scholarly journals Multiscale modeling and simulation of magneto-active elastomers based on experimental data

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Karl A. Kalina ◽  
Alexander Raβloff ◽  
Maximilian Wollner ◽  
Philipp Metsch ◽  
Jörg Brummund ◽  
...  
Keyword(s):  
Experimental Data ◽  
Modeling And Simulation ◽  
Multiscale Modeling ◽  
Constitutive Models ◽  
Elastic Model ◽  
The Finite Element Method ◽  
Effective Response ◽  
General Continuum ◽  
The Individual

AbstractIn this contribution, we present a framework for the multiscale modeling and simulation of magneto-active elastomers (MAEs). It enables us to consider these materials on the microscopic scale, where the heterogeneous microstructure consisting of magnetizable particles and elastomer matrix is explicitly resolved, as well as the macroscopic scale, where the MAE is considered to be a homogeneous magneto-active body. On both scales, a general continuum formulation of the coupled magneto-mechanical boundary value problem is applied and the finite element method is used to solve the governing equations. Starting with an experimental characterization of the individual constituents, i.e. particles and matrix, microscopic constitutive models for both are formulated and adjusted to the experimental data separately. With that, properties of MAEs resulting from the microscopic constitutive behavior can be captured within the presented modeling approach. Secondly, to discuss general macroscopic properties of magnetically soft and hard MAEs, a computational homogenization scheme is used to calculate the composites’ effective behavior for different geometrical arrangements of the particles on the microscale. Finally, the calculated effective response of a magnetically soft composite system is used to identify the parameters of a macroscopic magneto-elastic model. Using the calibrated model, the behavior of macroscopic MAEs is simulated for different sample geometries.

scholarly journals 24 Multiscale modeling and simulation of magneto-active elastomers based on experimental data

2021 ◽  
pp. 565-596
Author(s):  
Karl A. Kalina ◽  
Alexander Raβloff ◽  
Maximilian Wollner ◽  
Philipp Metsch ◽  
Jörg Brummund ◽  
...  
Keyword(s):  
Experimental Data ◽  
Modeling And Simulation ◽  
Multiscale Modeling

Interpretation of Experimental Data is Substantial for Constitutive Characterization of Arterial Tissue

2021 ◽  
Author(s):  
Ondrej Lisický ◽  
Anna Hrubanová ◽  
Jiri Bursa
Keyword(s):  
Experimental Data ◽  
Soft Tissues ◽  
Constitutive Models ◽  
Uniaxial Stress ◽  
Mechanical Tests ◽  
Data Sets ◽  
Stress Strain ◽  
Rigorous Approach ◽  
Carotid Wall

Abstract The paper aims at evaluation of mechanical tests of soft tissues and creation of their representative stress-strain responses and respective constitutive models. Interpretation of sets of experimental results depends highly on the approach to the data analysis. Their common representation through mean and standard deviation may be misleading and give non-realistic results. In the paper, raw data of 7 studies consisting of 11 experimental data sets (concerning carotid wall and atheroma tissues) are re-analysed to show the importance of their rigorous analysis. The sets of individual uniaxial stress-strain curves are evaluated using three different protocols: stress-based, stretch-based and constant-based, and the population-representative response is created by their mean or median values. Except for nearly linear responses, there are substantial differences between the resulting curves, being mostly the highest for constant-based evaluation. But also the stretch-based evaluation may change the character of the response significantly. Finally, medians of the stress-based responses are recommended as the most rigorous approach for arterial and other soft tissues with significant strain stiffening.

Characterization of Hyperelastic Dielectric Elastomer Based on Biaxial Tensile Bench

2010 ◽  
Vol 97-101 ◽  
pp. 884-888
Author(s):  
Hua An Luo ◽  
Hua Ming Wang ◽  
Jian Ying Zhu ◽  
You Peng You
Keyword(s):  
Experimental Data ◽  
Biaxial Loading ◽  
Constitutive Models ◽  
Dielectric Elastomer ◽  
Least Square ◽  
Model Parameters ◽  
Viscous Effect ◽  
Minimization Method ◽  
Biaxial Tensile

Usually model parameters from uniaxial experiments are not suitable for dielectric elastomer under biaxial loading condition. To characterize the mechanical behavior of dielectric elastomer, a biaxial tensile bench is established, on which uniaxial tests can be performed too. On the basis of the analysis of viscous effect of elastomer, experimental condition for data acquirement is determined. Then equi-biaxial and uniaxial experimental data are obtained to fit three constitutive models, i.e. Mooney-Rivlin, Yeoh and Ogden model. Also, least square minimization method is used to obtained model parameters, which are applicable to both uniaxial and equi-biaxial experimental data.

Study of potential curves by UHF type methods. CH4 molecule and its dissociation products

1986 ◽  
Vol 51 (4) ◽  
pp. 731-737
Author(s):  
Viliam Klimo ◽  
Jozef Tiňo
Keyword(s):  
Experimental Data ◽  
Quantum Chemistry ◽  
High Energy ◽  
Basis Set ◽  
Electronic Correlation ◽  
Exact Methods ◽  
Energy Parameters ◽  
Bond Functions ◽  
The Individual ◽  
Potential Curves

Geometry and energy parameters of the individual dissociation intermediate steps of CH4 molecule, parameters of the barrier to linearity and singlet-triplet separation of the CH2 molecule have been calculated by means of the UMP method in the minimum basis set augmented with the bond functions. The results agree well with experimental data except for the geometry of CH2(1A1) and relatively high energy values of CH(2II) and CH2(1A1) where the existence of two UHF solutions indicates a necessity of description of the electronic correlation by more exact methods of quantum chemistry.

Separation and Characterization of Standard Propoxyphene Diastereomers and Their Determination in Pharmaceutical and Illicit Preparations

1981 ◽  
Vol 64 (4) ◽  
pp. 875-883
Author(s):  
Shiv K Soni ◽  
Daniel Van Gelder
Keyword(s):  
High Pressure ◽  
Optical Isomers ◽  
Gold Chloride ◽  
Melting Points ◽  
Eutectic Melting ◽  
Racemic Mixtures ◽  
The Individual ◽  
Isomeric Mixtures ◽  
Asymmetric Carbon

Abstract Due to the existence of 2 asymmetric carbon atoms in: the propoxyphene molecule, there are 4 diastereomers: alpha dextro, alpha levo, beta dextro, and beta levo. Only α-d-propoxyphene is included under the federal Controlled Substances Act. Baseline separations of propoxyphene from various incipients (aspirin, caffeine, phenacetin, and acetaminophen) present in pharmaceutical and illicit preparations, and between the alpha and beta diastereomers, were achieved by high pressure liquid chromatography. The column eluant was collected and propoxyphene was extracted. The optical isomers were differentiated and characterized by melting points and by chemical microcrystalline tests. Using hot stage thermomicroscopy, the eutectic melting points of binary isomeric mixtures of propoxyphene bases and salts were found to be depressed about 10° and 15-30°C, respectively, below the individual isomer melting points. The characteristic microcrystals formed with the alpha racemic mixtures by using a glycerin-aqueous gold chloride reagent were not produced by the beta racemic mixtures.

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