scholarly journals Local stresses in the keel when the ship is docked

2020 ◽  
pp. 28-31
Author(s):  
В.А. Манухин
Keyword(s):  
Spatial Modeling ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Simple Method ◽  
Total Strength ◽  
Local Stresses ◽  
Support Device ◽  
Bending Of Beams

При постановке судна в док на днищевые перекрытия со стороны килевой дорожки действуют значительные реактивные усилия, вызывающие местные деформации и напряжения в киле, стрингерах и флорах. С днищевых связей усилия передаются в основном на поперечные переборки и в меньшей степени на бортовые перекрытия, что вызывает общий изгиб корпуса судна. Расчеты общей прочности при постановке судов и кораблей в док показывают, что напряжения от общего изгиба корпуса незначительны. Дополнительные локальные напряжения от местного изгиба продольных днищевых связей, и в первую очередь в киле, при использовании балочных моделей либо не учитываются совсем, либо определяются достаточно условно. Альтернативой является использование метода конечных элементов (МКЭ) при достаточно подробном пространственном моделировании связей судна, дока и опорного устройства, что весьма затратно. В данной работе предлагается достаточно простая методика оценки локальных напряжений в киле при постановке судна в сухой док. Методика основана на использовании теории изгиба балок на сплошном упругом основании. Приводится пример расчета баржи-площадки. Показано, что напряжения в киле баржи вблизи поперечных переборок могут достигать недопустимо больших значений. Полученные результаты подтверждаются расчетом по МКЭ трехмерной модели баржи. When the ship is docked, significant reactive forces act on the bottom slabs from the keel track side, causing local deformations and stresses in the keel, stringers and floras. From the bottom braces, forces are transmitted mainly to the transverse bulkheads and, to a lesser extent, to the side floors, which causes a general bending of the ship's hull. Calculations of the total strength when ships and ships are docked show that the stresses from the general bending of the hull are insignificant. Additional local stresses from local bending of longitudinal bottom ties, and primarily in the keel, when using beam models, are either not taken into account at all, or are determined rather conditionally. An alternative is to use the finite element method (FEM) with a sufficiently detailed spatial modeling of the ship, dock and support device connections, which is very costly. This paper proposes a fairly simple method for assessing local stresses in the keel when the ship is in dry dock. The technique is based on the use of the theory of bending of beams on a solid elastic foundation. An example of calculation of the platform barge is given. It is shown that stresses in the keel of a barge near transverse bulkheads can reach unacceptably high values. The results obtained are confirmed by FEM calculations of a three-dimensional model of the barge.

Study of ECAE Process by Using FEM

2006 ◽  
Vol 526 ◽  
pp. 193-198 ◽  
Author(s):  
Rodrigo Luri ◽  
C.J. Luis-Pérez
Keyword(s):  
Cross Section ◽  
Strain Field ◽  
Equal Channel Angular Extrusion ◽  
Three Dimensional ◽  
Extrusion Process ◽  
The Finite Element Method ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Circular Section ◽  
Processed Material

In this work, the strain field attained by using a severe plastic deformation (SPD) process called equal channel angular extrusion (ECAE) is studied by the finite element method (FEM). The three-dimensional model with circular section includes shear friction between the part and the die, the material strain hardening behaviour and a rigid-deformable contact between the billet and the die. In the ECAE process the part is extruded through two channels with similar diameter that intersect at an angle. When the extrusion process has been performed, the processed material remains it cross section, so there is not any geometric limitation to achieve the desired plastic strain. There are different ways of processing the material by using the ECAE process; those ways of processing are called routes. In this work two passages of route C have been simulated. Using route C means that the billet has been rotated 180º between each passage. Deformations imparted to the processed material have been calculated and a comparison with experimental results has been carried out.

