ESTIMATION OF PARAMETERS OF STRENGTH AND RELIABILITY OF A SECTION OF A STEEL GAS PIPELINE TAKING INTO ACCOUNT VERTICAL SECTIONS ON THE NOVODEVICHY DUKER PROJECT WITH APPLICATION OF NUMERICAL METHODS

2020 ◽  
pp. 24-26
Author(s):  
G. Kh. Murzakhanov ◽  
A. A. Barsukov ◽  
A. S. Semenov ◽  
A. V. Makshin
Keyword(s):  
Finite Element ◽  
Numerical Methods ◽  
Gas Pipeline ◽  
Strength Calculation ◽  
Estimation Of Parameters ◽  
City Center ◽  
Pipeline Section ◽  
Moscow City ◽  
Vertical Sections ◽  
The Stability

Article considered main stages of strength calculation of the steel gas pipeline under the Novodevichy Duker project. Specialists of the Moscow city Center used the basis of the finite element for calculation. The list of tasks consists of: 1. Strength calculation of the underground laying gas pipeline section. 2. The calculation of the stability of the two vertical sections. According to the results of strength calculation, specialists made the conclusion about ensuring the strength and stability of the considered section of the gas pipeline.

CALCULATION OF REFERENCE REACTIONS AND AXIAL STROKE OF A SECTION OF A STEEL GAS PIPELINE FOR THE OBJECT “ROOF GAS BOILER HOUSE”

2021 ◽  
pp. 24-26
Author(s):  
G. Kh. Murzakhanov ◽  
A. A. Barsukov ◽  
A. S. Semenov ◽  
A. V. Makshin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boiler House ◽  
Gas Pipeline ◽  
Strength Calculation ◽  
The Finite Element Method ◽  
City Center ◽  
Moscow City ◽  
Element Method

The main stages of the strength calculation of a steel gas pipeline attached to the facade of a building, to determine the values of reference reactions, as well as the axial stroke of bellows compensators for the Roof gas boiler project are considered. The calculation was made on the basis of the finite element method by specialists in the Moscow city Center. Based on the results of the strength calculation, it was concluded that the strength and reliability of the considered section of the gas pipeline is ensured.

scholarly journals Stope Stability Assessment and Effect of Horizontal to Vertical Stress Ratio on the Yielding and Relaxation Zones Around Underground Open Stopes Using Empirical and Finite Element Methods

2017 ◽  
Vol 62 (3) ◽  
pp. 653-669 ◽  
Author(s):  
Mohammadali Sepehri ◽  
Derek Apel ◽  
Wei Liu
Keyword(s):  
Finite Element ◽  
Numerical Methods ◽  
Stress Ratio ◽  
Three Dimensional ◽  
Element Model ◽  
Underground Mine ◽  
Graph Method ◽  
The Stability ◽  
Stability Graph ◽  
The Impact

AbstractPredicting the stability of open stopes can be a challenging task for underground mine engineers. For decades, the stability graph method has been used as the first step of open stope design around the world. However, there are some shortcomings with this method. For instance, the stability graph method does not account for the relaxation zones around the stopes. Another limitation of the stability graph is that this method cannot to be used to evaluate the stability of the stopes with high walls made of backfill materials. However, there are several analytical and numerical methods that can be used to overcome these limitations. In this study, both empirical and numerical methods have been used to assess the stability of an open stope located between mine levels N9225 and N9250 at Diavik diamond underground mine. It was shown that the numerical methods can be used as complementary methods along with other analytical and empirical methods to assess the stability of open stopes. A three dimensional elastoplastic finite element model was constructed using Abaqus software. In this paper a sensitivity analysis was performed to investigate the impact of the stress ratio “k” on the extent of the yielding and relaxation zones around the hangingwall and footwall of the understudy stope.

The Definition of a Critical Deflection of Compressed Rods with the Creep by the Method of Bubnov-Galerkin

2018 ◽  
Vol 931 ◽  
pp. 127-132
Author(s):  
Batyr M. Yazyev ◽  
Serdar B. Yazyev ◽  
Anatoly P. Grinev ◽  
Elena A. Britikova
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Methods ◽  
Difference Method ◽  
Stability Problem ◽  
The Finite Element Method ◽  
The Difference ◽  
The Stability ◽  
Definition Of ◽  
The Galerkin Method

The comparison of the numerical methods: the finite element method, the Galerkin Method, the difference method is considered for the study of the stability of the rods. The dependence of the solution of the stability problem on the parameters of the discretization of these numerical methods is studied. It is shown that the mathematical models are sufficiently accurate to analyze the stability of the rods of constant and variable sections.

