scholarly journals Numerical Simulations of Clay Tiles Compression

2012 ◽  
Vol 504-506 ◽  
pp. 1403-1408 ◽  
Author(s):  
Jérémie Vignes ◽  
Fabrice Schmidt ◽  
Gilles Dusserre ◽  
Olivier de Almeida ◽  
Jean Frédéric Dalmasso
Keyword(s):  
Numerical Model ◽  
Tensile Stress ◽  
Numerical Simulations ◽  
Compression Tests ◽  
Rheological Study ◽  
Constitutive Parameters ◽  
Actual Geometry ◽  
Clay Tiles ◽  
Force Displacement ◽  
Tribological Parameters

During the pressing step, the clay tiles undergo stresses which result in the appearance of defects. A rheological study, based on free compression tests, allowed to confirm the Elasto-visco-plastic behaviour of the clay. The different constitutive parameters were estimated by fitting the force-displacement experimental curves using the optimisation algorithm (ES Metamodel) implanted in the commercial software Forge 2009®. The influence of the tribological parameters was studied using squeezing numerical simulations of a full tile. The numerical model was validated with experimental squeezing test of technological specimen with a tile lug. Then, we have compared experimental force with the numerical one and deduced that the clay/tool interface is not perfectly sliding. A friction Tresca’s law was used to model the clay/tool interface. Numerical results showed that the actual geometry of tile lug didn’t allow to form correctly the tile. Several areas undergo tensile stress, air traps ,... A new geometry of tile lug was proposed in order to limit this phenomenon. Using a simplified defect criteria (Latham and Cockroft), the numerical model allowed to locate the areas where there is a risk of crack.

scholarly journals Effect of Moisture on the Behaviour of an Extruded Clay Paste

2013 ◽  
Vol 554-557 ◽  
pp. 2230-2236
Author(s):  
Jérémie Vignes ◽  
Fabrice Schmidt ◽  
Gilles Dusserre ◽  
Jean Frédéric Dalmasso
Keyword(s):  
Inverse Analysis ◽  
Linear Models ◽  
Raw Materials ◽  
Industrial Process ◽  
Rheological Behaviour ◽  
Rheological Parameters ◽  
Compression Tests ◽  
State Of Stress ◽  
Constitutive Parameters ◽  
Force Displacement

In the industrial process, the moisture of the clay sheet obtained by extrusion and pressed to form a tile varies in time. It depends on the nature and the mixing of the raw materials during the production. In order to model and undersand the influence of the moisture on the pressing step, it is necessary to determine the parameters of the rheological and tribological laws. A study of the rheological behaviour, based on free compression tests on cylinder samples, allowed to use an elasto-visco-plastic behaviour for the extruded clay paste. The different constitutive parameters were estimated by an inverse analysis based on the experimental force/displacement curves. The identification was performed with the optimisation algorithm implemented in the commercial software Forge® 2009. The influence of the water content in the paste on the rheological parameters was identified and fitted using linear models. The friction factor was measured from tests on a rectilign tribometer. To understand the influence of the moisture, we simulated a compression test, using Forge® involving the shaping of a tile lug. This geometry is representative of the state of stress during the pressing of the tile, in an area currently sujected to defects. The numerical model show that an increase of eighteen percent of the moisture allows to decrease by half the pressing force.

A New Tire Model to Predict Vibration Emission of Counterbalance Trucks

2000 ◽  
Vol 28 (2) ◽  
pp. 119-137 ◽  
Author(s):  
P. Lemerle ◽  
P. Mistrot
Keyword(s):  
Numerical Model ◽  
Numerical Simulations ◽  
Close Agreement ◽  
Industrial Sector ◽  
Tire Model ◽  
Suspension Systems ◽  
Truck Tires ◽  
Pneumatic Tires

Abstract Counterbalance trucks are machines in widespread use in every industrial sector. Unlike cars, they are not designed with suspension systems. Consequently, they are considered to be high vibrating vehicles. Nevertheless, like suspension seats, tires can be selected as suspension parts. This paper presents a new numerical model for the analysis of the vibratory behavior of counterbalance truck tires. This model was intended to be a part of a fork lift truck model, including axles, chassis, and cabin. All the results reported here show a close agreement between measurements and numerical simulations. Thus, it can predict the vibration emission values at the driving position and is used to compare the efficiency of solid tires with pneumatic tires in terms of transmitted vibration levels.

scholarly journals Wind shear over the Nice Côte d'Azur airport: case studies

2013 ◽  
Vol 13 (9) ◽  
pp. 2223-2238 ◽  
Author(s):  
A. Boilley ◽  
J.-F. Mahfouf
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Numerical Simulations ◽  
Wind Shear ◽  
Horizontal Wind ◽  
Wind Profiler ◽  
Measurement Campaign ◽  
Wind Lidar ◽  
Real Time Applications ◽  
Wind Shears

Abstract. The Nice Côte d'Azur international airport is subject to horizontal low-level wind shears. Detecting and predicting these hazards is a major concern for aircraft security. A measurement campaign took place over the Nice airport in 2009 including 4 anemometers, 1 wind lidar and 1 wind profiler. Two wind shear events were observed during this measurement campaign. Numerical simulations were carried out with Meso-NH in a configuration compatible with near-real time applications to determine the ability of the numerical model to predict these events and to study the meteorological situations generating an horizontal wind shear. A comparison between numerical simulation and the observation dataset is conducted in this paper.

