scholarly journals Status and Challenges in Homogenization Methods for Lattice Materials

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 605
Author(s):  
Jacobs Somnic ◽  
Bruce W. Jo
Keyword(s):  
Numerical Approach ◽  
Raw Material ◽  
Lattice Structures ◽  
Element Analysis ◽  
Computational Tools ◽  
Lattice Materials ◽  
Comprehensive Survey ◽  
Homogenization Methods ◽  
Rapid Processing ◽  
Numerical Approaches

Lattice structures have shown great potential in that mechanical properties are customizable without changing the material itself. Lattice materials could be light and highly stiff as well. With this flexibility of designing structures without raw material processing, lattice structures have been widely used in various applications such as smart and functional structures in aerospace and computational mechanics. Conventional methodologies for understanding behaviors of lattice materials take numerical approaches such as FEA (finite element analysis) and high-fidelity computational tools including ANSYS and ABAQUS. However, they demand a high computational load in each geometry run. Among many other methodologies, homogenization is another numerical approach but that enables to model behaviors of bulk lattice materials by analyzing either a small portion of them using numerical regression for rapid processing. In this paper, we provide a comprehensive survey of representative homogenization methodologies and their status and challenges in lattice materials with their fundamentals.

scholarly journals Study of rail-wheel contact problem by analytical and numerical approaches

2021 ◽  
Vol 1201 (1) ◽  
pp. 012035
Author(s):  
G G Sirata ◽  
H G Lemu ◽  
K Waclawiak ◽  
Y D Jelila
Keyword(s):  
Finite Element ◽  
Contact Problems ◽  
Material Model ◽  
Maximum Load ◽  
Numerical Approach ◽  
Elastoplastic Material ◽  
Element Analysis ◽  
Hertz Theory ◽  
Elliptical Contact ◽  
Numerical Approaches

Abstract This study presents the rail wheel contact problems under normal and tangential categories. Both analytical and numerical approaches were used for modelling, where the analytical approach assumed elliptical contact patches based on the Hertz theory. In the numerical approach, 3D finite element models were used to investigate non-elliptical contact patches. The only elastic material model was considered in the case of Hertz theory. However, in the case of finite element analysis, both elastic and elastoplastic material models were used to simulate the material's behavior under the applied load. The elastoplastic material model was used to determine the amount of stress at which the plastic deformation starts, which enables determining the rail wheel's critical load. The commercial software ABAQUS was employed for 3D modeling and contact stress analysis. The study shows maximum stress at 3 mm from the rail wheel contact surface when the maximum load of 85 kN is applied. This initiates the cracks in the subsurface and causes the portion of the rail wheel to break off in the form of spalling after a certain time.

scholarly journals Geochemistry and Mineralogy of Ice-Dammed Lake Sediments of the Lębork Deposit

2021 ◽  
Author(s):  
Radosław Rogoziński ◽  
Alina Maciejewska
Keyword(s):  
Chemical Composition ◽  
Lake Sediments ◽  
Inductively Coupled Plasma ◽  
Mineralogical Composition ◽  
Raw Material ◽  
Element Analysis ◽  
X Ray ◽  
Dominant Component ◽  
Clay Deposits ◽  
Dammed Lake

AbstractVarved clay deposits from ice-dammed lakes are a particularly important and broadly applied raw material used for the production of high-quality ceramics (red bricks, roof tiles, etc.), but the mineralogy and geochemistry of these sediments are not fully understood. The aim of the present study was to determine the chemical and mineralogical composition of ice-dammed lake sediments of the Lębork deposit. Major-element analysis of the compositions of selected samples from the ice-dammed lake clays was performed by X-ray fluorescence (XRF) and trace elements were determined by inductively coupled plasma-mass spectrometry. The mineralogical composition of clay samples was determined by X-ray diffraction (XRD). Analyses of the chemical composition of the ice-dammed lake clays of the Lębork deposit showed that the dominant component was SiO2 with a mean content of 56.13 wt.%; the second most abundant component was Al2O3, with a mean content for the entire deposit of 11.61 wt.%. Analysis by ICP-MS indicated the presence of rare earth elements (REE), e.g. cerium, neodymium, lanthanum, and praseodymium; their mean contents are: 56.9, 27.0, 26.3, and 7.3 ppm, respectively. Mineralogical analysis of the varved clays identified quartz, muscovite, calcite, and clay minerals – illite, kaolinite, and montmorillonite. The material filling the Lębork basin is characterized by small lateral and vertical variability in chemical composition. The results of the present study may be of considerable importance in determining the parent igneous, metamorphic, and sedimentary rocks, the weathering products of which supplied material to the ice-dammed lake, as well as in determining the mechanisms and character of the sedimentation process itself.

