Influence of Nano Materials in the Distressed Domain during Maintenance

2015 ◽  
Vol 1086 ◽  
pp. 132-136
Author(s):  
J. Nirmala ◽  
G. Dhanalakshmi ◽  
A. Rajaraman
Keyword(s):  
Finite Element ◽  
Rectangular Domain ◽  
The Body ◽  
Nano Materials ◽  
Test Results ◽  
Partial Differential ◽  
Seepage Analysis ◽  
Mixed Mortar ◽  
Two Space Dimensions ◽  
Flow Through

In irrigation structures, seepage through the body wall and foundation play a major role for the assessment of failures in the structures. To design any kind of structure for the proper irrigation, the effect due to seepage should be considered widely. Many methods have been suggested for the prediction of seepage. Seepage analysis ofirrigation structures works mainly on the basis of two dimensional Laplace equation. The Partial Differential Equation Toolbox in MATLAB provides a powerful and flexible environment for the study and solution of partial differential equations in two space dimensions and time. The equations are discretized by the Finite Element Method (FEM). Fluid flow through porous media particularly in the case of irrigation and hydraulic structures like dams and weirs is the focus of the current study and here flaws or cracks which occur in the domain cause variations and need remedial ones to improve or bring back to the original flow pattern. Since flaws in terms of fissures are very small injecting nanomaterial mixed mortar can provide significant improvements and modifications. Here in a rectangular domain the flow is studied throw finite element modeling with and without different sizes and location of flaws. Later these flaws are filled with nanomaterial mortars whose properties are based on test results and the flow is again studied to bring out the changes and improvements. Results are given for different nanomaterial mortars with different flaw sizes.

Adaptive Finite Element Method for Solving Poisson Partial Differential Equation

2021 ◽  
Vol 4 (1) ◽  
pp. 1-18
Author(s):  
Gokul KC ◽  
Ram Prasad Dulal
Keyword(s):  
Differential Equation ◽  
Finite Element Method ◽  
Partial Differential Equation ◽  
Finite Element ◽  
Poisson Equation ◽  
Rectangular Domain ◽  
Adaptive Finite Element Method ◽  
Adaptive Finite Element ◽  
Partial Differential ◽  
Element Method

Poisson equation is an elliptic partial differential equation, a generalization of Laplace equation. Finite element method is a widely used method for numerically solving partial differential equations. Adaptive finite element method distributes more mesh nodes around the area where singularity of the solution happens. In this paper, Poisson equation is solved using finite element method in a rectangular domain with Dirichlet and Neumann boundary conditions. Posteriori error analysis is used to mark the refinement area of the mesh. Dorfler adaptive algorithm is used to refine the marked mesh. The obtained results are compared with exact solutions and displayed graphically.

Modelling of the Behaviour of Dynamical Gas Seals: Calculation with a Finite Element Method Implicitly Assuring the Continuity of Flow

1995 ◽  
Vol 209 (3) ◽  
pp. 195-201 ◽  
Author(s):  
P Hernandez ◽  
R Boudet
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Results ◽  
The Body ◽  
Dynamical Model ◽  
The Finite Element Method ◽  
Flow Through ◽  
Gas Seals ◽  
Stiffness And Damping ◽  
Element Method

The objective of this paper is to present a model of the behaviour of dynamical seals and the corresponding numerical results. These seals are used in the mechanism to realize partial sealing when the relative rotating speeds are too high for usual solutions. The studied seals mainly include two discs: one is attached to the shaft and the other to the body, the last one being pushed and the first being attached by springs. During operation, a gaseous film is created between the discs, preventing any contact. The control of the film thickness allows the leakage flow to be controlled. For the behaviour of such mechanisms, an analytical formulation of the problem is firstly presented. Then a geometrical and kinematical model having one degree of freedom is proposed to model the mechanism having two discs in relative rotation, one of which is spirally grooved. A dynamical model associated with the motion of the disc attached to the body has been developed and the mechanics of thin viscous films is used to study the behaviour of the gaseous film at the interface. Utilization of the finite element method in the mechanics of thin viscous films is introduced and a description of the elements used is presented. The influence of the groove's angle and the groove's depth is shown through numerical results concerning leakage mass flow through the mechanism and the loading capacity of the fluid film, as well as the coefficients of stiffness and damping associated with the dynamical model.

scholarly journals Update on Alternative Occupant Volume Testing

2010 ◽  
Author(s):  
Michael Carolan ◽  
Michelle Priante Muhlanger
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
The Body ◽  
Original Structure ◽  
Test Results ◽  
Compression Tests ◽  
Load Path ◽  
Test Procedures ◽  
Loading Test ◽  
Static Compression

