scholarly journals Finite Element Modeling of Multiscale Diffusion in Intercalated Nanocomposites

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Antonio Greco ◽  
Alfonso Maffezzoli
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Finite Element Modeling ◽  
Random Distribution ◽  
Geometric Model ◽  
Fe Analysis ◽  
Morphological Features ◽  
Diffusion Behavior ◽  
Simulation Results ◽  
Diffusion Simulation

This work is aimed to study the diffusion in 3D nanocomposites obtained with stacks of lamellar nanofillers characterized by the presence of permeable galleries, by finite element (FE) analysis. To this purpose, a geometric model, based on a random distribution of noninterpenetrating stacks, with each one being made of regularly spaced lamellae, was developed. The developed model is able to account for diffusion between stacks (interstack diffusion) as well as diffusion inside stacks (intrastack diffusion). Simulation results showed that intrastack diffusion, related to flow inside galleries, can be quite relevant, particularly at high values of gallery thickness. Comparison of the simulation results with literature models shows that when intrastack diffusion is not taken into account, the diffusion behavior in intercalated nanocomposites is not well predicted. Therefore, intrastack permeability of nanofillers such as organic modified clays cannot be neglected. Such intrastack diffusivity is shown to depend on the morphological features of the nanofiller requiring the development of a proper mathematical model.

scholarly journals Developing an Extended IFC Data Schema and Mesh Generation Framework for Finite Element Modeling

2019 ◽  
Vol 2019 ◽  
pp. 1-19
Author(s):  
Zhao Xu ◽  
Zezhi Rao ◽  
Vincent J. L. Gan ◽  
Youliang Ding ◽  
Chunfeng Wan ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Modeling ◽  
Mesh Generation ◽  
Geometric Model ◽  
Information Modeling ◽  
Element Analysis ◽  
Element Modeling ◽  
The Finite Element Analysis ◽  
Ifc Standard

Mesh generation plays an important role in determining the result quality of finite element modeling and structural analysis. Building information modeling provides the geometry and semantic information of a building, which can be utilized to support an efficient mesh generation. In this paper, a method based on BRep entity transformation is proposed to realize the finite element analysis using the geometric model in the IFC standard. The h-p version of the finite element analysis method can effectively deal with the refined expression of the model of bending complex components. By meshing the connection model, it is suggested to adopt the method of scanning to generate hexahedron, which improves the geometric adaptability of the mesh model and the quality and efficiency of mesh generation. Based on the extension and expression of IFC information, the effective finite element structure information is extracted and extended into the IFC standard mode. The information is analyzed, and finally the visualization of finite element analysis in the building model can be realized.

scholarly journals Mathematical model of acoustic characteristics of polyurethane foam used for sound absorption in aerospace engineering

2021 ◽  
Vol 20 (2) ◽  
pp. 53-62
Author(s):  
A. V. Kuznetsov ◽  
A. A. Igolkin ◽  
A. I. Safin ◽  
A. O. Pantyushin
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Absorption Coefficient ◽  
Finite Element Modeling ◽  
Sound Absorption ◽  
Sound Absorption Coefficient ◽  
Sound Insulation ◽  
Space Technology ◽  
Acoustic Characteristics ◽  
Element Modeling

When solving the problem of reducing the acoustic load on the spacecraft during the launch and flight of the launch vehicle, finite element modeling of acoustic processes under the nose fairing is carried out. To successfully solve this problem, a mathematical model of the acoustic characteristics of the material used for sound insulation is required. The existing mathematical models of the acoustic characteristics of materials are not suitable for the material under consideration that can be used in rocket and space technology to increase the sound insulation of the payload fairing + transfer compartment assembly. To obtain the sound absorption coefficient of the material, an impedance tube measurement method with two microphones is used. Using the method of differential evolution, the coefficients of a mathematical model of acoustic characteristics of the Delany-Bazley type for the specified material are selected. The sound absorption coefficient obtained experimentally and that calculated using the obtained model are compared; the average and maximum values of the error are shown. The resulting model will make it possible to carry out finite element modeling of acoustic and vibroacoustic processes under the nose fairing, taking into account the location of the sound-absorbing material.

