scholarly journals Method of calculating the gear ratios of the cones of tricone drill bits

2020 ◽  
Vol 201 ◽  
pp. 01012
Author(s):  
Javokhir Toshov ◽  
Bakhtiyor Baratov ◽  
Umid Baynazov
Keyword(s):  
Optimization Problems ◽  
Functional Dependence ◽  
Physical And Mechanical Properties ◽  
Physical Nature ◽  
Geometrical Parameters ◽  
Rock Destruction ◽  
Drill Bits ◽  
Specific Contact ◽  
Objective Basis ◽  
Fracture Work

The process of rock destruction under dynamic impact on it through two technological criteria in the form of specific contact and specific volumetric fracture works is evaluated. Specific contact and specific volumetric fracture work are used to study the physical and mechanical properties of rocks. The efficiency of rock destruction during well drilling with tricone bits functionally depends on the relative specific contact and specific volumetric fracture work. It is stated that the criteria for evaluating the performance of tricone bits in certain forms are functions of the triad: bit-rock-energy. The disclosed physical nature of the kinetic criteria and the obvious functional dependence on the geometric parameters of these drill bits are an objective basis for constructing a methodology for improving the dynamics of new designs and modifications. The parameters of the kinetic passport of the bit are calculated and presented in tabular and graphical forms as functions corresponding to their coordinates of the cones of the roller cutters and the bottom of the well. Experience in solving optimization problems based on a comparative analysis of kinetic (dynamic) criteria has shown that a) when improving almost any design of a cone bit, it is necessary to use the initial geometrical parameters of the buttons and their number b) to ensure that the supports of adjacent cones are equally loaded along the path of leveling the minimum volumetric fracture work of crowns adjacent cones.

scholarly journals Perspective Solutions for the Design of Drilling Tools

2019 ◽  
Vol 105 ◽  
pp. 03027 ◽  
Author(s):  
Ulugbek Mannanov ◽  
Javokhir Toshov ◽  
Lazizjon Toshniyozov
Keyword(s):  
Energy Consumption ◽  
Dynamic Systems ◽  
Optimization Problems ◽  
Bottom Hole ◽  
Drill Bits ◽  
Drilling Tools

The article considers the ways to solve optimization problems of drill bits on a deterministic basis through studying and using the “Regularity of energy consumption of dynamic systems from resistance to motion forces”, which directly indicates the causes of bit balling formation, the reasons for the insufficient stability of the bearing assemblies of the cones, the causes of instability of the drill bits at the bottom of the well. Theoretical grounded search was done to use certain methods for designing drill bits of cutting-abrasive type, working in the rotational steam mode, which determine uniform wear of armaments for all crowns of working matrices and uniform destruction of the rock through all of the annular bottom hole.

Loading of bearing retaining pin of tricone drill bit

2020 ◽  
pp. 64-67
Author(s):  
D. I. Simisinov ◽  
◽  
A. I. Afanasiev ◽  
V. S. Shestakov ◽  
N. G. Valiev ◽  
...  
Keyword(s):  
Strain Analysis ◽  
Physical And Mechanical Properties ◽  
Contact Stresses ◽  
Drill Bit ◽  
Ministry Of Education ◽  
Drill Bits ◽  
Bending Loads ◽  
Bearing Assembly ◽  
Engineering Changes ◽  
Cone Drill

Improvement of cone drill bit design is an engineering challenge as it is connected with considerable energy to be transferred via the drill to well bottom in the limited well space. In such conditions, it is difficult to create a full-size bearing assembly, including bearings and lubricating devices, as well as the sufficiently efficient cutting structure of the bits. Moreover, the condition of equal lives of the cutting structure and the bearing assembly is to be fulfilled. The operating practice of tricone drill bits in shothole drilling reveals their low serviceability. The life of a bit ranges from a few hours to a few days subject to physical and mechanical properties of rocks. The main cause of bit failure is damage of the retaining pin shoulder rivet under high contact stresses. Aimed at improvement of cone drill bit design and justification of engineering changes, the stress–strain analysis of the bearing retaining pint is performed, and it is found that the pin shoulder rivet experiences essential contact stresses and bending loads. It is proposed to equip cone drill bits with circulation lubrication system for the bearing assembly. Lubrication improvement can ensure reduction in loading of the bearing assembly components and, consequently, provide higher durability and wear resistance of these parts. The study was supported by the Ministry of Education and Science of Russia according to the state contract with the Ural State Mining University, Contract No. 0833-2020-0007.

