scholarly journals An influence of shroud design parameters on the static stresses of blade assemblies

2019 ◽  
Vol 304 ◽  
pp. 03002
Author(s):  
Kyrylo Savchenko ◽  
Anatoliy Zinkovskii ◽  
Romuald Rzadkowski ◽  
Radoslaw Przysowa ◽  
Vadym Kruts
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Structural Analysis ◽  
Rotation Axis ◽  
Turbine Rotor ◽  
Rotor Blades ◽  
Design Parameters ◽  
The Finite Element Method ◽  
Calculation Results ◽  
Contact Surfaces

In this study, the structural analysis of the blade assemblies was carried out using the finite element method to determine the influence of design parameters of shroud couplings on the static stresses of turbine rotor blades with zigzag and slant shroud couplings. An angle of inclination of the shroud contact surfaces with respect to the rotor rotation axis was selected as the design parameter. Based on the calculation results, it has been found that irrespective of the type of the shroud coupling, the values of the contact pressure and the stresses in the shroud increase with the angle of inclination of the contact surfaces. Also, for the slant shroud coupling, the stresses increase in the blade airfoil portion with the increase of angle of inclination of the contact surfaces, while for the zigzag shroud coupling the contact stresses decrease with the increase of this angle. It was concluded that the zigzag shroud coupling causes the increase in static stresses when compared to the slant one.

DESIGN FEATURES OF CARBIDE ASSEMBLY WORKING ELEMENTS OF DEFORMING BROACHES

2021 ◽  
pp. 134-142
Author(s):  
Я.Б. Немировский ◽  
И.В. Шепеленко ◽  
С.Е. Шейкин ◽  
Ю.А. Цеханов ◽  
Ф.Й. Златопольский ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modeling ◽  
Hard Alloy ◽  
Contact Surface ◽  
Design Parameters ◽  
The Finite Element Method ◽  
Design Features ◽  
Working Element ◽  
External Loads

Разработан алгоритм и проведена оценка прочности сборных твердосплавных элементов со сплошной и дискретной рабочими поверхностями. Получены зависимости, позволяющие установить связь между конструктивными параметрами сборных деформирующих инструментов и их прочностью. Выполнены прочностные расчеты деформирующего инструмента для обработки отверстий значительного диаметра со сплошной и дискретной рабочими поверхностями. Численным моделированием, методом конечных элементов получены распределения эквивалентных напряжений в элементах инструмента и контактных напряжений по поверхности контакта твердосплавная вставка-корпус, что позволило проанализировать прочность инструмента под нагрузкой. Определены конструктивные параметры инструмента и приведены алгоритмы последовательности расчета сборных деформирующих элементов (ДЭ). Разработан алгоритм последовательности расчета сборного ДЭ для дискретного протягивания. Предложенная конструкция сборного рабочего элемента позволяет не только улучшить обрабатываемость изделия резания, но и уменьшить расход остродефицитного твердого сплава по сравнению с твердосплавным ДЭ аналогичных размеров на 6 кг. Полученные результаты можно использовать в инженерных расчетах при проектировании сборного инструмента для дискретного деформирования, а также для оценки прочности сборных инструментов, например, фрез, зенкеров, разверток при уточнении внешних нагрузок We developed an algorithm and assessed the strength of prefabricated carbide elements with solid and discrete working surfaces. We obtained dependencies that make it possible to establish a relationship between the design parameters of prefabricated deforming tools and their strength. We performed strength calculations of the deforming tool for machining holes of significant diameter with solid and discrete working surfaces. We obtained the distributions of equivalent stresses in the elements of the tool and contact stresses over the contact surface of the hard-alloy insert - body by numerical modeling, by the finite element method, which made it possible to analyze the strength of the tool under load. We determined the design parameters of the tool and here we give algorithms for the sequence of calculation of prefabricated deforming elements (DE). We developed an algorithm for the sequence of calculating the prefabricated DE for discrete broaching. The proposed design of the prefabricated working element allows not only to improve the machinability of the cutting product but also to reduce the consumption of an acutely deficient hard alloy in comparison with a hard alloy DE of similar dimensions by 6 kg. The results obtained can be used in engineering calculations when designing a prefabricated tool for discrete deformation, as well as for assessing the strength of prefabricated tools, for example, cutters, countersinks, reamers when specifying external loads

scholarly journals INFORMATIZATION OF CONSTRUCTION MANAGEMENT AS A BASIS FOR PREVENTING MAN-MADE ACCIDENTS

2021 ◽  
Vol 4 (4) ◽  
pp. 11-31
Author(s):  
S. Koryagina
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
The Finite Element Method ◽  
Calculation Results ◽  
Definition Of ◽  
Deep Pits ◽  
Geotechnical Problems ◽  
Seismic Impacts ◽  
Base Structure ◽  
Element Method

the article presents the principles and algorithms of the finite element method in solving geotechnical prob-lems taking into account seismic impacts for determining the stress-strain state of structures and slope stabil-ity, implemented in the Midas GTS NX software package. GTS NX allows you to perform calculations of various types of geotechnical problems and solve complex geotechnical problems in a single software envi-ronment. GTS NX covers the entire range of engineering and geotechnical projects, including calculations of the "base-structure" system, deep pits with various mounting options, tunnels of complex shape, consolida-tion and filtration calculations, as well as calculations for dynamic actions and stability calculations. At the same time, all types of calculations in GTS NX can be performed both in 2D and in 3D. The author does not claim to be the author of the finite element method, but he cannot do without pointing out the basic equa-tions, as this affects the definition of the boundaries of use, the formulation of algorithms for constructing calculation schemes and the analysis of calculation results.

