scholarly journals Design optimization of the satellite in precessional transmission

2018 ◽  
Vol 178 ◽  
pp. 05008
Author(s):  
Stanislav Lealin
Keyword(s):  
Noise Reduction ◽  
Load Capacity ◽  
Elastic Compliance ◽  
Complex Structures ◽  
The Finite Element Method ◽  
Linear Deformation ◽  
Satellite Design ◽  
Deformation Simulation ◽  
Contact Loads ◽  
Radial Channel

One of the important tasks in the design of gears and gearboxes based on them is to increase the load capacity, durability and noise reduction with moderate requirements for manufacturing precision by providing elastic compliance of the teeth with simple satellite manufacturing technology. In the paper is firstly presented a base satellite in a precessional transmission. The design is rigid and non-technological. There was simulated the workload and the results are presented as a linear deformation. Simulation was based on the special module for the calculation and analysis of complex structures using the integrated module Stress Analysis (program Autodesk Inventor Professional 2012). It uses the finite element method calculation, based on the ANSYS program. Then is shown an optimized satellite structure. This option provides an increased durability and noise reduction due to local and general tooth compliance. The main drawback of this satellite is the high laboriousness of making cut-outs in the satellite. In this satellite, by increasing the diameter of the radial channel, it is possible to reduce the wall thickness and thereby increase the compliance. The simulation results of a new satellite design are presented. Compliance increased roughly by 4 times compared to the base version. When the gear is in mesh with the satellite, due to the increased elastic compliance of the teeth, a multi-pairing mesh is achieved, which reduces the contact loads and noise, increases the service life of the transmission.

Reliability Indexes Calculation of Industrial Boilers Under Stochastic Thermal Process

1998 ◽  
Author(s):  
Olivier Rollot ◽  
Maurice Pendola ◽  
Maurice Lemaire ◽  
Igor Boutemy
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Methods ◽  
Thermal Process ◽  
Complex Structures ◽  
The Finite Element Method ◽  
Random Data ◽  
Electric Company ◽  
New Methods ◽  
Industrial Boilers

Abstract This text sums up a research for the French Electric Company, EDF, which wants to know the influence of the temperature variability on the reliability of some of their boilers. These boilers are very complex structures whose behavior has to be modelized by the Finite Element Method, FEM. This work is an application of Finite Element Methods in a reliability context, that means the introduction of random data into a classical FEM, in order to determine the reliability of the structures. These random data may concern geometry, material characteristics of the structures or the loads the structure may carry. Then, it’s necessary to employ new methods to take into account these stochastic approaches and to obtain more efficient decision’s elements for a better control of the boilers.

Reliability Comparison of Trusses Made of Thin-Walled Steel Sections

2018 ◽  
Vol 931 ◽  
pp. 280-287
Author(s):  
Sergey V. Skachkov ◽  
Ekaterina Y. Golotaystrova
Keyword(s):  
Load Capacity ◽  
Reliability Function ◽  
System Failure ◽  
Entire System ◽  
The Finite Element Method ◽  
Probabilistic Technique ◽  
Steel Sections ◽  
Internal Forces ◽  
Thin Walled ◽  
Rod Structures

The authors suggest a new truss with nodal conjugations without misalignment in the nodes. They have a greater load capacity and reliability. The results have been confirmed by the calculation of the above-mentioned trusses by the finite element method. The reliability function of trusses made of thin-walled steel sections can be determined taking into account the rods destruction probability in the system. We consider a design with the most unfavorable design model in which the destruction of any rod leads to the entire system failure. For the truss refusal it is assumed that the yield point of the material is reached at least in one of its cores. A probabilistic technique for estimating the reliability of rod structures made of thin-walled steel sections has been proposed. Other parameters being equal, including the geometric dimensions of the truss, loads, the nature of their application one can determine the most rational scheme of the truss in terms of its reliability. Differences in nodes design and internal forces direction will lead to a change in their values in trusses elements. Thus, the trusses reliability will depend on the mathematical expectation of internal efforts, camber and flexibility.

A New Method for Elastic-Plastic Contact Analysis of a Deformable Sphere and a Rigid Flat

2005 ◽  
Vol 128 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Li Po Lin ◽  
Jen Fin Lin
Keyword(s):  
New Method ◽  
Contact Load ◽  
Rigid Sphere ◽  
The Finite Element Method ◽  
Numerical Errors ◽  
Elastic Regime ◽  
Contact Loads ◽  
Indentation Tests ◽  
Metal Materials ◽  
Contact Parameters

A new method is developed in the present study to determine the elastoplastic regime of a spherical asperity in terms of the interference of two contact surfaces. This method provides an efficient way to solve the problem of discontinuities often present in the reported solutions for the contact load and area or the gradients of these parameters obtained at either the inception or the end of the elastoplastic regime. The well-established solutions for the elastic regime and experimental data of metal materials using indentation tests are provided as the references to determine the errors of these contact parameters due to the use of the finite-element method. These numerical errors provide the basis to adjust the contact area and contact load of a rigid sphere in contact with a flat such that the dimensionless mean contact pressure Pave∕Y (Y: the yielding strength) and the dimensionless contact load Fpc∕Fec (Fec, Fpc: the contact loads corresponding to the inceptions of the elastoplastic and fully plastic regimes, respectively) reaches the criteria arising at the inception of the fully plastic regime, which are available from the reports of the indentation tests for metal materials. These two criteria are however not suitable for the present case of a rigid flat in contact with a deformable sphere. In the case of a rigid flat in contact with a deformable sphere, the proportions in the adjustments of these contact parameters are given individually the same as those arising in the indentation case. The elastoplastic regime for each of these two contact mechanisms can thus be determined independently. By assuming that the proportion of adjustment in the elastoplastic regime is a linear function, the discontinuities appearing in these contact parameters are absent from the two ends of the elastoplastic regime in the present study. These results are presented and compared with the published results.

