Micromechanics-based characterization of elastic properties of shape memory polymer nanocomposites containing SiO2 nanoparticles

2018 ◽  
Vol 29 (11) ◽  
pp. 2392-2405 ◽  
Author(s):  
Mohammad Kazem Hassanzadeh-Aghdam ◽  
Mohammad Javad Mahmoodi
Keyword(s):  
Elastic Modulus ◽  
Shape Memory ◽  
Polymer Nanocomposites ◽  
Elastic Properties ◽  
Poisson’S Ratio ◽  
Shape Memory Polymer ◽  
Polymer Nanocomposite ◽  
Poisson's Ratio ◽  
Interphase Region ◽  
Nanoparticle Diameter

In this article, a unit cell micromechanics model is developed to predict the elastic properties of shape memory polymer nanocomposites containing silica (SiO2) nanoparticles. The model incorporates an interphase zone corresponding to a perturbed region of shape memory polymer matrix around SiO2 nanoparticles. It is found that the elastic properties of shape memory polymer nanocomposites are significantly sensitive to the temperature in the presence of interphase region. As the temperature increases, the shape memory polymer nanocomposite elastic modulus decreases, while the normalized elastic modulus nonlinearly rises. The results reveal that Poisson’s ratio decreases nonlinearly with the increase of temperature. The shape memory polymer nanocomposite mechanical properties are significantly influenced by the nanoparticle diameter in the presence of interphase region. Substantial improvement in normalized elastic modulus is observed with reducing the nanoparticle diameter. Also, a nonlinear decrease in Poisson’s ratio is found as the nanoparticle diameter decreases. Furthermore, the role of nanoparticle diameter becomes more prominent due to enhancement of temperature. The results indicate that with increasing SiO2 nanoparticles’ volume fraction, the elastic modulus of shape memory polymer nanocomposite nonlinearly rises, while Poisson’s ratio decreases. Finally, it is shown that the increase of interphase thickness leads to the enhancement of normalized elastic modulus of shape memory polymer nanocomposite.

scholarly journals Effects of added SiO2 nanoparticles on the thermal expansion behavior of shape memory polymer nanocomposites

2018 ◽  
Vol 30 (1) ◽  
pp. 32-44 ◽  
Author(s):  
Mohammad Javad Mahmoodi ◽  
Mohammad Kazem Hassanzadeh-Aghdam ◽  
Reza Ansari
Keyword(s):  
Thermal Expansion ◽  
Shape Memory ◽  
Polymer Nanocomposites ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Shape Memory Polymer ◽  
Polymer Nanocomposite ◽  
Thermal Expansion Behavior ◽  
Interphase Region ◽  
Expansion Behavior

In this study, a unit cell–based micromechanical approach is proposed to analyze the coefficient of thermal expansion of shape memory polymer nanocomposites containing SiO2 nanoparticles. The interphase region created due to the interaction between the SiO2 nanoparticles and shape memory polymer is modeled as the third phase in the nanocomposite representative volume element. The influences of the temperature, volume fraction, and diameter of the SiO2 nanoparticles on the thermal expansion behavior of shape memory polymer nanocomposite are explored. It is observed that the coefficient of thermal expansion of shape memory polymer nanocomposite decreases with the increase in the volume fraction up to 12%. Also, the results reveal that with the increase in temperature, the shape memory polymer nanocomposite coefficient of thermal expansion linearly increases. The role of interphase region on the thermal expansion response of the shape memory polymer nanocomposite is found to be very important. In the presence of interphase, the reduction in nanoparticle diameter leads to lower coefficient of thermal expansion for shape memory polymer nanocomposite, while the variation of nanoparticles diameter does not affect the coefficient of thermal expansion in the absence of interphase. Based on the simulation results, the shape memory polymer nanocomposite coefficient of thermal expansion decreases as the interphase thickness increases. In addition, the contribution of interphase coefficient of thermal expansion to the shape memory polymer nanocomposite coefficient of thermal expansion is more significant than that of interphase elastic modulus.