Dynamic Response of Bridge Girder and Shear Keys Subjected to Pounding during Earthquakes

2013 ◽  
Vol 339 ◽  
pp. 515-519
Author(s):  
Lu He ◽  
Lu Zhang ◽  
Jia Yong Chen ◽  
Chu Dong Pan ◽  
Yu Xiang Liu
Keyword(s):  
Dynamic Response ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Movement Characteristics ◽  
Shear Keys ◽  
Continuous Girder Bridge ◽  
Bridge Girder ◽  
Girder Bridge

Shear keys have been widely used to control the damage in abutments and piles during earthquakes. To investigate the dynamic response of bridge girder and traverse shear keys subjected to pounding, a three dimensional model of continuous girder bridge is developed in this study. With the assistance of the finite element method program ANSYS and the package LS-DYNA, the pounding between bridge girder and shear keys is simulated. Subsequently, the stress and displacement responses of the model are analyzed, and the movement characteristics are presented.

Finite Element Analysis on the Steel Transmission Pole

2012 ◽  
Vol 594-597 ◽  
pp. 808-811 ◽  
Author(s):  
Yan Hai Wang ◽  
Wei Jiang ◽  
Hong Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Traditional Method ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Strength And Deformation ◽  
Reliable Basis

At present, the finite element method is used to calculate the strength and deformation of the steel transmission pole less. Using ANSYS to model steel transmission pole, loading, analysis, the results show that, the traditional method of strength calculation and finite element analysis results are very close, the traditional method of deformation calculation and finite element analysis results has a certain bias. As long as the establishment of three-dimensional model of the steel transmission pole, the applied load and boundary conditions to meet the actual, finite element analysis can provide a more reliable basis for the design and verification of the steel transmission pole.

scholarly journals Strength analysis of an off-road lorry frame

2021 ◽  
Vol 110 ◽  
pp. 23-33
Author(s):  
Ján DIŽO ◽  
Miroslav BLATNICKÝ ◽  
Paweł DROŹDZIEL ◽  
Stanislav SEMENOV ◽  
Evgeny MIKHAILOV ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Degrees Of Freedom ◽  
Structural Unit ◽  
Three Dimensional ◽  
Strength Analysis ◽  
The Finite Element Method ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Definition Of ◽  
Distribution Of Stresses

The lorry frame is the main carrying part of a lorry, composed of several components. These components are connected by joints into one structural unit and it forms the lorry chassis. The contribution of this article is focused on the strength analyses of a backbone frame, which is used on an off-road lorry chassis. Strength analyses are carried out utilising the finite element method. This article presents a created three-dimensional model of the frame and definition of boundary conditions (loads, the definition of degrees of freedom) needed for simulation computations. Results of the numerical calculations are the main parts of this article. Attention is mainly centred on the distribution of stresses of the frame under defined loads and its deformations.

scholarly journals Construction project of a long reach compact excavator

2021 ◽  
Vol 4 (4) ◽  
pp. 341-356
Author(s):  
Grzegorz Chomka ◽  
Michał Kondaszewski
Keyword(s):  
Construction Project ◽  
Three Dimensional ◽  
Optimal Solution ◽  
Operating Conditions ◽  
Technical Documentation ◽  
The Finite Element Method ◽  
Dimensional Model ◽  
Operational Parameters ◽  
Three Dimensional Model ◽  
Standard Operating

The purpose of thesis was to comprehensively develop the construction project of a long reach compact excavator. Optimal solution was selected and its frames were determined by carrying out classic structural calculations. Then, based on them, a preliminary three-dimensional model was designed in the CAD environment. The prototype was subjected to a series of verification calculations and simulation tests using the finite element method under typical, but also non-standard operating conditions. Then, the structure was optimized and then tested again. Next, technical documentation of the final version was created. In the final part of work, technical and operational parameters of designed compact excavator were summarized and the direction of further actions was determined. The thesis ended with a summary of the observations arose during its implementation.

scholarly journals Determination of hydraulic steam losses in the turbine control valve based on a three-dimensional model

Vestnik IGEU ◽  
2019 ◽  
pp. 12-23
Author(s):  
V.A. Gorbunov ◽  
N.A. Lonshakov ◽  
I.V. Alekseyev ◽  
M.N. Mechtayeva
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Steam Turbine ◽  
Three Dimensional ◽  
Control Valve ◽  
The Finite Element Method ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Hydraulic Losses ◽  
Measuring Devices