On the influence of the shaped charge liner manufacture technology on the high-speed element characteristics

2020 ◽  
Author(s):  
V.I. Kolpakov ◽  
N.A. Kudyukov
Keyword(s):  
High Speed ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Shaped Charge ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Liner Material ◽  
Metal Spinning ◽  
Cold Stamping ◽  
Physical And Mechanical Characteristics

The paper introduces the results of numerical simulation of the functioning of shaped charges, whose liners are made of different materials. As a result of their functioning, these charges form high-speed elements. Typically, liners for such charges are produced by the cold stamping technology. An alternative method for producing the liners is metal spinning. Moreover, a spin formed liner is expected to have higher physical and mechanical properties compared to a stamped liner made of the same material and having the same geometrical parameters. To reveal the patterns of molding high-speed elements from stamped and spin formed liners, the action of shaped charges comprised of steel or copper segmental liners of small bending, was simulated numerically using the apparatus of continuum mechanics. The influence of the liner manufacture method was taken into account by varying the values of the physical and mechanical characteristics of the liner material. The design parameters of the simulated charge, with the exception of the liner bending, during the calculation study remained unchanged and corresponded to the parameters of the currently used samples. Following the numerical experiments results, the study shows that the elements molded from spin formed liners are less likely to become fractured while being formed and are also more integral (continuous) in comparison to the elements molded from stamped shaped charge liners.

scholarly journals The Effect of Cobalt on the Deformation Behaviour of a Porous TiNi-Based Alloy Obtained by Sintering

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7584
Author(s):  
Nadezhda Artyukhova ◽  
Sergey Anikeev ◽  
Vladimir Promakhov ◽  
Maxim Korobenkov
Keyword(s):  
Deformation Behaviour ◽  
Structural Phase ◽  
Physical And Mechanical Properties ◽  
Physical Nature ◽  
Entire Area ◽  
Structural Phase State ◽  
Concentration Dependency ◽  
The Matrix ◽  
Research Findings ◽  
First Time

This research investigates the effect of cobalt on the deformation behaviour of a porous TiNi-based alloy that was obtained by sintering. Porous TiNi-based alloys with cobalt additives, accounting for 0–2 at. % and with a pitch of 0.5, were obtained. The structural-phase state of the porous material was researched by X-ray structural analysis. The effect of different amounts of Co (used as an alloying additive) on the deformation behaviour was investigated by tensile to fracture. The fractograms of fracture of the experimental samples were analysed using scanning electron microscopy. For the first time, the present research shows a diagram of the deformation of a porous TiNi-based alloy that was obtained by sintering under tensile. The stages of deformation were described according to the physical nature of the processes taking place. The effect of the cobalt-alloying additive on the change in the critical stress of martensitic shear was investigated. It was found that the behaviour of the concentration dependency of stress at concentrations under 1.5 at. % Co was determined by an increase in the stress in the TiNi solid solution. This phenomenon is attributed to the arrangement of Co atoms on the Ti sublattice, as well as an increase in the fraction of the B19′ phase in the matrix. The steep rise of the developed forces on the concentration dependency of the martensitic shear stress at 2 at. % Co is presumably attributed to the precipitation hardening of austenite due to the precipitation of finely dispersed coherent Ti3Ni4 phase following the decrease of fraction of martensite. An analysis of fractograms showed that as more cobalt was added, areas of fracture with traces of martensite plates of the B19′ phase started to prevail. At 2 at. % Co these plates fill almost the entire area of the fracture. The research findings presented in this work are of great importance, since they can be used to achieve the set of physical and mechanical properties required for the development of biocompatible materials for implantology.

scholarly journals Particle Swarm Optimization Algorithms with Applications to Wave Scattering Problems

2021 ◽  
Author(s):  
Alkmini Michaloglou ◽  
Nikolaos L. Tsitsas
Keyword(s):  
Particle Swarm Optimization ◽  
Wave Scattering ◽  
Optimization Problems ◽  
Particle Swarm ◽  
Pso Algorithm ◽  
Fine Tuning ◽  
Geometrical Parameters ◽  
Scattering Problems ◽  
Swarm Optimization ◽  
Feasible Solutions