This paper describes the conduct of the first of a series of quasi-static compression tests of rail passenger equipment being done to examine occupant volume strength. Specifically, this program is investigating methods of evaluating occupant volume integrity when loads are placed along the collision load path of the occupant volume. Budd Pioneer car 244 has been chosen as the test article to examine alternative occupant volume loading strategies. Since this car has been involved in several impact tests as part of a previous research program, it is important to verify the structural integrity of the vehicle before conducting an alternative loading test. Although the vehicle has been modified with crash energy management crush zones at both ends, the occupant volume between the body bolsters is unmodified from the original structure. The 800,000-pound compressive strength test will be used to ensure the structural integrity of the car is intact. Before the conduct of this test, repairs were made to the crush zone. These repairs included replacement of trigger elements in the form of shear bolts and shear rivets. Additionally, energy absorbing elements were removed from the pushback coupler and primary energy absorbers because they would not contribute to the load path of this test. Steel blocks were added to the sliding sill element, enabling it to contact the fixed sill and enhancing the load-bearing capacity of the sliding-fixed sill connection. Preliminary results of this test include an overall description of the test procedures, discussion of permanent deformation observed during the test, and presentation of finite-element simulation results. Detailed analysis of test results, including strain gage data, is ongoing. The test results are being compared with the finite-element model results in support of the next tests planned for this series. The next two tests will evaluate the carbody when it is loaded along its collision load path to establish the elastic limit and crippling strength.

PENGEMBANGAN BAHAN AJAR IPA SMP PADA TEMA ENERGI DALAM TUBUH MENGGUNAKAN METODE 4STMD

EDUSAINS ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 166-175
Author(s):  
Gia Juniar Nur Wahidah ◽  
Sjaeful Anwar
Keyword(s):  
Concept Maps ◽  
The Body ◽  
Instructional Materials ◽  
Teaching Material ◽  
Test Results ◽  
Teaching Materials ◽  
Eligibility Criteria ◽  
Material Development ◽  
Selection Step ◽  
Selection Of

Abstract This research aims to produce science teaching materials in junior level with Energy in The Body as the theme using Four Steps Teaching Material Development  (4STMD). The material is presented in an integrated way so that students can  think holistically and contextually. The method used in this study is Research and Development. In this R&D methods is used 4STMD. There are four steps done on the development of teaching materials, the selection step, structuring step, characterization, and didactic reduction. Selection step includes the selection of indicators in accordance with the demands of the curriculum which is then developed with the selection of concepts and values that are integrated with the concept of science. Structuring step includes make macro structures, concept maps, and multiple representations. Characterization's step includes preparation instruments, then  trial to students to identify difficult concepts. The last, didactic reduction was done by neglect and the annotations in the form of sketches.The test results readability aspect instructional materials lead to the conclusion that by determining the main idea, the legibility of teaching materials reached 67%, with moderate readability criteria. Test results of feasibility aspects based on the results of questionnaires to the 11 teachers lead to the conclusion that the overall, level of eligibility teaching materials reached 91% with the eligibility criteria well. Keywords: teaching materials; energy; 4STMD Abstrak Penelitian ini bertujuan untuk menghasilkan bahan ajar IPA SMP pada tema Energi dalam Tubuh menggunakan metode Four Steps Teaching Material Development (4STMD). Materi disajikan secara terpadu sehingga memacu siswa untuk berpikir secara holistik dan kontekstual. Metode penelitian yang digunakan pada penelitian ini adalah metode penelitian dan pengembangan. Dalam penelitian dan pengembangan yang ini, digunakan metode Four Steps Teaching Material Development (4STMD). Terdapat empat tahap yang dilakukan pada pengembangan bahan ajar, yakni tahap seleksi, strukturisasi, karakterisasi, dan reduksi didaktik. Tahap seleksi meliputi pemilihan indikator yang sesuai dengan tuntutan kurikulum yang kemudian dikembangkan dengan pemilihan konsep dan nilai yang diintegrasikan dengan konsep IPA. Tahap strukturisasi meliputi pembuatan struktur makro, peta konsep, dan multipel representasi dari materi. Tahap karakterisasi meliputi penyusunan instrumen karakterisasi, kemudian uji coba kepada siswa untuk mengidentifikasi konsep sulit. Tahap terakhir, yaitu reduksi didaktik konsep terhadap konsep sulit. Reduksi didaktik yang dilakukan berupa pengabaian dan penggunaan penjelasan berupa sketsa. Hasil uji aspek keterbacaan bahan ajar menghasilkan kesimpulan bahwa berdasarkan penentuan ide pokok, keterbacaan bahan ajar mencapai 67%, dengan kriteria keterbacaan tinggi. Hasil uji aspek kelayakan berdasarkan hasil angket terhadap 11 orang guru menghasilkan kesimpulan bahwa secara keseluruhan tingkat kelayakan bahan ajar mencapai 91% dengan kriteria kelayakan baik sekali. Kata Kunci: bahan ajar; energi; 4STMD  Permalink/DOI: http://dx.doi.org/10.15408/es.v8i2.2039  

