scholarly journals Electromechanical response of multilayered piezoelectric BaTiO3/PZT-7A composites with wavy architecture

2021 ◽  
pp. 1045389X2098388
Author(s):  
Wenqiong Tu ◽  
Qiang Chen
Keyword(s):  
Finite Element ◽  
Finite Volume ◽  
Volume Fraction ◽  
Piezoelectric Materials ◽  
Electric Displacement ◽  
Element Model ◽  
Numerical Convergence ◽  
Analysis And Design ◽  
Poling Direction ◽  
Microstructural Effects

Electromechanical laminated composites with piezoelectric phases are increasingly being explored as multifunctional materials providing energy conversion between electric and mechanical energies. The current work explores thus-far undocumented combined microstructural effects of amplitude-to-wavelength ratio, volume fraction, poling direction of piezoelectric phases on both the homogenized properties and localized stress/electric field distributions in multilayered configurations under fully coupled electro-mechanical loading. In particular, the Multiphysics Finite-Volume Direct Averaging Micromechanics (FVDAM) and its counterpart, an in-house micromechanical multiphysics finite-element model, are utilized to investigate the homogenized and localized responses of wavy multilayered piezoelectric BaTiO3/PZT-7A architectures. These two methods generate highly agreeable results. Moreover, we critically examine the convergence of the finite-volume and finite element-based approaches via the Average Stress Theorem and Average Electric Displacement Theorem. The comparison shows the finite volume-based approach possesses a better numerical convergence. This study illustrates the FVDAM’s ability toward the analysis and design of engineered multilayered piezoelectric materials with wavy architecture.

scholarly journals Microstructural Modeling and Strengthening Mechanism of TiB/Ti-6Al-4V Discontinuously-Reinforced Titanium Matrix Composite

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 827 ◽  
Author(s):  
Shuai Zhao ◽  
Yangjian Xu ◽  
Changliang Pan ◽  
Lihua Liang ◽  
Xiaogui Wang
Keyword(s):  
Finite Element ◽  
Matrix Composite ◽  
Distribution Density ◽  
Volume Fraction ◽  
Element Model ◽  
Titanium Matrix ◽  
Titanium Matrix Composite ◽  
Finite Element Software ◽  
Multiple User ◽  
Thiessen Polygon

A novel modeling method was proposed to provide an improved representation of the actual microstructure of TiB/Ti-6Al-4V discontinuously-reinforced titanium matrix composite (DRTMC). Based on the Thiessen polygon structure, the representative volume element (RVE) containing the complex microstructures of the DRTMC was first generated. Thereafter, by using multiple user-defined subroutines in the commercial finite element software ABAQUS, the application of asymmetric mesh periodic boundary conditions on the RVE was realized, and the equivalent elastic modulus of the DRTMC was determined according to the homogenization method. Through error analyses on the experimental and calculated results regarding the equivalent elastic parameters of the DRTMC, the rationality of generating the DRTMC finite element model by using the present method was validated. Finally, simulations based on four types of network-like models revealed that the present simplifications to the particle shape of the reinforcement phase had less of an influence on the overall composite strength. Moreover, the present study demonstrates that the DRTMC enhancement is mainly attributed to the matrix strengthening, rather than the load-transferring mechanism. The strengthening influences of the distribution forms of the reinforcement phases, including their distribution density and orientation, were studied further. It was found that both the higher distribution density and limited distribution orientation of the particles would increase the probability of overlapping and merging between particles, and; therefore, higher strength could be yielded when the volume fraction of the reinforcement phase reached a certain threshold. Owing to the versatility of the developed methods and programs, this work can provide a useful reference for the characterization of the mechanical properties of other composites types.