Effect of micro in-plane fiber waviness on compressive properties of unidirectional fabric composites

2017 ◽  
Vol 52 (15) ◽  
pp. 2065-2074 ◽  
Author(s):  
Bo Wang ◽  
Nobuhide Uda ◽  
Kousei Ono ◽  
Hiroto Nagai
Keyword(s):  
Compressive Strength ◽  
Numerical Model ◽  
Tensile Stress ◽  
Compressive Modulus ◽  
Two Dimensional ◽  
Compressive Properties ◽  
Fiber Waviness ◽  
Experimental Part ◽  
Fabric Composites ◽  
Vartm Process

In this paper, a combination of experimentation and analysis is used to study the effect of micro in-plane fiber waviness on the compressive properties of unidirectional fabric composites. The experimental part includes a measurement of the micro in-plane fiber waviness in two types of unidirectional fabrics, manufacturing composites with each unidirectional fabric via VaRTM process and tests for establishing the compressive modulus and strengths of the composites. The compressive strengths were confirmed to be affected by the micro in-plane fiber waviness, but the compressive modulus was not. Furthermore, a two-dimensional numerical model is proposed to explain our experimental results. The numerical results indicate that the tensile stress (owing to the micro in-plane fiber waviness) and compressive stress along the weft and warp directions, respectively, of the composite lead to reductions in the compressive strength.

Multifidelity Recursive Cokriging for Dynamic Systems' Response Modification

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Luigi Bregant ◽  
Lucia Parussini ◽  
Valentino Pediroda
Keyword(s):  
Numerical Model ◽  
Numerical Simulations ◽  
Dynamic Systems ◽  
System Optimization ◽  
The Other ◽  
Experimental Measurements ◽  
Reciprocal Influence ◽  
Tests And Measurements ◽  
Invaluable Tool ◽  
Mixed Approach

In order to perform the accurate tuning of a machine and improve its performance to the requested tasks, the knowledge of the reciprocal influence among the system's parameters is of paramount importance to achieve the sought result with minimum effort and time. Numerical simulations are an invaluable tool to carry out the system optimization, but modeling limitations restrict the capabilities of this approach. On the other side, real tests and measurements are lengthy, expensive, and not always feasible. This is the reason why a mixed approach is presented in this work. The combination, through recursive cokriging, of low-fidelity, yet extensive, numerical model results, together with a limited number of highly accurate experimental measurements, allows to understand the dynamics of the machine in an extended and accurate way. The results of a controllable experiment are presented and the advantages and drawbacks of the proposed approach are also discussed.

scholarly journals Fish Cells, a new zero Poisson’s ratio metamaterial—Part I: Design and experiment

2020 ◽  
Vol 31 (13) ◽  
pp. 1617-1637
Author(s):  
Mohammad Naghavi Zadeh ◽  
Iman Dayyani ◽  
Mehdi Yasaee
Keyword(s):  
Numerical Analysis ◽  
Numerical Model ◽  
Poisson’S Ratio ◽  
Structural Integrity ◽  
Structural Response ◽  
Poisson's Ratio ◽  
Experimental Investigations ◽  
Fish Cells ◽  
Force Displacement ◽  
Model Approach

A novel cellular mechanical metamaterial called Fish Cells that exhibits zero Poisson’s ratio in both orthogonal in-plane directions is proposed. Homogenization study on the Fish Cells tessellation is conducted and substantially zero Poisson’s ratio behavior in a homogenized tessellation is shown by numerical analysis. Experimental investigations are performed to validate the zero Poisson’s ratio feature of the metamaterial and obtain force–displacement response of the metamaterial in elastic and plastic zone. A detailed discussion about the effect of the numerical model approach and joints on the structural response of the metamaterial is presented. Morphing skin is a potential application for Fish Cells metamaterial because of the integration benefits of zero Poisson’s ratio design. The structural integrity of the Fish Cells is investigated by studying the stiffness augmentation under tension and in presence of constraints on transverse edges. Finally, geometrical enhancements for improved integrity of the Fish Cells are presented that result in substantially zero stiffness augmentation required for morphing skins.