Optimisation of Springback Predicted by Experimental and Numerical Approach by Using Response Surface Methodology

2005 ◽  
Vol 6-8 ◽  
pp. 753-762
Author(s):  
R. Bahloul ◽  
Phillippe dal Santo ◽  
Ali Mkaddem ◽  
A. Potiron
Keyword(s):  
Response Surface ◽  
Sheet Metal ◽  
Design Method ◽  
Fem Simulation ◽  
Numerical Approach ◽  
Tool Geometry ◽  
Nose Radius ◽  
Element Analysis ◽  
Metal Parts ◽  
Sheet Metal Parts

Bending has significant importance in the sheet metal product industry. Moreover, the springback of sheet metal should be taken into consideration in order to produce bent sheet metal parts within acceptable tolerance limits and to solve geometrical variation for the control of manufacturing process. Nowadays, the importance of this problem increases because of the use of sheet-metal parts with high mechanical characteristics (High Strength Low Alloy steel). This work describes robust methods of predicting springback of parts in 3D modelling subjected to bending and unbending deformations. Also the effects of tool geometry in the final shape after springback are discussed. The first part of this paper presents the laboratory experiments in wiping die bending, in which the influence of process variables, such as die shoulder radius, punch-die clearance, punch nose radius and materials properties were discussed. The second part summarises the finite element analysis by using ABAQUS software and compares these results with some experimental data. It appeared that the final results of the FEM simulation are in good agreement with the experimental ones. An optimisation methodology based on the use of experimental design method and response surface technique is proposed in the third part of this paper. That makes it possible to obtain the optimum values of clearance between the punch and the die and the optimum die radius which can reduce the springback without cracking and damage of product.

ELEMENT ANALYSIS OF JAPANESE PAPER BY PIXE

1999 ◽  
Vol 09 (03n04) ◽  
pp. 475-479
Author(s):  
TATSUYA SUZUKI
Keyword(s):  
Raw Material ◽  
Element Analysis ◽  
Japanese Paper

The Japanese papers, "washi", are made from the plants. Since the elements included in the washi have the informations of the raw material plants, there is potentiality of the identification of the production place by the element analysis of the washi. Three kinds of washi made of kozo, which have different habitats, were prepared. The elements in their washi were measured by the PIXE. It was confirmed that the amount of elements included in the washi depend on the habitats of their raw material plants.

A comprehensive survey on the occurrence of mycotoxins in maize dried distillers' grain and solubles sourced worldwide

2012 ◽  
Vol 5 (1) ◽  
pp. 83-88 ◽  
Author(s):  
I. Rodrigues ◽  
L. Chin
Keyword(s):  
Limit Of Detection ◽  
Raw Material ◽  
Alternative Ingredients ◽  
Comprehensive Survey ◽  
Negative Impacts ◽  
Contamination Levels ◽  
Distillers Grain ◽  
Aflatoxin B ◽  
Dried Distillers Grain ◽  
By Products

As cereal and protein sources suffer a price increase worldwide, the use of alternative ingredients in feeds has become increasingly appealing to the animal industry. Dried distillers' grain and solubles (DDGS) have been one of the ingredients which demand has dramatically increased over the last few years. In fact, the supply of maize DDGS is expected to increase to about 38.6 mmt by 2019-2020. The presence of mycotoxins in these by-products has been a matter of concern raised by their ubiquitous use. A rule of thumb typically used in the field is that the concentration of mycotoxins in the final by-product is about three times higher than that of the original raw material, which may be scientifically backed up by the fact that the remaining portions within the by-product are those which had a higher concentration of mycotoxins (outer portions of the grain). This paper is the outcome of a five-year study during which a total of 409 maize DDGS samples sourced worldwide were analysed for the mycotoxins of major importance which cause the great negative impacts in animal performance and health: aflatoxins (a sum of aflatoxin B1, B2, G1, G2), zearalenone, deoxynivalenol, a sum fumonisins B1 and B2 and ochratoxin A. From the total of samples tested, only 2% of the analysed DDGS showed contamination levels below the limit of detection (negative samples). 6% of samples had the presence of 1 mycotoxin only and the majority (92% of the samples) was contaminated with 2 or more mycotoxins.

scholarly journals Hybrid Analytical and Numerical Approach for Modeling Fluid Flow in Simplified Three-Dimensional Fracture Networks

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
D. Roubinet ◽  
S. Demirel ◽  
E. B. Voytek ◽  
X. Wang ◽  
J. Irving
Keyword(s):  
Fluid Flow ◽  
Three Dimensional ◽  
Fracture Network ◽  
Numerical Approach ◽  
Fracture Networks ◽  
Surrounding Matrix ◽  
Mesh Free ◽  
Fracture Scale ◽  
The Impact ◽  
Numerical Approaches