Research of Force in Piercing Process by FEM Simulation

2012 ◽  
Vol 482-484 ◽  
pp. 62-65 ◽  
Author(s):  
Lu Lu ◽  
Zhao Xu Wang ◽  
Fu Zhong Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Methods ◽  
Fem Simulation ◽  
Dynamic Evolution ◽  
Physical Parameters ◽  
The Finite Element Method ◽  
Simulation Results ◽  
The Stability ◽  
Future Plans

In this paper, the finite element method (FEM) is used for simulation of piercing process of the tube in Mannesmann mill. The sensitivity of the simulation results to numerical methods and physical parameters is discussed. The simulated results visualize dynamic evolution of force in the piercing process. The stability of the process and force condition is analyzed by FEM simulation. The model is verified by comparing the values of calculated force parameters and those measured in laboratory conditions. Finally, the future plans are presented.

scholarly journals Comparison between the finite differences, finite volume and finite element methods for the modelling of convective drying of fruit slices

2018 ◽  
Author(s):  
Fabian Leonardo Moreno ◽  
Adriana María Castro ◽  
Edgar Yesid Mayorga
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Numerical Methods ◽  
Finite Volume ◽  
Finite Differences ◽  
Convective Drying ◽  
Mathematical Treatment ◽  
Air Velocity ◽  
Method Selection ◽  
The Stability

Three numerical methods, finite differences, finite volume and finite element, were compared to know their convenience in the simulation of convective drying of fruit slices. The mathematical treatment, the stability, the convergence and the sensibility were analysed for each method. The data of the simulations were compared with the data of feijoa dried at 60°C, 5 mm of thickness and air velocity of 0.5ms-1. The error was 7%, 13% and 17% for finite element, finite volume and finite differences respectively. The method selection depends on the software, the required data precision and the use of the model. Keywords: mathematical model; convective drying; numerical methods 

Upon Impact Numerical Modeling of Foam Materials

2017 ◽  
Vol 54 (2) ◽  
pp. 195-202
Author(s):  
Vasile Nastasescu ◽  
Silvia Marzavan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modeling ◽  
Numerical Analysis ◽  
Numerical Methods ◽  
Boundary Conditions ◽  
General Character ◽  
Foam Material ◽  
Various Boundary Conditions ◽  
Specific Behaviour

The paper presents some theoretical and practical issues, particularly useful to users of numerical methods, especially finite element method for the behaviour modelling of the foam materials. Given the characteristics of specific behaviour of the foam materials, the requirement which has to be taken into consideration is the compression, inclusive impact with bodies more rigid then a foam material, when this is used alone or in combination with other materials in the form of composite laminated with various boundary conditions. The results and conclusions presented in this paper are the results of our investigations in the field and relates to the use of LS-Dyna program, but many observations, findings and conclusions, have a general character, valid for use of any numerical analysis by FEM programs.

scholarly journals Inlay-Retained Dental Bridges—A Finite Element Analysis

2021 ◽  
Vol 11 (9) ◽  
pp. 3770
Author(s):  
Monica Tatarciuc ◽  
George Alexandru Maftei ◽  
Anca Vitalariu ◽  
Ionut Luchian ◽  
Ioana Martu ◽  
...  
Keyword(s):  
Finite Element ◽  
Young Patients ◽  
Maximum Pressure ◽  
Class Iii ◽  
Element Analysis ◽  
Dental Prostheses ◽  
Abutment Teeth ◽  
Fixed Dental Prostheses ◽  
Implant Therapy ◽  
The Stability

Inlay-retained dental bridges can be a viable minimally invasive alternative when patients reject the idea of implant therapy or conventional retained full-coverage fixed dental prostheses, which require more tooth preparation. Inlay-retained dental bridges are indicated in patients with good oral hygiene, low susceptibility to caries, and a minimum coronal tooth height of 5 mm. The present study aims to evaluate, through the finite element method (FEM), the stability of these types of dental bridges and the stresses on the supporting teeth, under the action of masticatory forces. The analysis revealed the distribution of the load on the bridge elements and on the retainers, highlighting the areas of maximum pressure. The results of our study demonstrate that the stress determined by the loading force cannot cause damage to the prosthetic device or to abutment teeth. Thus, it can be considered an optimal economical solution for treating class III Kennedy edentation in young patients or as a provisional pre-implant rehabilitation option. However, special attention must be paid to its design, especially in the connection area between the bridge elements, because the connectors and the retainers represent the weakest parts.

