Visco-hyperelastic constitutive modeling of strain rate sensitive soft materials

Upadhyay, Kshitiz; Subhash, Ghatu; Spearot, Douglas E.

doi:10.1016/j.jmps.2019.103777

Cited by 70 publications

(56 citation statements)

References 75 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The entropy production is assumed to be entirely due to viscous dissipation, and the external thermodynamic state variable is given by C˙ (recall (2.10) in relation to this) so that the nonlinear strain rate dependency of materials is captured. These models have been studied extensively modelling soft tissues such as brain, tongue tissue, tendons and skeletal muscles (see [95] and references therein). In these models, similar to the situation in (3.14), an additive relationship between the elastic (corresponding to the hyperelastic strain energy density) and viscoelastic stress (corresponding to a viscous dissipation potential) is introduced.…”

Section: Applicationsmentioning

confidence: 99%

“…In these models, similar to the situation in (3.14), an additive relationship between the elastic (corresponding to the hyperelastic strain energy density) and viscoelastic stress (corresponding to a viscous dissipation potential) is introduced. In [95], experimental data of human brain tissue grey matter are compared with numerically fitted response in uniaxial and simple shear deformations showing that such models capture all features of stress–strain data.…”

Section: Applicationsmentioning

confidence: 99%

See 1 more Smart Citation

Nonlinear viscoelasticity of strain rate type: an overview

Şengül

2021

Proc. R. Soc. A.

View full text Add to dashboard Cite

There are some materials in nature that experience deformations that are not elastic. Viscoelastic materials are some of them. We come across many such materials in our daily lives through a number of interesting applications in engineering, material science and medicine. This article concerns itself with modelling of the nonlinear response of a class of viscoelastic solids. In particular, nonlinear viscoelasticity of strain rate type, which can be described by a constitutive relation for the stress function depending not only on the strain but also on the strain rate, is considered. This particular case is not only favourable from a mathematical analysis point of view but also due to experimental observations, knowledge of the strain rate sensitivity of viscoelastic properties is crucial for accurate predictions of the mechanical behaviour of solids in different areas of applications. First, a brief introduction of some basic terminology and preliminaries, including kinematics, material frame-indifference and thermodynamics, is given. Then, considering the governing equations with constitutive relationships between the stress and the strain for the modelling of nonlinear viscoelasticity of strain rate type, the most general model of interest is obtained. Then, the long-term behaviour of solutions is discussed. Finally, some applications of the model are presented.

show abstract

Section: Applicationsmentioning

confidence: 99%

Section: Applicationsmentioning

confidence: 99%

Nonlinear viscoelasticity of strain rate type: an overview

Şengül

2021

Proc. R. Soc. A.

View full text Add to dashboard Cite

show abstract

“…Their model predicts monotonic loading, material relaxation and viscous dissipation during loading and unloading cycle very well but it overestimates stiffness during unloading. Realising the power of a dissipation potential, [35] formulated a visco-hyperelastic constitutive model of short-term memory response for soft materials to capture both linear and nonlinear large deformation behaviour over a wide range of strain rates. The model displays great accuracy and avoids possible thermodynamic instabilities normally found in quasi-static hyperelastic models that corrupt dynamic stresses.…”

Section: Introductionmentioning

confidence: 99%

The Application of Standard Nonlinear Solid Material Models in Modelling the Tensile Behaviour of the Supraspinatus Tendon

Ngwangwa¹,

Pandelani²,

Ṋemavhola³

2021

Preprint

View full text Add to dashboard Cite

Tendons transmit forces from muscles to bones through joints. Typically, tendons and muscles work together to innovate a particular type of motion. Therefore, in order for the tendons to find attachment to the bones, they are naturally adapted as much thinner strands than the muscles that they serve. Thus, they are often subjected to much higher stresses than the muscles that they actually serve in any given action. As a result, tendons are susceptible to injuries that may lead to a permanent dysfunction in joint mobility due to the fact that the scar tissue that forms after healing does not often have the same mechanical properties of the original tissue. It is, therefore, very important to understand the mechanical response of tendons. This paper examines the performances of two viscoelastic standard nonlinear models in modelling the elastic and plastic behaviour of the tendon in the light of a well-known hyperelastic Yeoh model. The use of the Yeoh model is more for validating the performances of the viscoelastic models within the elastic region rather than for comparison purposes. Yeoh model’s selection was based on its superior performance in modelling the elastic phase of soft tissue as reported in previous studies combined with its simplicity. The results show that the two standard nonlinear solid models perform extremely well both in fitting accuracies and in correlating stress results. The most promising result is the fact that the two standard nonlinear models can model tendon behaviour in the nonlinear plastic region. It is also noted that the two standard nonlinear models are physically insightful since their optimisation parameters can be easily interpreted in terms of tendon elasticity and viscoelastic parameters.

show abstract

Section: Introductionmentioning

confidence: 99%

“…This is a significant deficiency because consideration of experimental data from all the three primary deformation modes of compression, tension and shear at constant strain rates is suggested for the calibration of the hyperelastic and visco-hyperelastic constitutive models commonly used for hydrogels. [25][26][27] The major challenges in testing the shear properties of agarose hydrogels include specimen preparation, gripping of the soft and slippery surfaces that do not result in specimen damage and measurement of local strain within the test area. In some cases, adhesives, such as polymeric glue, can be used to hold the gel in place, but slipping could still occur and alter property data.…”

Section: Introductionmentioning

confidence: 99%

An improved direct shear characterisation technique for soft gelatinous and elastomeric materials

Millar

Mennu

Upadhyay

et al. 2021

Strain

Self Cite

View full text Add to dashboard Cite

Soft materials such as hydrogels and elastomers exhibit very low stiffness and strength as well as large deformations, which makes their mechanical characterisation extremely difficult through conventional methods. This paper presents a novel experimental technique for the mechanical shear property characterisation of these materials. Agarose hydrogels were chosen as a model material for this study. The new in‐plane shear test method incorporates 3‐D‐printed acrylonitrile butadiene styrene (ABS) grips for specimen mounting and digital image correlation (DIC) for full‐field strain measurement on both sides of the specimen gauge section. These grips utilise barb‐like pegs to secure the specimen while load is applied. In order to evaluate the methodology, four concentrations of agarose hydrogel (4.0%, 2.5%, 1.5%, and 0.5% wt./solvent volume) were tested. Results for the agarose hydrogel demonstrated excellent repeatability. The obtained shear moduli show a monotonic increase with gel concentration. Furthermore, the range of shear moduli applicable to the novel testing method was determined.

show abstract

Visco-hyperelastic constitutive modeling of strain rate sensitive soft materials

Cited by 70 publications

References 75 publications

Nonlinear viscoelasticity of strain rate type: an overview

Nonlinear viscoelasticity of strain rate type: an overview

The Application of Standard Nonlinear Solid Material Models in Modelling the Tensile Behaviour of the Supraspinatus Tendon

An improved direct shear characterisation technique for soft gelatinous and elastomeric materials

Contact Info

Product

Resources

About