Input Data Determination for Large Strain Simulations

2015 ◽  
Vol 751 ◽  
pp. 124-130
Author(s):  
Jan Džugan ◽  
Martina Maresova ◽  
Jan Nachazel
Keyword(s):  
Numerical Simulations ◽  
Input Data ◽  
Large Strain ◽  
Fem Simulation ◽  
Material Behavior ◽  
Production Costs ◽  
Image Correlation ◽  
Compression Tests ◽  
Material Models ◽  
Strain Measurements

Numerical simulations are widely used for forming processes optimizations nowadays. They significantly contribute to improvement of forgings quality and production costs reduction. The crucial points of the numerical simulations are material input data and implemented material models. The paper is dealing with overview of methods for the input data measurement. There are discussed tests with various options of strain measurements as well as modifications of compression tests. Part of the paper is dealing with 3D strain measurements by Digital Image Correlation (DIC) enabling local strains measurements. DIC enables direct comparison of strains experimentally measured and strains obtained by numerical simulations, which is going to be presented. Finally, possibilities of complex material description considering plastic damage are presented. The last approach is the most accurate providing the most information on material behavior for FEM simulation, the procedure includes measurements on samples of various geometries with various stress strain conditions. Examples of sample sets for these measurements are shown here together with material models describing multiaxial plastic flow and damage.

scholarly journals Particle Compression Test: A Key Step towards Tailoring of Feedstock Powder for Cold Spraying

Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 458 ◽  
Author(s):  
Hamid Assadi ◽  
Frank Gärtner
Keyword(s):  
Cold Spray ◽  
Cold Spraying ◽  
Compression Tests ◽  
Feedstock Powder ◽  
Design And Manufacturing ◽  
Present Case Study ◽  
Force Displacement ◽  
Subsequent Comparison ◽  
The Ideal

Cold spray is on the way to becoming a mainstream technology for coating and additive manufacturing processes. While there have been many advances in various aspects of this technology, the question of tailoring the ‘ideal’ feedstock powder for cold spraying has remained open. In particular, the mechanical strength and its dependence on the particle size, which are amongst the most relevant properties of the feedstock powder for cold spraying, are rarely covered when reporting powder specifications. This is mainly because of the lack of standardised methods of characterisation for these specific properties. In the present case study, we demonstrate how compression tests of single Inconel 718 particles by using a modified nanoindenter can address this central question. Data analyses are supported by finite element modelling of particle compression for a range of plastic behaviours. The results of simulation are then stored in the form of a surrogate model for subsequent comparison with the experimental data. Thus, the ultimate tensile strength and the size of the examined particles are calculated directly from the measured force-displacement data. The paper will also discuss how this information can be used to optimise cold spraying, and so, unveils a key step towards the design and manufacturing of cold-spray-specific feedstock powder.

A FEA Simulation Model for Thin-Walled C-Section Composite Beam Assembling With R-Angle Deviation

2014 ◽  
Author(s):  
Hua Wang ◽  
Suo Si
Keyword(s):  
Numerical Model ◽  
Composite Beam ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Element Model ◽  
Load Level ◽  
Compression Tests ◽  
Accurate Analysis ◽  
Angle Deviation ◽  
Thin Walled

There are unavoidable deviations, such as shrinkage and distortions, in the composite detail parts production due to the complexity of composites fabrication. Interests in the assembly analysis of composite beams have led to a need for more accurate analysis especially in the case of fabrication deviations. This work proposes a numerical finite element model of thin-walled C-section composite beam with R-angle deviation for assembling. The rule of Hashin failure combined with cohesive element is applied to study the mechanical performance of the fiber and matrix (implemented as user subroutine UMAT in ABAQUS) while positioning and clamping. Tension and compression tests are carried out based on available standards to determine the C-section beam behavior under load. The testing data validates the proposed numerical model. The numerical model captures the experimentally obtained results with minimal error, and predicts the failure modes successfully. The proposed model allows to determine accurately the first failure location and the associated load level. It will enhance the understanding of the composite components pre-loading analysis, and help systematically improving the composites assembling efficiency in civil aircraft industry.

scholarly journals Construction of a numerical model of suspension in a numerical simulation of sedimentation

2018 ◽  
Vol 46 ◽  
pp. 00011
Author(s):  
Krzysztof Kołodziejczyk
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Numerical Simulations ◽  
Particle Composition ◽  
Polydisperse Particle ◽  
Multiphase Systems ◽  
The Moment ◽  
Definition Of ◽  
Selection Of ◽  
The Way

Modeling of multiphase systems, which includes suspensions, is an issue that is continually developed. There are no procedures at the moment that would clearly determine the way in which suspension is defined in numerical simulations. The article presents an analysis of the selection of a numerical model and the definition of the suspension with a polydisperse particle composition.

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