A problem to be solved now is determining the hub nodes of hydraulic losses arising during the operation of power plant equipment. Detection of such points directly by measuring devices on the operating equipment is impossible as it is difficult to access many elements of the flow part of the units. Development of digital models of equipment allows simulating these processes and with a high degree of accuracy determining the location of increased hydraulic losses. The aim of this work is to determine the magnitude and localization of hydraulic losses in the control valve of the steam turbine. The analysis of steam turbine valve operation has been carried out based on thermodynamic, hydraulic and mechanical parameters, which are taken directly during the operation of the power plant by standard control and measuring devices. The obtained information was processed by the finite element method in the Ansys and SolidEdge Flow Simulation programs and by three-dimensional modeling in the SolidEdge software package. We have obtained a three-dimensional model of the control valve and determined the fields of pressure, velocity, etc. distribution in the volume of the control valve under different operating conditions by the finite element method. During the processing of the obtained information, we found excessive energy losses of water vapor arising during its throttling in the control valve. Such losses produce a significant effect on the power developed by the turbine pump. During the operation of the drive turbine, the pressure losses of the working medium in the steam distribution system vary in the range of 300–500 kPa (37–62 % of the initial pressure before the control valve). The goal set in the work has been fully achieved. Verification of the developed three-dimensional model was made on the basis of the operational parameters taken during the steam turbine operation. The application of the work results, both for modernizing the existing units and designing new equipment, will increase the efficiency of electric energy production at the power unit of the station.

The Analysis of Torsional Vibration of Coiler Drive System

2013 ◽  
Vol 455 ◽  
pp. 232-235
Author(s):  
Xue Wen Sun ◽  
Hai Bo Yang
Keyword(s):  
Cold Rolling ◽  
Three Dimensional ◽  
Drive System ◽  
The Finite Element Method ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Design And Manufacturing ◽  
Rolling Production ◽  
Dynamics Characteristic

Coiler is a very important equipment in the aluminum cold rolling production line. It plays an important role in improving the quality of the strip. In this essay, taken the aluminum cold rolling coiler drive system as the research object, in order to studying its dynamics characteristic, three-dimensional model has been built based on the finite element method. With the model, the aluminums weight has been verified, frequency and modal have been discussed, and the dangerous speed zone has been built by the first frequency. The result could serve as theoretical base for coiler design and manufacturing process.

Effect of Slit Structure of Purging Plug on Stress Field

2011 ◽  
Vol 418-420 ◽  
pp. 884-887 ◽  
Author(s):  
Xiao Xiao Huang ◽  
Wen Dong Xue ◽  
Jie Liu ◽  
Fa Han
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Field ◽  
Boundary Conditions ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
The Finite Element Method ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Length Width

The three-dimensional model of purging plug was analyzed by the finite element method. The influence of slit structure (length, width, center radius and numbers) on the maximum principal stress was Contrastive studied in argon blowing process under the same boundary conditions.

scholarly journals Investigation of Alardinskaya mine coal bumps causes using computer simulation of rock massif stress conditionals

2021 ◽  
Vol 326 ◽  
pp. 00008
Author(s):  
Andrey Sidorenko ◽  
Vyacheslav Alekseev ◽  
Yury Sirenko
Keyword(s):  
Finite Element Method ◽  
Computer Simulation ◽  
Three Dimensional ◽  
Diagonal Entry ◽  
Support Pressure ◽  
The Finite Element Method ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Safe Technology ◽  
Coal Bumps

The purpose of the paper was to identify the causes of rock bumps that occurred at the Alardinskaya mine (Russia) in 2011. The research was carried out using the finite element method. The developed three-dimensional model of the rock mass included a coal seam, rocks bedding above and below, goaf, and a system of local preparatory workings. The situation that arose immediately before the first rock burst was modeled during the research - when the longwall crossed a diagonal entry. The performed investigations enabled the authors to make a conclusion about a high danger of using technological schemes for the development of seams by longwalls leaving pillars that have a width less than the length of the support pressure zone, especially due to diagonal entries. As a safe technology for the longwall development of seams prone to rock bursts, it is recommended to apply a technological scheme with the abandonment of wide barrier pillars and four preparatory workings in each section, which has proven itself in the processing of rock bump hazardous seams in the state of Utah (USA).

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