Modeling fluid flow in three-dimensional fracture networks is required in a wide variety of applications related to fractured rocks. Numerical approaches developed for this purpose rely on either simplified representations of the physics of the considered problem using mesh-free methods at the fracture scale or complex meshing of the studied systems resulting in considerable computational costs. Here, we derive an alternative approach that does not rely on a full meshing of the fracture network yet maintains an accurate representation of the modeled physical processes. This is done by considering simplified fracture networks in which the fractures are represented as rectangles that are divided into rectangular subfractures such that the fracture intersections are defined on the borders of these subfractures. Two-dimensional analytical solutions for the Darcy-scale flow problem are utilized at the subfracture scale and coupled at the fracture-network scale through discretization nodes located on the subfracture borders. We investigate the impact of parameters related to the location and number of the discretization nodes on the results obtained, and we compare our results with those calculated using reference solutions, which are an analytical solution for simple configurations and a standard finite-element modeling approach for complex configurations. This work represents a first step towards the development of 3D hybrid analytical and numerical approaches where the impact of the surrounding matrix will be eventually considered.

Finite element analysis of gradient lattice structure patterns for bone implant design

2020 ◽  
Vol 11 (4) ◽  
pp. 535-545
Author(s):  
Asliah Seharing ◽  
Abdul Hadi Azman ◽  
Shahrum Abdullah
Keyword(s):  
Finite Element Analysis ◽  
Relative Density ◽  
Mechanical Behaviour ◽  
Lattice Structure ◽  
Lattice Structures ◽  
Element Analysis ◽  
Bone Implant ◽  
Content Type ◽  
Octet Truss ◽  
Structure Patterns

PurposeThe objective of this paper is to identify suitable lattice structure patterns for the design of porous bone implants manufactured using additive manufacturing.Design/methodology/approachThe study serves to compare and analyse the mechanical behaviours between cubic and octet-truss gradient lattice structures. The method used was uniaxial compression simulations using finite element analysis to identify the translational displacements.FindingsFrom the simulation results, in comparison to the cubic lattice structure, the octet-truss lattice structure showed a significant difference in mechanical behaviour. In the same design space, the translational displacement for both lattice structures increased as the relative density decreased. Apart from the relative density, the microarchitecture of the lattice structure also influenced the mechanical behaviour of the gradient lattice structure.Research limitations/implicationsGradient lattice structures are suitable for bone implant applications because of the variation of pore sizes that mimic the natural bone structures. The complex geometry that gradient lattice structures possess can be manufactured using additive manufacturing technology.Originality/valueThe results demonstrated that the cubic gradient lattice structure has the best mechanical behaviour for bone implants with appropriate relative density and pore size.

Design and Analysis of an Example Lathe Spindle

2014 ◽  
Author(s):  
Rupal Vyasa ◽  
Raghu Echempati
Keyword(s):  
Real Life ◽  
Specific Topic ◽  
Element Analysis ◽  
Computational Tools ◽  
Modeling And Analysis ◽  
Iterative Design ◽  
Beam Elements ◽  
Medium Speed ◽  
Course Material ◽  
Good Learning

This paper discusses the modeling and analysis of an example medium speed medium precision lathe spindle. This and few other similar topics have been assigned as term projects in an introductory senior undergraduate/graduate level finite element analysis course taught at Kettering University. The experiences and the general feedback from the students of the class show satisfactory organization of the course material that includes modeling and analysis of real life examples. With reference to the specific topic on design of machine tool spindles, it is not a new area, however, it is generally taught at the graduate and research levels. Use of modern computational tools to perform iterative design and analysis calculations of such spindles make the senior undergraduate and/or graduate master students aware of the implications of modeling a real life system using the 1D and 3D finite beam elements and to validate those results by a CAE tool. Final course projects such as this serve as a good learning tool to the graduating engineers. Sample results obtained from various CAE tools such as UG-NX 7.5 are presented in the paper and discussed.

Simulation of the Heat-Insulating Sludge Waste Rubber Composite Brick by the Finite Element Method (FEM)

2018 ◽  
Vol 280 ◽  
pp. 451-461
Author(s):  
Weerapol Namboonruang ◽  
Nutthanan Suphadon
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Finite Element ◽  
Economic Factor ◽  
Raw Material ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Good Correspondence ◽  
Sludge Waste ◽  
Element Method

Recently, materials used to construct house or building wall are considered not only in the physical material behaviour but also energy conscious and economic factor. The possibility of utilization of the sludge waste obtained from the natural rubber manufacturing process as a raw material for producing composite brick was investigated. It has been widely known that the finite element method (FEM) is a tool used for finding accurate solutions of the heat transfer equation of materials including the composite bricks. In this work, study of the heat transfer of a composite brick containing rubber sludge waste (RSW) was showed and compared to results of finite element analysis (FEA) simulation. To determine the effect of rubber sludge waste to the heat transfer behaviour of composite brick with different volume fractions are varied by 10, 20, 30, 40 and 50%. It appeared that a FEA prediction showed good correspondence with the experimental results.

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