Finite Element Analysis of Multiphase Viscoelastic Solids

1992 ◽  
Vol 59 (4) ◽  
pp. 730-737 ◽  
Author(s):  
L. C. Brinson ◽  
W. G. Knauss
Keyword(s):  
Finite Element ◽  
Volume Fraction ◽  
Matrix Material ◽  
Numerical Procedure ◽  
Element Model ◽  
Analytical Models ◽  
Frequency Range ◽  
Element Analysis ◽  
The Matrix ◽  
Composite Moduli

The properties of composite solids containing multiple, viscoelastic phases are studied numerically. The dynamic correspondence principle of viscoelasticity is utilized in a finite element model to solve boundary value problems for obtaining global complex moduli of the composite. This numerical procedure accounts for the coupled interactive deformation of the phases and thus the resultant accuracy is limited only by that of finite element analyses in general. The example composite considered in this study contains cylindrical viscoelastic inclusions embedded in a viscoelastic matrix. This investigation focuses on the global composite moduli and their relationship to the individual phase properties as a function of volume fraction. A given phase material is shown to have differing effects on the composite properties, depending on whether it is the continuous or the included phase: In general, the composite moduli are dominated by the matrix material. Comparison is made with two simple analytical models for global effective moduli of composites. “Upper Bounds” reproduce the behavior over the whole frequency range when the matrix is the “stiffer” of the two solids while the “lower bond” associates with the converse arrangement, also over the whole frequency range. The nature of time-temperature behavior of multiphase composite materials is examined in a companion paper.

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.

Finite Element Analysis of SiCp/Al Model of Unit Cell during Ultrasonic Vibration Scratching

2016 ◽  
Vol 693 ◽  
pp. 1022-1029
Author(s):  
G.Q. Liang ◽  
Ping Fa Feng ◽  
Jian Fu Zhang
Keyword(s):  
Finite Element ◽  
Maximum Amplitude ◽  
Element Model ◽  
Ultrasonic Frequency ◽  
Frequency Range ◽  
Element Analysis ◽  
Scale Modeling ◽  
Sic Particles ◽  
Significant Damage ◽  
Extent Of Damage

In this paper, finite element model of SiCp /Al single cell body and single diamond particles were established by cross-scale modeling method. The results shows that the extent of damage of SiC particles increased with the increase of amplitude and frequency; The integrity of SiC particles are still better under the ultrasonic frequency 20000 Hz and the maximum amplitude 5um,so the optimal frequency range of ultrasonic scratch is (20000-30000)Hz. As for 22000 Hz, the integrity of SiC particles was better under the amplitude 4um,while the SiC particles have a significant damage in the border area under the amplitude 5um,so the best frequency and amplitude for ultrasonic scratches are: 22000 Hz and 4 um.

Modified Anisotropic Gurson Yield Criterion for Porous Ductile Sheet Metals

2000 ◽  
Vol 123 (4) ◽  
pp. 409-416 ◽  
Author(s):  
W. Y. Chien ◽  
J. Pan ◽  
S. C. Tang
Keyword(s):  
Finite Element ◽  
Closed Form ◽  
Yield Criterion ◽  
Plastic Anisotropy ◽  
Matrix Material ◽  
Plastic Behavior ◽  
Computational Results ◽  
Sheet Metals ◽  
Element Analysis ◽  
The Matrix

The influence of plastic anisotropy on the plastic behavior of porous ductile materials is investigated by a three-dimensional finite element analysis. A unit cell of cube containing a spherical void is modeled. The Hill quadratic anisotropic yield criterion is used to describe the matrix normal anisotropy and planar isotropy. The matrix material is first assumed to be elastic perfectly plastic. Macroscopically uniform displacements are applied to the faces of the cube. The finite element computational results are compared with those based on the closed-form anisotropic Gurson yield criterion suggested in Liao et al. 1997, “Approximate Yield Criteria for Anisotropic Porous Ductile Sheet Metals,” Mech. Mater., pp. 213–226. Three fitting parameters are suggested for the closed-form yield criterion to fit the results based on the modified yield criterion to those of finite element computations. When the strain hardening of the matrix is considered, the computational results of the macroscopic stress-strain behavior are in agreement with those based on the modified anisotropic Gurson’s yield criterion under uniaxial and equal biaxial tensile loading conditions.

