Michael Szelwis: "Particle-reinforced composites simulated by cohesive discrete elements" — различия между версиями

Материал из Department of Theoretical and Applied Mechanics
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== Project Overview ==
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[[Файл:composite.png|thumb|200px|Microscopic photograph of a TiO2-PMMA composite]]
[[Файл:microscope_ceramic_polymer_comp.jpg|thumb|200px|Microscopic photograph the ceramic-polymer-composite]]
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[[Файл:bending2.png|thumb|200px|Bending test of simulated TiO2-PMMA specimen]]
For the research on a ceramic-polymer-composite (TiO2 in a PMMA matrix) with very high content of ceramic particles a numerical model is being investigated. To simulate the nonlinear deformation due to indentation a discrete element approach has been chosen with each ceramic particle being represented by one particle in the simulation. Several models for the interaction of the ceramic particles with one another as well as with the polymeric matrix, such as cohesion and physical bonds, are being tested using the software package EDEM and are also being compared with experimental results.
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[[Файл:bending_results.png|thumb|200px|Load-displacement behaviour during bending using cohesive DEM]]
  
== Previous Work ==
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== Abstract ==
[[Файл:old_bond_specimen.jpg|thumb|200px|Specimen of previous work with bonds representing polimeric matrix]]
 
  
Simulating the mechanical behaviour of the investigated material, Hertzian contacts between the particles were combined with EDEM's default bond model representing the polimeric matrix. First tests revealed qualitative accordance to experimental results within the region of elastic deformation of the specimen. It was shown that a stiffer material used for the polymeric matrix, which has been modelled by bonds with a larger Young's modulus, leads to a higher stiffness of the specimen.
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Interest in the simulation of material properties using numerical methods is increasing, as laboratory experiments and tests are often expensive and generally limited in flexibility.
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In this work, a DEM-approach is presented which simulates the elastic-plastic behavior of particle reinforced composites. While in the past, Discrete Element Modeling (DEM) has successfully been used to simulate elasticity and brittleness of materials, this modified approach based on the principals of Molecular Dynamics suggests a DEM-approach for modeling plastic materials.
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Simulations of a ceramic-polymer composite (TiO2-particles in a matrix PMMA) subjected to varying load conditions are presented. While Hertz-Mindlin forces are inherent in the algorithm, two variants of modeling particle attraction, particle bonds and cohesion, are applied individually. According to the results of this work, the new cohesive DEM is in good qualitative agreement with the behavior of particle-reinforced composites and therefore preferred. Ideas are presented for a modification of the computer algorithm to calibrate this cohesive DEM approach, aiming at an effective numerical method which can support experimental research on particle-reinforced composites.
  
== Results ==
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== Complete Article ==
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[[Медиа:CohesiveDEM_DA_MSzelwis_Dez2011.pdf]]
  
== Outlook ==
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== См. также ==
* Comparison of the results with experimental data
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* Examining the suitability using the model for investigation of hirarchic materials
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*[[Michael Szelwis]]
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*[[Гамбургский проект]]
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[[Category: Студенческие проекты]]
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[[Category: Механика дискретных сред]]

Текущая версия на 18:57, 16 мая 2012

Microscopic photograph of a TiO2-PMMA composite
Bending test of simulated TiO2-PMMA specimen
Load-displacement behaviour during bending using cohesive DEM

Abstract[править]

Interest in the simulation of material properties using numerical methods is increasing, as laboratory experiments and tests are often expensive and generally limited in flexibility. In this work, a DEM-approach is presented which simulates the elastic-plastic behavior of particle reinforced composites. While in the past, Discrete Element Modeling (DEM) has successfully been used to simulate elasticity and brittleness of materials, this modified approach based on the principals of Molecular Dynamics suggests a DEM-approach for modeling plastic materials. Simulations of a ceramic-polymer composite (TiO2-particles in a matrix PMMA) subjected to varying load conditions are presented. While Hertz-Mindlin forces are inherent in the algorithm, two variants of modeling particle attraction, particle bonds and cohesion, are applied individually. According to the results of this work, the new cohesive DEM is in good qualitative agreement with the behavior of particle-reinforced composites and therefore preferred. Ideas are presented for a modification of the computer algorithm to calibrate this cohesive DEM approach, aiming at an effective numerical method which can support experimental research on particle-reinforced composites.

Complete Article[править]

Медиа:CohesiveDEM_DA_MSzelwis_Dez2011.pdf

См. также[править]