Performance Analysis of High Speed Floating Ring Hybrid Bearing in the Laminar and Turbulent Regimes

2011 ◽  
Vol 197-198 ◽  
pp. 1776-1780 ◽  
Author(s):  
Hong Guo ◽  
Bo Qian Xia ◽  
Shao Qi Cen
Keyword(s):  
Reynolds Number ◽  
Laminar Flow ◽  
Turbulent Flow ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Load Capacity ◽  
Flow Equation ◽  
The Finite Element Method ◽  
Static And Dynamic Characteristics ◽  
Hybrid Bearing

This paper presents a theoretical study concerning the static and dynamic characteristics of high speed journal floating ring hybrid bearing compensated by interior restrictor under laminar flow and turbulent flow respectively. The turbulent flow fluid film control equations and the pressure boundary conditions of this floating ring bearing together with the restrictor flow equation are solved by using the Finite Element Method. The variation regularity of static and dynamic characteristics such as load capacity, friction power loss, stiffness, damping etc. is analyzed. By comparing the laminar flow results and turbulent flow results, it is found that the characteristics coefficients are adjacent under small Reynolds number (laminar flow is dominant). But the characteristics coefficients are discrepant under big Reynolds number (turbulent flow is dominant). So turbulence lubrication theory is more accurate to high speed floating ring bearing.

Analysis of Aerodynamic Journal Bearings With Small Number of Herringbone Grooves by Finite Element Method

1994 ◽  
Vol 116 (4) ◽  
pp. 698-704 ◽  
Author(s):  
D. Bonneau ◽  
J. Absi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Study ◽  
Load Capacity ◽  
Journal Bearings ◽  
The Finite Element Method ◽  
Bearing Number ◽  
Comparison Of The Results ◽  
Herringbone Grooves ◽  
Element Method

A numerical study of gas herringbone grooved journal bearings is presented for small number of grooves. The compressible Reynolds equation is solved by use of the Finite Element Method. The nonlinearity of the discretized equations is treated with the Newton-Raphson procedure. A comparison of the results for a smooth bearing with previously published results is made and the domain of validity of the Narrow Groove Theory is analyzed. Load capacity, attitude angle, and stiffness coefficients are given for various configurations: groove angle and thickness of grooves, bearing number, and that for both smooth and grooved member rotating.

Elastic and Plastic Analysis of Drive Wheel’s Hertz Contact

2012 ◽  
Vol 184-185 ◽  
pp. 188-195
Author(s):  
Jun Jie Zhao ◽  
Hong Qi Tian ◽  
Yue Qing Ren ◽  
Zhai Jun Lu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Carrying Capacity ◽  
Rational Design ◽  
Load Capacity ◽  
Contact Theory ◽  
Line Contact ◽  
The Finite Element Method ◽  
Hertz Contact ◽  
Plastic Analysis

Conventional drive wheel strength check is based on Hertz line contact theory to do the calculation, for security reasons, the design is more conservative,so that there is a certain margin in carrying capacity of the wheel. To address the above issues, this paper analyzes the wheel contact problem for a precise non-linear contact by the finite element method. By comparison of two methods, it verifies that using the finite element is reasonable to deal with these issues, while it provides a reference for the rational design of full load capacity wheels as well.

scholarly journals Stress Analysis of IBS Molding Machine

2019 ◽  
Vol 8 (3) ◽  
pp. 2427-2431
Keyword(s):  
Finite Element ◽  
Static Pressure ◽  
Structural Strength ◽  
Residential Buildings ◽  
Load Capacity ◽  
The Finite Element Method ◽  
Molding Machine ◽  
Finite Element Software ◽  
Modern Methods ◽  
Machine Structure

Home is a place for shelter and survival for every living thing. These residential buildings are made using materials, one of which is brick. The technology of making bricks continues to grow over time. At present, bricks have been made using machines that use modern methods with the Interlocking Brick System (IBS) model. This molding machine using pneumatic to press the clay in the mold to becomes an IBS. This study aimed to determine the structural strength of the IBS printing press when given a load when printing is carried out. This research also serves to determine the most vulnerable locations on the machine structure as a concern when the load capacity will be increased. The analysis was carried out using the finite element method by using the finite element software. The simulation results obtained are, this IBS brick molding machine is safely operated for static pressure loads of 100 bar (10MPa).

scholarly journals NUMERICAL STUDY ON EFFECTS OF TENON SIZES ON WITHDRAWAL LOAD CAPACITY OF MORTISE AND TENON JOINT

Wood Research ◽  
2021 ◽  
Vol 66 (2) ◽  
pp. 321-330
Author(s):  
Tianxing Zhang ◽  
Wengang Hu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Response Surface ◽  
Numerical Study ◽  
Load Capacity ◽  
The Finite Element Method ◽  
Surface Method ◽  
Mortise And Tenon ◽  
Relationship Of ◽  
The Relationship

The effect of tenon length and tenon width on withdrawal load capacity of mortise and tenon (M-T) joint was studied based on the finite element method (FEM), and the relationship of withdrawal load capacity relating to tenon length and tenon width was regressed using response surface method. The results showed that the tenon length and tenon width had remarkable effects on withdrawal load capacity of M-T joint T-shaped sample. The effect of tenon length on withdrawal load capacity was greater than tenon width. The regression equation used to predict the withdrawal load capacity was capable of optimizing the tenon sizes of M-T joint with R-square of 0.926. Using FEM can get more knowledge of M-T joint visually, and reduce the costs of materials and time of experiments.

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