scholarly journals Out-of-plane local mechanism analysis with finite element method

2021 ◽  
Vol 8 (1) ◽  
pp. 130-136
Author(s):  
Roberto Spagnuolo
Keyword(s):  
Finite Element ◽  
Masonry Walls ◽  
Finite Element Models ◽  
Mechanism Analysis ◽  
Fem Method ◽  
Local Mechanism ◽  
Out Of Plane ◽  
Smeared Crack ◽  
The Stability ◽  
No Tension Material

Abstract The stability check of masonry structures is a debated problem in Italy that poses serious problems for its extensive use. Indeed, the danger of out of plane collapse of masonry walls, which is one of the more challenging to evaluate, is traditionally addressed not using finite element models (FEM). The power of FEM is not properly used and some simplified method are preferred. In this paper the use of the thrust surface is suggested. This concept allows to to evaluate the eccentricity of the membrane stresses using the FEM method. For this purpose a sophisticated, layered, finite element with a no-tension material is used. To model a no-tension material we used the smeared crack method as it is not mesh-dependent and it is well known since the early ’80 in an ASCE Report [1]. The described element has been implemented by the author in the program Nòlian by Softing.

scholarly journals Stability charts based on the finite element method for underground cavities in soft carbonate rocks: validation through case-study applications

2019 ◽  
Vol 19 (10) ◽  
pp. 2079-2095 ◽  
Author(s):  
Michele Perrotti ◽  
Piernicola Lollino ◽  
Nunzio Luciano Fazio ◽  
Mario Parise
Keyword(s):  
Finite Element ◽  
Safety Margin ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Geometrical Features ◽  
Overall Stability ◽  
Underground Cavities ◽  
The Stability ◽  
Rock Mechanical Properties

Abstract. The stability of man-made underground cavities in soft rocks interacting with overlying structures and infrastructures represents a challenging problem to be faced. Based upon the results of a large number of parametric two-dimensional (2-D) finite-element analyses of ideal cases of underground cavities, accounting for the variability both cave geometrical features and rock mechanical properties, specific charts have been recently proposed in the literature to assess at a preliminary stage the stability of the cavities. The purpose of the present paper is to validate the efficacy of the stability charts through the application to several case studies of underground cavities, considering both quarries collapsed in the past and quarries still stable. The stability graphs proposed by Perrotti et al. (2018) can be useful to evaluate, in a preliminary way, a safety margin for cavities that have not reached failure and to detect indications of predisposition to local or general instability phenomena. Alternatively, for sinkholes that already occurred, the graphs may be useful in identifying the conditions that led to the collapse, highlighting the importance of some structural elements (as pillars and internal walls) on the overall stability of the quarry system.

Modal Analyses of Deployable Truss Structures Based on Shape Memory Polymer Composites

2016 ◽  
Vol 08 (07) ◽  
pp. 1640009 ◽  
Author(s):  
Fengfeng Li ◽  
Liwu Liu ◽  
Xin Lan ◽  
Tong Wang ◽  
Xiangyu Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Shape Memory ◽  
Polymer Composites ◽  
Dynamic Properties ◽  
Low Cost ◽  
Shape Memory Polymer ◽  
Truss Structures ◽  
Modal Test ◽  
The Stability ◽  
Mechanical Devices

With large spatial deployable antennas used more widely, the stability of deployable antennas is attracting more attention. The form of the support structure is an important factor of the antenna’s natural frequency, which is essential to study to prevent the resonance. The deployable truss structures based on shape memory polymer composites (SMPCs) have made themselves feasible for their unique properties such as highly reliable, low-cost, light weight, and self-deployment without complex mechanical devices compared with conventional deployable masts. This study offers deliverables as follows: an establishment of three-longeron beam and three-longeron truss finite element models by using ABAQUS; calculation of natural frequencies and vibration modes; parameter studies for influence on their dynamic properties; manufacture of a three-longeron truss based on SMPC, and modal test of the three-longeron truss. The results show that modal test and finite element simulation fit well.

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