Prediction of Tread Pattern Wear by an Explicit Finite Element Model3

2007 ◽  
Vol 35 (4) ◽  
pp. 276-299 ◽  
Author(s):  
J. C. Cho ◽  
B. C. Jung
Keyword(s):  
Finite Element ◽  
Wear Rate ◽  
Tangential Stress ◽  
Rate Equation ◽  
Constitutive Equations ◽  
Slip Velocity ◽  
Test Results ◽  
Explicit Finite Element ◽  
Driving Condition ◽  
Driving Conditions

Abstract Tread pattern wear is predicted by using an explicit finite element model (FEM) and compared with the indoor drum test results under a set of actual driving conditions. One pattern is used to determine the wear rate equation, which is composed of slip velocity and tangential stress under a single driving condition. Two other patterns with the same size (225/45ZR17) and profile are used to be simulated and compared with the indoor wear test results under the actual driving conditions. As a study on the rubber wear rate equation, trial wear rates are assumed by several constitutive equations and each trial wear rate is integrated along time to yield the total accumulated wear under a selected single cornering condition. The trial constitutive equations are defined by independently varying each exponent of slip velocity and tangential stress. The integrated results are compared with the indoor test results, and the best matching constitutive equation for wear is selected for the following wear simulation of two other patterns under actual driving conditions. Tens of thousands of driving conditions of a tire are categorized into a small number of simplified conditions by a suggested simplification procedure which considers the driving condition frequency and weighting function. Both of these simplified conditions and the original actual conditions are tested on the indoor drum test machines. The two results can be regarded to be in good agreement if the deviation that exists in the data is mainly due to the difference in the test velocity. Therefore, the simplification procedure is justified. By applying the selected wear rate equation and the simplified driving conditions to the explicit FEM simulation, the simulated wear results for the two patterns show good match with the actual indoor wear results.

MGP NAPL interception with organophyllic media: flow-through column test results

2006 ◽  
Vol 14 (2) ◽  
pp. 489-493
Author(s):  
Michael J. Gefell ◽  
Erin C. Rankin ◽  
William R. Jones
Keyword(s):  
Test Results ◽  
Column Test ◽  
Flow Through

scholarly journals Theoretical analysis and experimental research on multi-layer elastic damping track structure

2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199497
Author(s):  
Guanghui Xu ◽  
Shengkai Su ◽  
Anbin Wang ◽  
Ruolin Hu
Keyword(s):  
Finite Element ◽  
Analytical Solution ◽  
Finite Element Simulation ◽  
Reaction Force ◽  
Vibration Reduction ◽  
Vertical Direction ◽  
Propagation Path ◽  
Track Structure ◽  
Test Results ◽  
Element Simulation

The increase of axle load and train speed would cause intense wheelrail interactions, and lead to potential vibration related problems in train operation. For the low-frequency vibration reduction of a track system, a multi-layer track structure was proposed and analyzed theoretically and experimentally. Firstly, the analytical solution was derived theoretically, and followed by a parametric analysis to verify the vibration reduction performance. Then, a finite element simulation is carried out to highlight the influence of the tuned slab damper. Finally, the vibration and noise tests are performed to verify the results of the analytical solution and finite element simulation. As the finite element simulation indicates, after installation of the tuned slab damper, the peak reaction force of the foundation can be reduced by 60%, and the peak value of the vertical vibration acceleration would decrease by 50%. The vibration test results show that the insertion losses for the total vibration levels are 13.3 dB in the vertical direction and 21.7 dB in the transverse direction. The noise test results show that the data of each measurement point is smoother and smaller, and the noise in the generating position and propagation path can be reduced by 1.9 dB–5.5 dB.

Sign in / Sign up

Export Citation Format

Share Document