Data

2012 ◽  
Author(s):  
Yousof Azizi ◽  
Patricia Davies ◽  
Anil K. Bajaj
Keyword(s):  
Uniaxial Compression ◽  
Viscoelastic Model ◽  
Viscoelastic Behavior ◽  
Model Parameters ◽  
Viscoelastic Models ◽  
Nonlinear Viscoelastic ◽  
Compression Data ◽  
Computationally Intensive ◽  
Nonlinear Viscoelastic Model ◽  
Flexible Polyurethane

Flexible polyethylene foam, which is used in many engineering applications, exhibits nonlinear and viscoelastic behavior. To date, several models have been proposed to characterize the complex behavior of foams from the computationally intensive microstructural models to continuum models that capture the macroscale behavior of the foam materials. A nonlinear viscoelastic model, which is an extension of previously developed models, is proposed and its ability to capture foam response in uniaxial compression is investigated. It is assumed in the model that total stress is decomposed into the sum of a nonlinear elastic component, which is modeled by a higher order polynomial, and a nonlinear hereditary type viscoelastic component. System identification procedures are developed to estimate the model parameters using uniaxial compression data from experiments conducted at different rates. The performance of this model is compared to that of other nonlinear viscoelastic models.

A Nonlinear Viscoelastic Model for the Relaxation Behavior of Tendon

2012 ◽  
Author(s):  
Frances M. Davis ◽  
Raffaella De Vita
Keyword(s):  
Stress Relaxation ◽  
Relaxation Function ◽  
Viscoelastic Model ◽  
Viscoelastic Behavior ◽  
Relaxation Behavior ◽  
Successful Model ◽  
Viscoelastic Models ◽  
Nonlinear Viscoelastic ◽  
Linear Viscoelastic ◽  
Nonlinear Viscoelastic Model

Tendons are viscoelastic materials which undergo stress relaxation when held at a constant strain. The most successful model used to describe the viscoelastic behavior of tendons is the quasi-linear viscoelastic (QLV) model [1]. In the QLV model, the relaxation function is assumed to be a separable function of time and strain. Recently, this assumption has been shown to be invalid for tendons [2] thus suggesting the need for new nonlinear viscoelastic models.

Linear and Quasi-Linear Viscoelastic Characterization of Ankle Ligaments

1999 ◽  
Vol 122 (1) ◽  
pp. 15-22 ◽  
Author(s):  
J. R. Funk ◽  
G. W. Hall ◽  
J. R. Crandall ◽  
W. D. Pilkey
Keyword(s):  
Lower Extremity ◽  
Ankle Ligaments ◽  
Viscoelastic Models ◽  
Nonlinear Viscoelastic ◽  
Human Ankle ◽  
Linear Viscoelastic ◽  
Failure Properties ◽  
Linear And Nonlinear ◽  
Model Failure

The objective of this study was to produce linear and nonlinear viscoelastic models of eight major ligaments in the human ankle/foot complex for use in computer models of the lower extremity. The ligaments included in this study were the anterior talofibular (ATaF), anterior tibiofibular (ATiF), anterior tibiotalar (ATT), calcaneofibular (CF), posterior talofibular (PTaF), posterior tibiofibular (PTiF), posterior tibiotalar (PTT), and tibiocalcaneal (TiC) ligaments. Step relaxation and ramp tests were performed. Back-extrapolation was used to correct for vibration effects and the error introduced by the finite rise time in step relaxation tests. Ligament behavior was found to be nonlinear viscoelastic, but could be adequately modeled up to 15 percent strain using Fung’s quasilinear viscoelastic (QLV) model. Failure properties and the effects of preconditioning were also examined. [S0148-0731(00)01001-3]

Application of nonlinear viscoelastic models to describe ligament behavior

2002 ◽  
Vol 1 (1) ◽  
pp. 45-57 ◽  
Author(s):  
P. P. Provenzano ◽  
R. S. Lakes ◽  
D. T. Corr ◽  
R. Vanderby
Keyword(s):  
Viscoelastic Models ◽  
Nonlinear Viscoelastic

Computer simulation of tire rolling resistance using finite element method: Effect of linear and nonlinear viscoelastic models

2018 ◽  
Vol 233 (11) ◽  
pp. 2746-2760 ◽  
Author(s):  
Mehdi Rafei ◽  
Mir Hamid Reza Ghoreishy ◽  
Ghasem Naderi
Keyword(s):  
Research Work ◽  
Viscoelastic Model ◽  
Rolling Resistance ◽  
Experimental Tests ◽  
Material Model ◽  
Resistance Force ◽  
Model Parameters ◽  
Inflation Pressure ◽  
Viscoelastic Models ◽  
Nonlinear Viscoelastic

This research work is devoted to the study of the effect of model parameters and material properties on tire rolling resistance. The main goal of this research is to investigate and clarify the effect of the adopted hyper-viscoelastic material model on tire rolling resistance simulation results. For this purpose, some new approaches were used and current shortcomings were introduced. Computer simulations were carried out using Abaqus standard command line. Linear and parallel rheological framework viscoelastic models were implemented and rolling resistance of a passenger car tire was determined. Different parametric simulations were carried out and the results were compared with rolling resistance data obtained from experimental tests. The results revealed that the calculated rolling resistance force depends on the implemented viscoelastic model. The linear viscoelastic model could not accurately predict the trend of rolling resistance with variation of tire inflation pressure and applied load. On the contrary, parallel rheological framework could cope with this trend. The parallel rheological framework model is more sensitive to inflation pressure. However, the sensitivity of both models to applied vertical load is nearly the same. Although cornering simulation is independent of the adopted viscoelastic model, the type of viscoelastic model could affect the footprint contact pressure contour.

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