Interphase influences on the mechanical behavior of carbon nanotube–shape memory polymer nanocomposites: A micromechanical approach

2018 ◽  
Vol 30 (3) ◽  
pp. 463-478 ◽  
Author(s):  
MK Hassanzadeh-Aghdam ◽  
MJ Mahmoodi ◽  
R Ansari ◽  
A Darvizeh
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Shape Memory ◽  
Polymer Nanocomposites ◽  
Elastic Moduli ◽  
Volume Fraction ◽  
Shape Memory Polymer ◽  
Micromechanical Model ◽  
Elastic Behavior ◽  
Interphase Region

The effects of interphase characteristics on the elastic behavior of randomly dispersed carbon nanotube–reinforced shape memory polymer nanocomposites are investigated using a three-dimensional unit cell–based micromechanical method. The interphase region is formed due to non-bonded van der Waals interaction between a carbon nanotube and a shape memory polymer. The influences of temperature, diameter, volume fraction, and arrangement type of carbon nanotubes within the matrix as well as two interphase factors, including adhesion exponent and thickness on the carbon nanotube/shape memory polymer nanocomposite’s longitudinal and transverse elastic moduli, are explored extensively. Moreover, the results are presented for the shape memory polymer nanocomposites containing randomly oriented carbon nanotubes. The obtained results clearly demonstrate that the interphase region plays a crucial role in the modeling of the carbon nanotube/shape memory polymer nanocomposite’s elastic moduli. It is observed that the nanocomposite’s elastic moduli remarkably increase with increasing interphase thickness or decreasing adhesion exponent. It is found that when the interphase is considered in the micromechanical simulation, the shape memory polymer nanocomposite’s elastic moduli non-linearly increase as the carbon nanotube diameter decreases. The predictions of the present micromechanical model are compared with those of other analytical methods and available experiments.

A Comparative Study on Elastic Behavior of Trefoil Patterned Perforated Plate

2010 ◽  
Author(s):  
Min-Ki Cho ◽  
Chang-Hoon Ha ◽  
Moo-Yong Kim ◽  
Sang-Cheol Lee ◽  
Jea-Mean Koo ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Elastic Modulus ◽  
Elastic Properties ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Element Analysis ◽  
Bending Tests ◽  
Support Plate ◽  
The Finite Element Analysis

A tube support plate is one of the significant parts of a steam generator, which confines the rotational and translational motion of tubes caused by the hydraulic and seismic load. It also provides a flow path along the tubes. There are various types of tube support plates according to the component designer’s preference. In this investigation, ten types of trefoil Broached Tube Support Plate (BTSP) specimens made from ASME stainless steel were analyzed and tested to determine the appropriate shape of trefoil BTSP in the view of the elastic properties including elastic modulus and Poisson’s ratio. The types of trefoil BTSP specimens were designated as SI through S5 and L1 through L5 for S and L types, respectively. These specimens are categorized by the shape and dimension of broached hole. Ten specimens were investigated through finite element analysis, and compression and bending tests. The dimensions of the test specimens were decided through a previous research study done to examine appropriate shape for the compression and bending tests. The equivalent elastic properties of BTSP were obtained by the finite element analysis as per different loading orientation as well as the various specimen types. Autodesk® Inventor™ software was used to make the analytical model and ABAQUS® software was used for the analysis and post-processing. The equivalent elastic properties of BTSP specimens were also acquired by the compression and bending tests. From the results of the finite element analysis, and the compression and bending tests, the appropriate shapes of trefoil BTSP with regard to the equivalent elastic modulus, and Poisson’s ratio are suggested as L4, S3, and S4.

scholarly journals Shape memory polymer-based hybrid honeycomb structures with zero Poisson’s ratio and variable stiffness

2017 ◽  
Vol 179 ◽  
pp. 437-443 ◽  
Author(s):  
Jian Huang ◽  
Qiuhua Zhang ◽  
Fabrizio Scarpa ◽  
Yanju Liu ◽  
Jinsong Leng
Keyword(s):  
Shape Memory ◽  
Poisson’S Ratio ◽  
Shape Memory Polymer ◽  
Variable Stiffness ◽  
Poisson's Ratio ◽  
Honeycomb Structures