Analysis by the mixed method of statically indeterminate frames with elements of increased rigidity and numerical verification of the calculation results using the finite element method

2021 ◽  
Vol 14 (2) ◽  
pp. 54-66
Author(s):  
Svetlana Sazonova ◽  
Viktor Asminin ◽  
Alla Zvyaginceva
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Initial Data ◽  
Mixed Method ◽  
Numerical Verification ◽  
Bending Moments ◽  
The Finite Element Method ◽  
Calculation Results ◽  
Internal Forces ◽  
Element Method

The sequence of application of the mixed method for calculating internal forces in statically indeterminate frames with elements of increased rigidity is given. The main system is chosen for the frame with one kinematic and one force unknown. The canonical equations of the mixed method are written, taking into account their meaning. Completed the construction of the final diagram of the bending moments and all the necessary calculations and checks. When calculating integrals, Vereshchagin's rule is applied. The solution of the problem is checked by performing the calculation using the computer program STAB12.EXE; the results of the calculations are numerically verified using the finite element method. An example of the formation of the initial data for the STAB12.EXE program and the subsequent processing of the calculation results, the rules for comparing the numerical results and the results obtained in the calculation of the frame by the mixed method are given.

Pipeline On-Bottom Stability Analysis Based on FEM Model

2011 ◽  
Author(s):  
Yong Bai ◽  
Zhimeng Yu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Design Procedure ◽  
Element Model ◽  
The Finite Element Method ◽  
Fem Model ◽  
Engineering Software ◽  
Calculation Results ◽  
Pipeline Design ◽  
Element Method

Pipeline on-bottom stability is one of the sophisticated problems in subsea pipeline design procedure. Due to the uncertainty of the pipe-soil interaction and environment loads, including wave, current, or earthquake, etc., it is classified as the typical nonlinear problem. The Finite Element Method is introduced into pipeline engineering several years ago. More and more special engineering software such as AGA, PONDUS are available in market. However, when doing a project, some abnormal data was found when compared the DnV calculation results and AGA. In order to know the behavior of pipeline on seabed under wave and current load, finite element method – ABAQUS is introduced to do this analysis. The ABAQUS/explicit is used to simulate 600s pipeline dynamic response. The pipeline is supposed to be exposed on seabed and the selected seabed model is large enough to avoid the edge effect. ABAQUS calculation results are compared with the requirements in DnV rules to verify the validity of finite element model.

Piezoelectric “Kumihimo-gumi” sensor fabricated by braiding method using piezoelectric poly-L-lactic acid fiber

2020 ◽  
Vol 557 (1) ◽  
pp. 43-57 ◽  
Author(s):  
Y. Tajitsu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Lactic Acid ◽  
Polyethylene Terephthalate ◽  
Wearable Sensor ◽  
The Finite Element Method ◽  
Complex Motion ◽  
Calculation Results ◽  
New Type ◽  
Plla Fiber

We have developed a piezoelectric braided cord consisting of a conducting fiber yarn core, piezoelectric poly-l-lactic acid (PLLA) fiber yarn and a polyethylene terephthalate (PET) middle sheath, and a conducting fiber outer shield (piezoelectric PLLA braided cord). Actually, we made various types of piezoelectric PLLA braided cords using Japanese traditional braiding method called as Kumihimo-gumi in Japanese. Furthermore, by optimization based on the calculation results for each type of piezoelectric PLLA Kumihimo-gumi obtained by the finite element method (FEM), we were able to develop a new type of piezoelectric PLLA braided cord with a sensing function for complex motion (piezoelectric PLLA Kumihimo-gumi). Finally, we developed a new wearable sensor for a selfie stick which is a popular smartphone accessory, fabricated from a piezoelectric PLLA Kumihimo-gumi.

scholarly journals Determining internal forces in modular building elements under action wind load

2018 ◽  
Vol 196 ◽  
pp. 02010
Author(s):  
Viacheslav Shirokov ◽  
Alexey Soloviev ◽  
Tatiana Gordeeva
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Section ◽  
Dynamic Characteristics ◽  
Wind Load ◽  
Wind Loads ◽  
Bending Moments ◽  
The Finite Element Method ◽  
Calculation Results ◽  
Internal Forces

The research paper focuses on internal forces determination in the elements of modular buildings under wind load. It provides a methodology for determining dynamic characteristics of a building and for calculating wind loads. This method is based on the following assumptions: coupling of the modules elements is rigid; coupling of block-modules with foundations is hinged-fixed; connection of blocks to each other is hinged in angular points; the floor disk in its plane is not deformed. On the basis of these assumptions the authors derived approximate and refined equations for determining forces in modules elements under static and pulsation components of wind load. The equation of bending moments determination in the pillar bearing cross-section is obtained by approximation of the graph of moments variation, calculated for the spectrum of the ratio of the pillar stiffness and the floor beam in the range from 1/64 to 64. The paper further introduces the calculation results of forces based on the proposed methodology and on the finite element method. The calculations were done while taking different values of wind load and different number of storeys in a building (from 1 to 4 floors). The obtained results are similar, the error does not exceed 5%.

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