scholarly journals Analytical solutions for the effective viscoelastic properties of composite materials with different shapes of inclusions

2021 ◽  
pp. 4-4
Author(s):  
Minh-Quan Thai ◽  
Sy-Tuan Nguyen ◽  
Thanh-Sang Nguyen ◽  
Phu-Son Mai
Keyword(s):  
Composite Materials ◽  
Viscoelastic Properties ◽  
Effective Properties ◽  
Poisson Ratio ◽  
Viscoelastic Behavior ◽  
Theory Of Elasticity ◽  
Homogenization Theory ◽  
Isotropic Case ◽  
Time Space ◽  
Different Shapes

This paper aims to model the effect of different shapes of inclusions on the homogenized viscoelastic properties of composite materials made of a viscoelastic matrix and inclusion particles. The viscoelastic behavior of the matrix phase is modeled by the Generalized Maxwell rheology. The effective properties are firstly derived by combining the homogenization theory of elasticity and the correspondence principle. Then, the effective rheological properties in time space are explicitly derived without using the complex inverse Laplace-Carson transformation (LC). Closed-form solutions for the effective bulk and shear rheological viscoelastic properties, the relaxation and creep moduli as well as the Poisson ratio are obtained for the isotropic case with random orientation distribution and different shapes of inclusions: spherical, oblate and elongate inclusions. The developed approach is validated against the exact solutions obtained by the classical inverse LC method. It is observed that the homogenized viscoelastic moduli are highly sensitive to different shapes of inclusions.

Limitations on the Use of Effective Properties for Multicomponent Materials

2008 ◽  
Vol 24 (1) ◽  
pp. 95-102
Author(s):  
R. Han ◽  
M. S. Ingber ◽  
S. C. Hsiao
Keyword(s):  
Composite Materials ◽  
Effective Properties ◽  
Poisson Ratio ◽  
Matrix Material ◽  
Effective Property ◽  
Shear Loading ◽  
Functionally Graded ◽  
Dispersed Phase ◽  
Shear Moduli ◽  
Young’S Moduli

ABSTRACTMulticomponent composite materials comprised of a dispersed phase suspended in a matrix material are important in a wide variety of scientific and engineering applications including electronic encapsulation, functionally graded materials, and fiber-reinforced structural components among others. Modelling of this class of composites is typically performed using an effective property approach. This approach presumes that the characteristic dimension of the dispersed phase elements is small in comparison to the characteristic length scale of the physical problem under consideration. However, it is not possible to predict a third effective elastic property based on two independent effective elastic properties as it is for homogeneous elastic isotropic materials. Therefore, a macroscale simulation based on an effective Young's modulus and Poisson ratio may yield poor results for a material subjected to shear loading since there is a potentially incorrect presumed effective shear modulus for the simulation. In the current research, boundary element simulations are performed for mesoscopic samples of composite materials to determine effective bulk moduli, shear moduli, Young's moduli, and Poisson ratios. From these analyses, limitations in the effective property approach can be examined.

scholarly journals 3D Plotting of Silica/Collagen Xerogel Granules in an Alginate Matrix for Tissue-Engineered Bone Implants

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 830
Author(s):  
Sina Rößler ◽  
Andreas Brückner ◽  
Iris Kruppke ◽  
Hans-Peter Wiesmann ◽  
Thomas Hanke ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Bone Regeneration ◽  
Material Properties ◽  
Viscoelastic Properties ◽  
Viscoelastic Behavior ◽  
Matrix Phase ◽  
Patient Specific ◽  
Active Player ◽  
Alginate Concentration ◽  
Alginate Matrix

Today, materials designed for bone regeneration are requested to be degradable and resorbable, bioactive, porous, and osteoconductive, as well as to be an active player in the bone-remodeling process. Multiphasic silica/collagen Xerogels were shown, earlier, to meet these requirements. The aim of the present study was to use these excellent material properties of silica/collagen Xerogels and to process them by additive manufacturing, in this case 3D plotting, to generate implants matching patient specific shapes of fractures or lesions. The concept is to have Xerogel granules as active major components embedded, to a large proportion, in a matrix that binds the granules in the scaffold. By using viscoelastic alginate as matrix, pastes of Xerogel granules were processed via 3D plotting. Moreover, alginate concentration was shown to be the key to a high content of irregularly shaped Xerogel granules embedded in a minimum of matrix phase. Both the alginate matrix and Xerogel granules were also shown to influence viscoelastic behavior of the paste, as well as the dimensionally stability of the scaffolds. In conclusion, 3D plotting of Xerogel granules was successfully established by using viscoelastic properties of alginate as matrix phase.

The Design of Composite Materials For Electro-Mechanical and Electro-Thermal Applications.