The Effects of Layer-by-Layer Thickness and Fiber Volume Fraction Variation on the Mechanical Performance of a Pressure Vessel

2018 ◽  
Author(s):  
Emre Özaslan ◽  
Ali Yetgin ◽  
Volkan Coşkun ◽  
Bülent Acar ◽  
Tarık Olğar
Keyword(s):  
Finite Element ◽  
Layer Thickness ◽  
Pressure Vessel ◽  
Fiber Volume Fraction ◽  
Mechanical Performance ◽  
Volume Fraction ◽  
Element Model ◽  
Layer By Layer ◽  
Fiber Volume ◽  
Filament Wound

Due to high stiffness/weight ratio, composite materials are widely used in aerospace applications such as motor case of rockets which can be regarded as a pressure vessel. The most commonly used method to manufacture the pressure vessels is the wet filament winding. However, the mechanical performance of a filament wound pressure vessel directly depends on the manufacturing process, manufacturing site environmental condition and material properties of matrix and fiber. The designed ideal pressure vessel may not be manufactured because of the mentioned issues. Therefore, manufacturing of filament wound composite structures are based on manufacturing experience and experiment. In this study, the effect of layer-by-layer thickness and fiber volume fraction variation due to manufacturing process on the mechanical performance was investigated for filament wound pressure vessel with unequal dome openings. First, the finite element model was created for designed thickness dimensions and constant material properties for all layers. Then, the model was updated. The updated finite element model considered the layer-by-layer thickness and fiber volume fraction variation. Effects of the thickness and fiber volume fraction on the stress distribution along the motor axial direction were shown. Also hydrostatic pressurization test was performed to verify finite element analysis in terms of fiber direction strain through the motor case outer surface. Important aspects of analyzing a filament wound pressure vessel were addressed for designers.

Simulation of Crank-Rocker Mechanism on Finite Element by ANSYS

2012 ◽  
Vol 605-607 ◽  
pp. 626-629
Author(s):  
Xin Yu Zhang
Keyword(s):  
Finite Element ◽  
Theoretical Analysis ◽  
Finite Element Model ◽  
Dynamic Characteristics ◽  
Element Model ◽  
Analysis And Design

This paper has analyzed the movement of the crank-rocker mechanism by a simple finite element model, to study the establishing of the model and the constraints imposed. It has simulated the movement by software ANSYS, and gets the results which is consistent to the theoretical analysis. It accesses kinematical and dynamic characteristics for the mechanism, and provides the necessary foundation to analysis and design of the complex machinery.

The Effects of Layer-by-Layer Thickness and Fiber Volume Fraction Variation on the Mechanical Performance of a Pressure Vessel

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Emre Özaslan ◽  
Ali Yetgin ◽  
Bülent Acar ◽  
Volkan Coşkun ◽  
Tarık Olğar
Keyword(s):  
Finite Element ◽  
Pressure Vessel ◽  
Material Properties ◽  
Fiber Volume Fraction ◽  
Mechanical Performance ◽  
Volume Fraction ◽  
Element Model ◽  
Layer By Layer ◽  
Fiber Volume ◽  
Filament Wound

Abstract Due to high stiffness/weight ratio, composite materials are widely used in aerospace applications such as motor case of rockets which can be regarded as a pressure vessel. The most commonly used method to manufacture pressure vessels is the wet filament winding. However, the mechanical performance of a filament wound pressure vessel directly depends on the manufacturing process, manufacturing site environmental condition, and material properties of matrix and fiber. The designed pressure vessel may not be manufactured because of the mentioned issues. Therefore, manufacturing of filament wound composite structures are based on manufacturing experience and experiment. In this study, effects of layer-by-layer thickness and fiber volume fraction variation due to manufacturing process on the mechanical performance were investigated for filament wound pressure vessel with unequal dome openings. First, the finite element model was created for designed thickness dimensions and constant material properties for all layers. Then, the model was updated. The updated finite element model considered the thickness of each layer separately and variation of fiber volume fraction between the layers. Effects of the thickness and fiber volume fraction on the stress distribution along the motor axial direction were shown. Also hydrostatic pressurization tests were performed to verify finite element analysis in terms of fiber direction strain through the motor case outer surface. Important aspects of analyzing a filament wound pressure vessel were addressed for designers.

scholarly journals Finite Element Simulation of the Thermo-mechanical Response of Graphene Reinforced Nanocomposites