Application of the collision mathematical model based on a BP neural network in railway vehicles

2020 ◽  
pp. 095440972095986
Author(s):  
Yu-Ru Li ◽  
Tao Zhu ◽  
Shou-Ne Xiao ◽  
Bing Yang ◽  
Guang-Wu Yang ◽  
...  
Keyword(s):  
Neural Network ◽  
Mathematical Model ◽  
Finite Element ◽  
Bp Neural Network ◽  
Learning Performance ◽  
Small Data ◽  
Data Set ◽  
Computation Efficiency ◽  
Simulation Results ◽  
Relative Errors

In order to enhance the learning performance of small-data-set models and improve the computation efficiency of finite element simulations of vehicle collision, the collision mathematical model (VCMM) based on the back-propagation (BP) neural network is established to predict the collision response data of a single car and marshalling cars at unknown velocities. The predicted results of VCMM were compared with the simulation results of the finite element method (FEM) to verify the model. The compared results show that the maximum relative errors of deformation, energy absorption and average interfacial force of a single vehicle are all below 8.5%, and the relative errors of the maximum compression of the C0 coupler and the internal energy of the A1 car among the marshalling cars are all less than 5%. In addition, the calculation time of the single car and marshalling cars collisions based on the VCMM are reduced by 24.36 and 61.8 times, respectively, compared with the FEM results, and the simulation calculation efficiency is greatly improved. The prediction result of VCMM will partially replace experimental and simulation results for crashworthiness and safety design of the vehicle structure in future studies.

Finite Element Analysis of Compressive Strength of Recycled Coarse Aggregate-Filled Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 331-334
Author(s):  
Jing Li ◽  
Zhen Liu ◽  
Xian Feng Qu ◽  
Chong Qiang Zhu ◽  
Yuan Zhang
Keyword(s):  
Finite Element ◽  
Compressive Strength ◽  
Mechanical Model ◽  
Coarse Aggregate ◽  
Geometric Model ◽  
Element Analysis ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates ◽  
Concrete Blocks ◽  
Simulation Results

In order to study prism compressive strength of recycled coarse aggregates-filled concrete, recycled coarse aggregates of particle size for 40-80mm were made from abandoned brick and concrete blocks. 4 groups of recycled coarse aggregates-filled concrete prism objects were made, and the compressive strength of the specimens were done. Using the finite element analytical software(ANSYS) , the stress nephogram and fractured condition of recycled coarse aggregate-filled concrete were obtained after the establishment of the geometric model, calculational model and mechanical model. The results showed that numerical simulation results were good agree with the actual experimental results.

Finite Element Modeling of Cutting Force and Chip Formation During Thermally Assisted Machining of Ti6Al4V Alloy

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Yao Xi ◽  
Michael Bermingham ◽  
Gui Wang ◽  
Matthew Dargusch
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Cutting Force ◽  
Formation Process ◽  
Chip Formation ◽  
Cutting Forces ◽  
Experimental Results ◽  
Strongly Correlated ◽  
Element Modeling ◽  
Simulation Results

The improvement in machinability during thermally assisted turning of the Ti-6Al-4V alloy has been investigated using finite element modeling. A 2D thermally assisted turning model was developed and validated by comparing the simulation results with experimental results. The effect of workpiece temperature on the cutting force and chip formation process was examined. The predicted cutting forces and chip morphologies from the simulation strongly correlated with the experimental results. It was observed from the simulation that the chip forms after the coalescence of two deformed regions in the shear band and that the cyclic cutting forces are strongly related to this chip formation process.

scholarly journals Numerical Study of Being Forced Leather Cap Type Pig in Straight Gas Pipeline

