scholarly journals Experimental methods for the characterization of the frequency-dependent viscoelastic properties of soft materials

2013 ◽  
Vol 133 (5) ◽  
pp. 3186-3197 ◽  
Author(s):  
Siavash Kazemirad ◽  
Hossein K. Heris ◽  
Luc Mongeau
Keyword(s):  
Viscoelastic Properties ◽  
Soft Materials ◽  
Experimental Methods ◽  
Frequency Dependent

scholarly journals Investigation of the Compressive Viscoelastic Properties of Brain Tissue Under Time and Frequency Dependent Loading Conditions

2021 ◽  
Author(s):  
Weiqi Li ◽  
Duncan E. T. Shepherd ◽  
Daniel M. Espino
Keyword(s):  
Finite Element ◽  
Brain Tissue ◽  
Time Domain ◽  
Viscoelastic Properties ◽  
Loss Modulus ◽  
Series Representation ◽  
Experimental Tests ◽  
Finite Element Models ◽  
Frequency Dependent

AbstractThe mechanical characterization of brain tissue has been generally analyzed in the frequency and time domain. It is crucial to understand the mechanics of the brain under realistic, dynamic conditions and convert it to enable mathematical modelling in a time domain. In this study, the compressive viscoelastic properties of brain tissue were investigated under time and frequency domains with the same physical conditions and the theory of viscoelasticity was applied to estimate the prediction of viscoelastic response in the time domain based on frequency-dependent mechanical moduli through Finite Element models. Storage and loss modulus were obtained from white and grey matter, of bovine brains, using dynamic mechanical analysis and time domain material functions were derived based on a Prony series representation. The material models were evaluated using brain testing data from stress relaxation and hysteresis in the time dependent analysis. The Finite Element models were able to represent the trend of viscoelastic characterization of brain tissue under both testing domains. The outcomes of this study contribute to a better understanding of brain tissue mechanical behaviour and demonstrate the feasibility of deriving time-domain viscoelastic parameters from frequency-dependent compressive data for biological tissue, as validated by comparing experimental tests with computational simulations.

Nondestructive characterization of soft materials and biofilms by measurement of guided elastic wave propagation using optical coherence elastography

Soft Matter ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 575-586 ◽  
Author(s):  
Hong-Cin Liou ◽  
Fabrizio Sabba ◽  
Aaron I. Packman ◽  
George Wells ◽  
Oluwaseyi Balogun
Keyword(s):  
Wave Propagation ◽  
Elastic Wave ◽  
Mixed Culture ◽  
Viscoelastic Properties ◽  
Guided Waves ◽  
Soft Materials ◽  
Bacterial Biofilms ◽  
Optical Coherence ◽  
Nondestructive Characterization

Elastic guided waves were generated in mixed-culture bacterial biofilms for characterizing its viscoelastic properties.

Electrical frequency dependent characterization of DNA hybridization

2003 ◽  
Vol 19 (2) ◽  
pp. 95-102 ◽  
Author(s):  
Marin Gheorghe ◽  
Anthony Guiseppi-Elie
Keyword(s):  
Dna Hybridization ◽  
Frequency Dependent

A novel wave propagation method for measuring viscoelastic properties of pre-strained materials

2021 ◽  
pp. 1-19
Author(s):  
Pierre Lemerle
Keyword(s):  
Wave Propagation ◽  
Viscoelastic Properties ◽  
Time History ◽  
Main Concept ◽  
Frequency Dependent ◽  
Damping Characteristics ◽  
History Of ◽  
Propagation Methods ◽  
The Time Domain ◽  
Waveform Pattern

Abstract Viscoelastic materials are widely used for vibroacoustic solutions due to their ability to mitigate vibration and sound. Wave propagation methods are based on the measurement of the waveform pattern of a transitory pulse in one-dimensional structures. The time evolution of the pattern can be used to deduce the material elasticity and damping characteristics. The most popular propagation methods, namely Hopkinson bar methods, assume no dispersion, i.e. the complex elasticity modulus is not frequency-dependent. This is not significant for resilient materials such as elastomers. More recent approaches have been developed to measure frequency-dependent properties from a pulse propagating in a slender bar. We showed in previous works how to adapt these techniques for shorter samples of materials, representing a real advance, as extrusion is a cumbersome process for many materials. The main concept was to reconstruct the time history of the wave propagating in a composite structure composed of a long incident bar made of a known material and extended by a shorter sample bar. Then the viscoelastic properties of the sample material were determined in the frequency domain within an inverse method held in the time domain. In industry, most isolation solutions using mounts or bushings must support structural weights. This is why it is particularly interesting to know the viscoelastic properties of the material in stressed state. Here, we show how to overcome this challenging issue. The theoretical framework of the computational approach is detailed and the method is experimentally verified.

Electrothermal Characterization of Doped-Si Heated Microcantilevers Under Periodic Heating Operation

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Sina Hamian ◽  
Andrew M. Gauffreau ◽  
Timothy Walsh ◽  
Jungchul Lee ◽  
Keunhan Park
Keyword(s):  
Microelectromechanical Systems ◽  
Transfer Functions ◽  
Design Parameters ◽  
Periodic Heating ◽  
Element Analysis ◽  
Full Spectrum ◽  
Frequency Dependent ◽  
Thermal Transfer ◽  
Fea Model

This paper reports the frequency-dependent electrothermal behaviors of a freestanding doped-silicon heated microcantilever probe operating under periodic (ac) Joule heating. We conducted a frequency-domain finite-element analysis (FEA) and compared the steady periodic solution with 3ω experiment results. The computed thermal transfer function of the cantilever accurately predicts the ac electrothermal behaviors over a full spectrum of operational frequencies, which could not be accomplished with the 1D approximation. In addition, the thermal transfer functions of the cantilever in vacuum and in air were compared, through which the frequency-dependent heat transfer coefficient of the air was quantified. With the developed FEA model, design parameters of the cantilever (i.e., the size and the constriction width of the cantilever heater) and their effects on the ac electrothermal behaviors were carefully investigated. Although this work focused on doped-Si heated microcantilever probes, the developed FEA model can be applied for the ac electrothermal analysis of general microelectromechanical systems.

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