Using the elastic modulus defect for diagnostics of plastic deformation of metal

2020 ◽  
pp. 34-35
Author(s):  
M.M. Matlin ◽  
V.A. Kazankin ◽  
E.N. Kazankina ◽  
A.I. Mozgunova ◽  
A.I. Sotnikova
Keyword(s):  
Plastic Deformation ◽  
Elastic Modulus ◽  
Elastic Properties ◽  
Modulus Of Elasticity ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Modulus Defect ◽  
Non Destructive

A non-destructive method for assessing the plastic deformation of a metal after processing a product is proposed, based on a change in the elastic properties of the material. Keywords metal, elastic properties, modulus of elasticity, Poisson's ratio, plastic deformation, non-destructive method, tension. [email protected]

The Model for Calculating Elastic Modulus and Poisson's Ratio of Coal Body

2013 ◽  
Vol 6 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Ai Chi ◽  
Li Yuwei
Keyword(s):  
Elastic Modulus ◽  
Poisson’S Ratio ◽  
Fractured Rock ◽  
Rock Block ◽  
Poisson's Ratio ◽  
Linear Elastic ◽  
Study Results ◽  
The Face ◽  
Block Face ◽  
Coal Rock

Coal body is a type of fractured rock mass in which lots of cleat fractures developed. Its mechanical properties vary with the parametric variation of coal rock block, face cleat and butt cleat. Based on the linear elastic theory and displacement equivalent principle and simplifying the face cleat and butt cleat as multi-bank penetrating and intermittent cracks, the model was established to calculate the elastic modulus and Poisson's ratio of coal body combined with cleat. By analyzing the model, it also obtained the influence of the parameter variation of coal rock block, face cleat and butt cleat on the elastic modulus and Poisson's ratio of the coal body. Study results showed that the connectivity rate of butt cleat and the distance between face cleats had a weak influence on elastic modulus of coal body. When the inclination of face cleat was 90°, the elastic modulus of coal body reached the maximal value and it equaled to the elastic modulus of coal rock block. When the inclination of face cleat was 0°, the elastic modulus of coal body was exclusively dependent on the elastic modulus of coal rock block, the normal stiffness of face cleat and the distance between them. When the distance between butt cleats or the connectivity rate of butt cleat was fixed, the Poisson's ratio of the coal body initially increased and then decreased with increasing of the face cleat inclination.

Research on dynamic characteristics of gear system considering the influence of temperature on material performance

2021 ◽  
pp. 107754632110026
Author(s):  
Zhou Sun ◽  
Siyu Chen ◽  
Xuan Tao ◽  
Zehua Hu
Keyword(s):  
Elastic Modulus ◽  
Dynamic Characteristics ◽  
Poisson’S Ratio ◽  
Gear System ◽  
Poisson's Ratio ◽  
Effect Of Temperature ◽  
Time Varying ◽  
Influence Of Temperature ◽  
Meshing Stiffness ◽  
Influence Of Temperature On

Under high-speed and heavy-load conditions, the influence of temperature on the gear system is extremely important. Basically, the current work on the effect of temperature mostly considers the flash temperature or the overall temperature field to cause expansion at the meshing point and then affects nonlinear factors such as time-varying meshing stiffness, which lead to the deterioration of the dynamic transmission. This work considers the effect of temperature on the material’s elastic modulus and Poisson’s ratio and relates the temperature to the time-varying meshing stiffness. The effects of temperature on the elastic modulus and Poisson’s ratio are expressed as functions and brought into the improved energy method stiffness calculation formula. Then, the dynamic characteristics of the gear system are analyzed. With the bifurcation diagram, phase, Poincaré, and fast Fourier transform plots of the gear system, the influence of temperature on the nonlinear dynamics of the gear system is discussed. The numerical analysis results show that as the temperature increases, the dynamic response of the system in the middle-speed region gradually changes from periodic motion to chaos.

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