Finite Element Analysis of the Effect of Cutting Speed on the Orthogonal Turning of A359/SiCp MMC

2016 ◽  
Vol 852 ◽  
pp. 304-310
Author(s):  
M.M. Thamizharasan ◽  
Y.J. Nithiya Sandhiya ◽  
K.S. Vijay Sekar ◽  
V.V. Bhanu Prasad
Keyword(s):  
Finite Element ◽  
Matrix Material ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Fe Model ◽  
Element Analysis ◽  
Damage And Fracture ◽  
Orthogonal Turning ◽  
The Matrix ◽  
Cutting Speeds

The application of Metal Matrix Composite (MMC) has been increasing due to its superior strength and wear characteristics but the major challenge is its poor machinability due to the presence of reinforcement in the matrix which is a hindrance during machining. The material behaviour during machining varies with respect to input variables. In this paper the effect of cutting speed during the orthogonal turning of A359/SiCp MMC with TiAlN tool insert is analysed by developing a 2D Finite Element (FE) model in Abaqus FEA code. The FE model is based on plane strain formulation and the element type used is coupled temperature displacement. The matrix material is modeled using Johnson–Cook (J-C) thermal elastic–plastic constitutive equation and chip separation is simulated using Johnson–Cook’s model for progressive damage and fracture with parting line. Particle material is considered to be perfectly elastic until brittle fracture. The tool is considered to be rigid. The FE model analyses the tool interaction with the MMC and its subsequent effects on cutting forces for different cutting speeds and feed rates. The chip formation and stress distribution are also studied. The FE results are validated with the experimental results at cutting speeds ranging from 72 – 188 m/min and feed rates ranging from 0.111 – 0.446 mm/rev at constant depth of cut of 0.5mm.

scholarly journals Finite Element Analysis of Coffea arabica L. var. Colombia Fruits for Selective Detachment Using Forced Vibrations

Vibration ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 207-219 ◽  
Author(s):  
Hector Tinoco ◽  
Fabio Peña
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Coffea Arabica ◽  
Numerical Procedure ◽  
Final Conclusion ◽  
Frequency Range ◽  
Element Analysis ◽  
Forced Vibration Analysis ◽  
Dynamic Excitations ◽  
Coffea Arabica L

This study provides a forced vibration analysis to evaluate the stresses at the pedicel interfaces of the fruit-peduncle system of Coffea arabica L. var. Colombia by means of finite element analysis. The real topology of the fruit-peduncle system was developed from a proposed numerical procedure to complete a dynamic analysis. The Young’s modulus of the fruit was approximated from firmness indices for all stages of ripening. Numerical computations were performed in the frequency range of 0 to 400 Hz and three vibration modes were identified in this bandwidth. Results show that the second natural frequency (128 Hz) is acceptable for stimulating the detachment of ripe fruits because the fruit-pedicel-peduncle system induces bending in the fruit interface. As a final conclusion, we determine that dynamic excitations between 120 and 150 Hz could permit selective stimulus of ripe fruits, since other ripening stages were not stimulated in this frequency range.

Harmonic stress analysis on Coffea arábica L. var. Colombia fruits in order to stimulate the selective detachment: A finite element analysis

SIMULATION ◽  
2017 ◽  
Vol 94 (2) ◽  
pp. 163-174 ◽  
Author(s):  
Hector A Tinoco ◽  
Fabio M Peña
Keyword(s):  
Finite Element ◽  
Stress Analysis ◽  
Coffea Arabica ◽  
Poisson Ratio ◽  
Numerical Procedure ◽  
Analytical Models ◽  
Element Analysis ◽  
Ripening Stages ◽  
Force Signal ◽  
Coffea Arabica L

This study shows a finite element harmonic stress analysis to evaluate the stress performance at the pedicel interface of a fruit–peduncle system of Coffea arábica L. var. Colombia plants. The aim was to study detachment of fruits subjected to mechanical vibrations. A model of the coffee fruit–peduncle system is designed computationally to reproduce its topology in all ripening stages using a proposed numerical procedure. Young’s modulus, Poisson ratio, and density were adjusted using analytical models for all ripening stages. The glomerulus of three fruits in different ripening stages was proposed and these were combined in four groups. Based on a detachment model, it was verified which fruit was detached first when a chirp force signal was applied on each glomerulus. Results indicated that dynamic excitations applied in between 130 to 150 Hz detached only ripe fruits, since fruits that were in other ripening stages were not stimulated until detachment in that bandwidth.