1983 ◽  
Vol 24 ◽  
Author(s):  
L. E. Cross
Keyword(s):  
Composite Materials ◽  
Figure Of Merit ◽  
Poisson Ratio ◽  
Dielectric Behavior ◽  
Thermal Mass ◽  
Secondary Effects ◽  
Pressure Sensing ◽  
Composite Systems ◽  
Reinforced Composite ◽  
Composite Microstructure

ABSTRACTIn composite materials for electro-mechanical applications, the importance of the mode in which the constituent phases are interconnected (connectivity) was stressed. For the tensor properties of mechanical, piezoelectric, and dielectric behavior, controlling the manner in which fields and fluxes thread through the composite can make orders of magnitude change in the coupled properties.Examples were drawn from piezoelectric ceramic:polymer composites for uniaxial and hydrostatic (hydrophone) pressure sensing where the 1:3 connected transversely reinforced composite can be shown to exhibit a figure of merit more than 103 that of the piezoceramic phase alone. In these systems, the importance of poisson ratio effects in the polymer phase were evident, and some new composite systems where the hydrostatic stiffness of the elastomer phases may be better exploited were considered.In electro-thermal applications such as in pyroelectric composites, the requirements of small-size and low-thermal mass put rigorous limits upon the scale of the composite microstructure. Techniques which achieve the appropriate scaling were described and preliminary data showed strong enhancement of the secondary effects in these composites were presented.

General Solutions of the Equations of Elasticity and Consolidation for a Porous Material

1956 ◽  
Vol 23 (1) ◽  
pp. 91-96
Author(s):  
M. A. Biot
Keyword(s):  
Stress Field ◽  
Porous Material ◽  
Elastic Material ◽  
Displacement Field ◽  
Theory Of Elasticity ◽  
Isotropic Case ◽  
General Solutions ◽  
General Properties ◽  
Stress Functions

Abstract Equations of elasticity and consolidation for a porous elastic material containing a fluid have been previously established (1, 5). General solutions of these equations for the isotropic case are developed, giving directly the displacement field or the stress field in analogy with the Boussinesq-Papkovitch solution and the stress functions of the theory of elasticity. General properties of the solutions also are examined and the viewpoint of eigenfunctions in consolidation problems is introduced.

Consistent Hashin-Shtrikman Bounds on the Effective Properties of Periodic Composite Materials

1999 ◽  
Vol 66 (4) ◽  
pp. 858-866
Author(s):  
P. Bisegna ◽  
R. Luciano
Keyword(s):  
Composite Materials ◽  
Saddle Point ◽  
Variational Principles ◽  
Effective Properties ◽  
The Other ◽  
Constitutive Behavior ◽  
Homogenization Problem ◽  
Numerical Examples ◽  
Periodic Composites ◽  
Periodic Composite

In this paper the four classical Hashin-Shtrikman variational principles, applied to the homogenization problem for periodic composites with a nonlinear hyperelastic constitutive behavior, are analyzed. It is proved that two of them are indeed minimum principles while the other two are saddle point principles. As a consequence, every approximation of the former ones provide bounds on the effective properties of composite bodies, while approximations of the latter ones may supply inconsistent bounds, as it is shown by two numerical examples. Nevertheless, the approximations of the saddle point principles are expected to provide better estimates than the approximations of the minimum principles.

The Mechanical and Viscoelastic Properties of the Healing Rabbit Patellar Tendon

2007 ◽  
Author(s):  
Steven D. Abramowitch ◽  
Matthew B. Fisher ◽  
Sinan Karaoglu ◽  
Savio L.-Y. Woo
Keyword(s):  
Patellar Tendon ◽  
Viscoelastic Properties ◽  
Cruciate Ligament ◽  
Donor Site ◽  
Viscoelastic Behavior ◽  
Surgery Complications ◽  
Contributing Factors ◽  
Anterior Cruciate ◽  
Anterior Knee ◽  
Bone Patellar Tendon

Central third bone-patellar tendon-bone (BPTB) autografts are commonly used for anterior cruciate ligament (ACL) reconstructions. Following surgery, complications arise at the donor site, including extension deficits and anterior knee pain [1]. These complications are partially caused by inadequate healing of the patellar tendon (PT) as well as adhesions in the anterior interval. Recent clinical data have suggested these are contributing factors in the early development of osteoarthrosis following ACL reconstruction [2]. Thus, it is necessary to understand the changes in mechanical and viscoelastic behavior in the healing PT.

ON AN EXACT DESCRIPTION OF THE SCHOTTKY GROUPS OF SYMMETRIES

2005 ◽  
Vol 9 (2) ◽  
pp. 137-148
Author(s):  
M. V. Dubatovskaya ◽  
S. V. Rogosin
Keyword(s):  
Composite Materials ◽  
Effective Properties ◽  
Schottky Groups ◽  
Multiply Connected ◽  
Schwarz Problem ◽  
Circular Domains ◽  
Exact Description

Exact description of the Schottky groups of symmetries is given for certain special configurations of multiply connected circular domains. It is used in the representation of the solution of the Schwarz problem which is applied at the study of effective properties of composite materials. Santrauka Darbe pateiktas Schottky simetrijos grupiu apibrežimas tam tikros specialios konfiguracijos daugiajungems skritulinems sritims. Jis yra panaudotas gaunant Švarco uždavinio, kuris pritaikomas nagrinejant efektyvias kompoziciju savybes, sprendinio išraiška.

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