ANALYSIS OF THE COMBINED STRUCTURE OF THE SHAFT OF THE DNIPRO METRO BY THE FINITE ELEMENTS METHOD

Purpose. The development of construction of underground excavations of the Dnipro Metro requires analysis and scientific substantiation of design solutions based on technologies that are new for Ukraine. The aim of the scientific article is to analyze the combined design of the shaft of the Dnipro Metro by the finite element method with determination of force factors in the linings of the pile system and shotcrete system with further substantiation based on the results of design solutions to the real situation of Dnipro Metro construction. Methodology. Two finite element models were constructed for the analysis of the shaft № 1 of the Dnipro Metro by the finite element method. They reflect the combined design of the shaft, which consists of two parts. The finite-element model of the pile system, which reflects the shell of bored piles, supported by a cap beam and ring beams, is analyzed separately. The model for the shotcrete system, which is used for the second part of the shaft, which lies in a solid rock mass, is separately modeled and analyzed. Finite-element models of both systems are assigned real deformation and geometric parameters, as well as the load, which became the key to adequate calculations by the finite element method. Findings. During the numerical analysis of the combined structure of the shaft № 1 of Dnipro Metro, the force factors (normal forces and bending moments) for the pile system and the shotcrete system were determined. These results became the basis for the reinforcement of both systems. Originality. A numerical analysis of the shaft structure was performed, which provided a complete picture of the force factors that allow predicting the appearance of normal forces and bending moments in similar engineering and geological conditions. Practical value. The results of the analysis of the combined design of the shaft of the Dnipro Metro by the finite element method allowed to scientifically substantiate the design solutions and ensure high performance of both shaft systems № 1.

Download Full-text

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

Modeling of systems and processes ◽

10.12737/2219-0767-2021-14-2-54-66 ◽

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.

Download Full-text

Rock Bit Cutter Tooth Design and Analysis

Journal of Energy Resources Technology ◽

10.1115/1.3230893 ◽

1983 ◽

Vol 105 (2) ◽

pp. 138-144

Author(s):

G. C. Feng ◽

P. W. Schumacher

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Numerical Solutions ◽

Plastic Region ◽

Finite Element Models ◽

The Finite Element Method ◽

Stress Concentrations ◽

Property Changes ◽

Rock Bit ◽

Element Method

The finite element method was used to analyze the stresses in a rock bit cutter tooth under applied loads. Detailed finite element models were constructed to allow accurate descriptions of the structural material properties of a tooth design which includes carburization and hardmetal application. Numerical solutions were obtained for investigating stress concentrations and plastic region growths in a cutter tooth when loaded beyond its yield point. It was found that the finite element method can be a powerful tool for improving the performance of a cutter tooth. Design objectives can be achieved through parameteric studies of stress level variations against geometry and material property changes on a computer system.

Download Full-text

Analysis of Different Positions of Fiber-Reinforced Composite Retainers versus Multistrand Wire Retainers Using the Finite Element Method

International Journal of Biomaterials ◽

10.1155/2014/581029 ◽

2014 ◽

Vol 2014 ◽

pp. 1-5 ◽

Cited By ~ 5

Author(s):

Arezoo Jahanbin ◽

Mostafa Abtahi ◽

Farzin Heravi ◽

Mohsen Hoseini ◽

Hooman Shafaee

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Anterior Segment ◽

Finite Element Models ◽

The Finite Element Method ◽

Vertical Loading ◽

Segment Model ◽

Reinforced Composite ◽

Upper Third ◽

Element Method

Background.The aim of this study was to evaluate root displacement of the lower incisors fixed with FRC in different positions versus FSW retainers using the finite element method.Materials and Methods.3D finite element models were designed for a mandibular anterior segment: Model 1: flexible spiral wire bonded to the lingual teeth surfaces, Model 2: FRC bonded to the upper third of lingual teeth surfaces, and Model 3: FRC bonded to the middle third. FE analysis was performed for three models and then tooth displacements were evaluated.Results.In contrast to lateral incisors and canines, the FSW retainer caused the central teeth to move more than the teeth bonded with FRC in both loadings. Comparison between Models 2 and 3 (in vertical loading) showed that FRC retainers that bonded at the upper third of lingual teeth surfaces made central and canine teeth move less than FRC retainers bonded at the middle third; however, for lateral teeth it was the opposite.Conclusion.FRC retainers bonded at the upper third of lingual teeth surfaces make central and canine teeth move less than FRC retainers bonded at the middle third in vertical loading; however, for lateral teeth it was the opposite.

Download Full-text

Simulation of tuning graphene plasmonic behaviors by ferroelectric domains for self-driven infrared photodetector applications

Nanoscale ◽

10.1039/c9nr06508c ◽

2019 ◽

Vol 11 (43) ◽

pp. 20868-20875 ◽

Cited By ~ 1

Author(s):

Junxiong Guo ◽

Yu Liu ◽

Yuan Lin ◽

Yu Tian ◽

Jinxing Zhang ◽

...

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Interfacial Effect ◽

Infrared Photodetector ◽

The Finite Element Method ◽

Ferroelectric Domains ◽

Element Method

We propose a graphene plasmonic infrared photodetector tuned by ferroelectric domains and investigate the interfacial effect using the finite element method.

Download Full-text