Research on Strain Transfer of Embedded BOTDA Sensors Analyzed by FEM

2013 ◽  
Vol 357-360 ◽  
pp. 1473-1479
Author(s):  
Yan Qiao ◽  
Chuan Zhi Sun ◽  
Biao Zhang
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Finite Element Model ◽  
Matrix Material ◽  
Element Model ◽  
Analysis Software ◽  
Element Analysis ◽  
Strain Transfer ◽  
Fiber Coating ◽  
Bonding Material

in this paper, the theory of strain transfer of embedded BOTDA sensors was introduced. For the sensing fiber with coating and jacket used in project, its finite element model was built by ANSYS infinite element analysis software. And for the embedded fiber, the influences affected by elastic modulus and thickness of the fiber coating and jacket and elastic modulus of matrix material were analyzed. For the surface bonded fiber, the influences affected by elastic modulus, width and thickness of the bonding material were analyzed, and the results were compared with the results of theory.

Initial Imperfection Models for Segments of Line Pipe

2005 ◽  
Vol 128 (4) ◽  
pp. 322-329 ◽  
Author(s):  
Alfred B. Dorey ◽  
David W. Murray ◽  
J. J. Roger Cheng
Keyword(s):  
Finite Element ◽  
Initial Imperfection ◽  
Bending Moment ◽  
Element Model ◽  
Mean Value ◽  
Analytical Models ◽  
Element Analysis ◽  
Line Pipe ◽  
Initial Imperfections ◽  
Experimental Behavior

Initial imperfections have long been acknowledged as having an effect on the behavior of shell structures, affecting both the global and local behavior. Yet, despite their significance, initial imperfections are rarely included in analytical models for pipelines. This is usually because of the complicated nature of initial imperfections, the difficulty in measuring them, and the small amount of available literature that describes their geometry. Some recent investigations at the University of Alberta in Edmonton have focused on the effect of initial imperfections on the behavior of segments of line pipe. Imperfections measured across the inside surface of pipe test specimens were incorporated into a finite element model that was developed to predict the experimental behavior of the specimens tested under combined loads of internal pressure, axial load and bending moment. Test-to-predicted ratios for the load carrying capacity of the test specimens had a mean value of 1.035 with a coefficient of variation of 0.047. The improvements in the accuracy of the finite element analysis models that include the initial imperfection pattern indicate their importance in modeling the experimental behavior. Once the importance of initial imperfections was established, idealized patterns were developed to simplify numerical modeling. This paper presents the results of different patterns investigated for both plain and girth-welded segments of line pipe and provides recommended simplified assumed initial imperfection patterns.

Strength Evaluation of Polymer Composite Spur Gear by Finite Element Analysis

2008 ◽  
Author(s):  
Mohammad Robiul Hossan ◽  
Zhong Hu
Keyword(s):  
Finite Element ◽  
Polymer Composite ◽  
Volume Fraction ◽  
Gear Tooth ◽  
Axial Stress ◽  
High Stress ◽  
Element Model ◽  
Simulation Method ◽  
Spur Gear ◽  
Element Analysis

Modern advanced polymer composite materials have opened a new level of noiseless, lubricant free, high resilience and precision gearing in power and motion transmission. The proper understanding and evaluation of gear strength and performance is an important prerequisite for any reliable application. In this paper, a 20% short glass fiber reinforced nylon66 spur gear fabricated by injection molding has been carefully investigated. A three-dimensional finite element model was used to simulate the multi-axial stress-strain behaviors of a gear tooth under the dynamic load for a complete working cycle with a special geometry, operating condition, fiber orientation and volume fraction. The strength of composite gears has been compared with isotropic un-reinforced nylon66 and steel gears. The tooth root region of a gear which usually experiences high stress and potential to failure has been carefully investigated. This computer simulation method can be used as a useful tool for evaluating strength and predicting failure of the polymer composite gears.

Finite Element Analysis on Residual Stress of Laser Brazing Diamond Wheel

2013 ◽  
Vol 712-715 ◽  
pp. 739-742 ◽  
Author(s):  
Zhi Bo Yang ◽  
Pei Fei Luo
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Element Model ◽  
Processing Parameters ◽  
Diamond Wheel ◽  
Laser Brazing ◽  
Element Analysis ◽  
The Matrix ◽  
Simulation And Experiment ◽  
Field Element

The purpose of this paper is to simulate the residual field of laser brazing by FEM of ANSYS. The 2-D coupled field element is elected to create finite element model. The brazing experiments have been done by means of 45steel which is the matrix and Ni-Cr solder and the residual stress of the diamond wheel has been measured by Raman method. The results of measure show that the maximum stress value is less strength of diamond. The residual stress distribution is basically identical between the results of simulation and experiment. According to this paper, it is possible to decrease the costs of study by selecting reasonable processing parameters on laser brazing.

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