2016 ◽  
Vol 10 (1) ◽  
pp. 141-148
Author(s):  
Liqiong Chen ◽  
Yunyun Li ◽  
Xiaoxiao Chen ◽  
Yilan Zhan ◽  
Meijuan Dang
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Numerical Study ◽  
Geometric Model ◽  
Gas Pipeline ◽  
Average Force ◽  
Oil Pipeline ◽  
Finite Element Software ◽  
Operation Rules ◽  
The Mathematical Model

The research on pipeline pigging technology is significant for the operation and management of pipeline. Domestic and foreign scholars usually research the operation rules of pigging in oil pipeline. There are few studies about gas pipeline pigging running because of running rate. The author established the force calculating model and corresponding numerical methods of leather cap type pig in gas pipeline. The model is based on geometric model of oil pipeline pigging. Combining pigging operation parameters with records in September 2013 and February 2014 at Bei Neihuan, the thesis used mathematical method and finite element software respectively to verify the mathematical model. The mathematical results described the average force of cup. The results indicated that the reason of the breaking of the cup is the force, instead of the cup material, temperament extrinsic reasons, etc. The force is larger than the tensile strength of the cup. The results of ANSYS finite element software simulation described the force of different parts of the cup. It is found that the force exceeding of the cup anti-pull force strength in the upper and lower sides of the cup is larger. Both results showed that using the mathematical model can quickly calculate cup pigging force conditions and determine the cause of damage to the cup. It can improve the efficiency of pigging.

Dynamic States Specific Analysis for Belt Conveyor Based on FDM

2013 ◽  
Vol 278-280 ◽  
pp. 27-30
Author(s):  
Xiao Shen ◽  
Qun Wang ◽  
Zhou Yu Fu ◽  
Shuo Wei Bai ◽  
Zhao Yang Sun
Keyword(s):  
Mathematical Model ◽  
Finite Element Method ◽  
Mathematical Method ◽  
Finite Element ◽  
Continuous Model ◽  
Belt Conveyor ◽  
Specific Analysis ◽  
Simulation Results ◽  
The Mathematical Model ◽  
Dynamic States

There are two common research methods on the dynamic states model of belt conveyor in China at present. The mathematical model is built by finite element method then it is solved by numerical method. And the continuous model is built when the belt is treated as elastic body then it is solved by mathematical method. This paper puts forward the establishment of continuous model, the model is solved by FDM and the simulation results are given.

Multiscale Model of Shape Rolling Taking into Account the Microstructure Evolution – Finite Element Modeling

2014 ◽  
Vol 1025-1026 ◽  
pp. 379-384 ◽  
Author(s):  
Łukasz Łach ◽  
Dmytro Svyetlichnyy
Keyword(s):  
Finite Element ◽  
Cellular Automata ◽  
Finite Element Modeling ◽  
Strain Rate ◽  
Microstructure Evolution ◽  
Multiscale Model ◽  
Rolling Process ◽  
Shape Rolling ◽  
Element Modeling ◽  
Simulation Results

The use of appropriate forming processes allows to obtain materials of required quality, which are fulfill different technological criteria. The basic type of properties, which are fundamental for material use in specific operating conditions, are mechanical ones. They directly depend on the microstructure. Model of microstructure evolution allows for multi-criteria optimization of technological processes in view of final product properties, taking into account technological conditions. The objective of this study is development a multiscale model of microstructure evolution during the shape rolling process and presentation the finite element modeling results for 5 mm round bars rolled in diamond, oval and round grooves. The model allows to obtain parameters of technological process (by means of finite element model - FEM) and microstructural parameters (with use cellular automata - CA). FEM is used for design and selection of the grooves on the first stage [1] and for the simulations of shape rolling process in macro scale on the second stage. The next stage includes the use of FEM modeling results for simulation of microstructure evolution by cellular automata. The article presents the simulation results of shape rolling (5 mm round bars in diamond - oval scheme) with used the finite element method. This stage is the second one in the calculation sequence of the developed multiscale model. The basic process parameters such as temperature, components of strain and strain rate tensors and strain rate intensity at arbitrary points of deformed material are the modeling results. Selected FEM simulation results are presented in the article.

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