2018 ◽  
Vol 188 ◽  
pp. 01016
Author(s):  
Androniki S. Tsiamaki ◽  
Nick K. Anifantis
Keyword(s):  
Finite Element ◽  
Mechanical Behavior ◽  
Mechanical Response ◽  
Volume Fraction ◽  
Matrix Material ◽  
Continuum Theory ◽  
Element Model ◽  
Multilayer Graphene ◽  
Temperature Changes ◽  
The Matrix

The research for new materials that can withstand extreme temperatures and present good mechanical behavior is of great importance. The interest is highly focused on the utilization of composites reinforced by nanomaterials. To cope with this goal the present work studies the mechanical response of graphene reinforced nanocomposite structures subjected to temperature changes. A computational finite element model has been developed that accounts for both the reinforcement and the matrix material phases. The model developed is based on both the continuum theory and the molecular mechanics theory, for the simulation of the three different material phases of the composite, respectively, i.e. the matrix, the intermediate transition phase and the reinforcement. Considering this model, the mechanical response of an appropriate representative volume element of the nanocomposite is simulated under various temperature changes. The study involves different types of reinforcement composed from either monolayer or multilayer graphene sheets. Apart from the investigation of the behavior of a nanocomposite with each particular type of the reinforcement, comparisons are also presented between them in order to reveal optimized material combinations. The principal parameters taken into consideration, which contribute also to the mechanical behavior of the nanocomposite, are its size, the sheet multiplicity as well as the volume fraction.

MULTISCALE COMPUTATIONAL EVALUATION OF ELASTO-VISCOPLASTIC DEFORMATION BEHAVIOR OF AMORPHOUS POLYMER CONTAINING MICROSCOPIC HETEROGENEITY DURING UNIAXIAL TENSILE TEST

2010 ◽  
Vol 02 (03n04) ◽  
pp. 235-255 ◽  
Author(s):  
MAKOTO UCHIDA ◽  
NAOYA TADA
Keyword(s):  
Finite Element ◽  
Deformation Behavior ◽  
Volume Fraction ◽  
Amorphous Polymer ◽  
Element Model ◽  
Strength Distribution ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Viscoplastic Deformation ◽  
Heterogeneous Microstructures

The two-scale elasto-viscoplastic deformation behavior of amorphous polymer was investigated using the large deformation finite element homogenization method. In order to enable a large time increment for the simulation step in the plastic deformation stage, the tangent modulus method is introduced into the nonaffine molecular chain network theory, which is used to represent the deformation behavior of pure amorphous polymer. Two kinds of heterogeneous microstructures were prepared in this investigation. One was the void model, which contains uniformly or randomly distributed voids, and the other was the heterogeneous strength (HS) model, which contains a distribution of initial shear strength. In the macroscopic scale, initiation and propagation processes of necking during uniaxial tension were considered. The macroscopic nominal stress–strain relation was strongly characterized by the volume fraction and distribution of voids for the void model and by the width of the strength distribution for the HS model. Non-uniform deformation behaviors in microscopic and macroscopic scales are closely related to each other for amorphous polymers because continuous stretching and hardening in the localized zone of the microstructure brings about an increase in macroscopic deformation resistance. Furthermore, computational results obtained from the homogenization model are compared to those obtained from the full-scale finite element model, and the effect of the scale difference between microscopic and macroscopic fields is discussed.

scholarly journals Uncertainty Analysis of Piezoelectric Vibration Energy Harvesters Using a Finite Element Level-Based Maximum Entropy Approach

2020 ◽  
Author(s):  
X. Q. Wang ◽  
Yabin Liao ◽  
Marc P. Mignolet
Keyword(s):  
Finite Element ◽  
Excitation Frequency ◽  
Element Model ◽  
Vibration Energy ◽  
Adaptive Optimization ◽  
Analysis And Design ◽  
Energy Harvesters ◽  
Finite Element Software ◽  
The Mean ◽  
Piezoelectric Vibration

Abstract Quantifying effects of system-wide uncertainties (i.e., affecting structural, piezoelectric, and/or electrical components) in the analysis and design of piezoelectric vibration energy harvesters has recently been emphasized. The present investigation proposes first a general methodology to model these uncertainties within a finite element model of the harvester obtained from an existing finite element software. Needed from this software are the matrices relating to the structural properties (mass, stiffness), the piezoelectric capacitance matrix, as well as the structural-piezoelectric coupling terms of the mean harvester. The thermal analogy linking piezoelectric and temperature effects is also extended to permit the use of finite element software that do not have piezoelectric elements but include thermal effects on structures. The approach is applied to a beam energy harvester. Both weak and strong coupling configurations are considered and various scenarios of load resistance tuning are considered, i.e., based on the mean model, for each harvester sample, or based on the entire set of harvesters. The uncertainty is shown to have significant effects in all cases even at a relatively low level and these effects are dominated by the uncertainty on the structure vs. the one on the piezoelectric component. The strongly coupled configuration is shown to be better as it is less sensitive to the uncertainty and its variability in power output can be significantly reduced by the adaptive optimization, and the harvested power can even be boosted if the target excitation frequency falls into the power saturation band of the system.

A Finite Element Approach for Study of Wave Attenuation Characteristics of Epoxy Polymer Composite

2018 ◽  
Author(s):  
Shank S. Kulkarni ◽  
Alireza Tabarraei ◽  
Pratik P. Ghag
Keyword(s):  
Finite Element ◽  
Polymer Composite ◽  
Polymer Matrix ◽  
Wave Attenuation ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Element Model ◽  
Loading Frequency ◽  
Macroscopic Properties ◽  
Attenuation Characteristics

The properties of the inclusions, viz. size, shape, and distribution significantly affect macroscopic properties of a polymer composite. Finite element (FE) modeling provides a viable approach for investigating the effects of the inclusions on the macroscopic properties of the polymer composite. In this paper, finite element method is used to investigate ultrasonic wave propagation in polymer matrix composite with a dispersed phase of inclusions. The finite element models are made up of three phases; viz. the polymer matrix, inclusions (micro constituent), and interphase zones between the inclusions and the polymer matrix. The analysis is performed on a three dimensional finite element model and the attenuation characteristics of ultrasonic longitudinal waves in the matrix are evaluated. The attenuation in polymer composite is investigated by changing the size, volume fraction of inclusions, and addition of interphase layer. The effect of loading frequency of the wave on the attenuation characteristics is also studied by varying the frequency in the range of 1–4 MHz. Results of the test revealed that higher volume fraction of inclusions gave higher attenuation in the polymer composite as compared to the lower volume fraction model. Smaller size of inclusions are preferred over larger size as they give higher wave attenuation. It was found that the attenuation characteristics of the polymer composite are better at higher frequencies as compared to lower frequencies. It is also concluded that the interphase later plays a significant role in the attenuation characteristics of the composite.

Fully Coupled Three-Scale Finite Element Model for the Mechanical Response of a New Bio-Inspired Composite

2011 ◽  
Author(s):  
Erick I. Saavedra Flores ◽  
Senthil Murugan ◽  
Michael I. Friswell ◽  
Eduardo A. de Souza Neto
Keyword(s):  
Finite Element ◽  
Magnesium Alloy ◽  
Finite Element Model ◽  
Large Scale ◽  
Mechanical Response ◽  
Volume Fraction ◽  
Element Model ◽  
Crystalline Cellulose ◽  
Gauss Point ◽  
Fully Coupled

This paper proposes a fully coupled three-scale finite element model for the mechanical description of an alumina/magnesium alloy/epoxy composite inspired in the mechanics and architecture of wood cellulose fibres. The constitutive response of the composite (the large scale continuum) is described by means of a representative volume element (RVE, corresponding to the intermediate scale) in which the fibre is represented as a periodic alternation of alumina and magnesium alloy fractions. Furthermore, at a lower scale the overall constitutive behavior of the alumina/magnesium alloy fibre is modelled as a single material defined by a large number of RVEs (the smallest material scale) at the Gauss point (intermediate) level. Numerical material tests show that the choice of the volume fraction of alumina based on those volume fractions of crystalline cellulose found in wood cells results in a maximisation of toughness in the present bio-inspired composite.

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