Particle Swarm Optimization (PSO) algorithms are widely used in a plethora of optimization problems. In this chapter, we focus on applications of PSO algorithms to optimization problems arising in the theory of wave scattering by inhomogeneous media. More precisely, we consider scattering problems concerning the excitation of a layered spherical medium by an external dipole. The goal is to optimize the physical and geometrical parameters of the medium’s internal composition for varying numbers of layers (spherical shells) so that the core of the medium is substantially cloaked. For the solution of the associated optimization problem, PSO algorithms have been specifically applied to effectively search for optimal solutions corresponding to realizable parameters values. We performed rounds of simulations for the the basic version of the original PSO algorithm, as well as a newer variant of the Accelerated PSO (known as “Chaos Enhanced APSO”/ “Chaotic APSO”). Feasible solutions were found leading to significantly reduced values of the employed objective function, which is the normalized total scattering cross section of the layered medium. Remarks regarding the differences and particularities among the different PSO algorithms as well as the fine-tuning of their parameters are also pointed out.

scholarly journals Parametric optimization of steel structures based on gradient projection method

2020 ◽  
pp. 192-220
Author(s):  
Vitalina Yurchenko ◽  
Ivan Peleshko
Keyword(s):  
Parametric Optimization ◽  
Optimization Problems ◽  
Steel Structure ◽  
Steel Structures ◽  
Gradient Projection ◽  
Truss Structures ◽  
Design System ◽  
Geometrical Parameters ◽  
Structural Members ◽  
Load Case

The main research goal is the development of a numerical methodology for solving parametric optimization problems of steel structures with orientation on software implementation in a computer-aided design system. The paper has proposed a new mathematical model for parametric optimization problems of steel structures. The design variable vector includes geometrical parameters of the structure (node coordinates), cross-sectional dimensions of the structural members, as well as initial pre-stressing forces introduced into the specified redundant members of the structure. The system of constraints covers load-carrying capacities constraints formulated for all design sections of structural members of the steel structure subjected to all ultimate load case combinations. The displacements constraints formulated for the specified nodes of the steel structure subjected to all serviceability load case combinations have been also included into the system of constraints. The method of the objective function gradient projection onto the active constraints surface with simultaneous correction of the constraints violations has been used for solving the parametric optimization problem. A numerical algorithm for solving the formulated parametric optimization problems of steel structures has been developed in the paper. The comparison of the optimization results of truss structures presented by the paper confirms the validity of the optimum solutions obtained using the proposed numerical methodology.

Multilevel Hierarchical Decomposition: Identification Procedures for Edge of Design Space Feasibility

2006 ◽  
Author(s):  
Somanath Nagendra ◽  
Jeff Midgley ◽  
Joseph B. Staubach
Keyword(s):  
High Performance ◽  
Design Space ◽  
Optimization Problems ◽  
Functional Dependence ◽  
Minimum Weight ◽  
Design Feature ◽  
Turbine Disk ◽  
System Level ◽  
Optimum Shape ◽  
Design Variables

In high performance machines, multiple active MDO constraints dictate the edge of feasibility, i.e. boundary of the design space. It is essential to have an accurate description of the boundary in terms of design variables. Given a sample of data, the recognition of a design feature (e.g. design shape) is not usually familiar to the design domain experts but must be extracted based on data-driven procedures. The “edge of feasibility” could be evaluated as a continuous or piece wise continuous function of active constraints. In this work, the focus is on a class of quasiseparable optimization problems. The subsystems for these problems involve local design shape variables and global system variables, but no variables from other subsystems. The system in this particular case is the engine component (i.e. HPT) and the subsystem is the turbine disk. The system is hierarchically decomposed to the system and subsystem components respectively. The HPT flowpath and its defined thermodynamic and geometric parameters define the system. The subsystem is the HPT turbine disk and its associated geometric shape variables. A system level DOE determines the design space of the HPT system. The optimized subsystem turbine disk is the solution to the DOE of the system and feasible disk designs are the shapes that can withstand the design loads and stresses. The focus of the paper is to develop a methodology that would systematically utilize minimum weight optimum shape designs across the design space and predict new designs close to being optimal in performance for a specified range of design conditions. The shape of minimum weight disks are identified as a solution of a system of inverse response surface equations that can determine disk shapes with good confidence. The methodology is developed using synthetic turbine disk problems with known regions of feasibility and infeasibility. The edge of feasibility is determined and the functional dependence on the design variables estimated.

The static response of axisymmetric conical shells exhibiting bistable behavior

2021 ◽  
pp. 1-24
Author(s):  
Yair Luxenburg ◽  
Sefi Givli
Keyword(s):  
Finite Element ◽  
Radial Displacement ◽  
Functional Dependence ◽  
Building Blocks ◽  
Rigid Rotation ◽  
Finite Element Simulations ◽  
Analytical Models ◽  
Geometrical Parameters ◽  
Bistable Behavior ◽  
Conical Shells

Abstract Belleville springs are widely used in variety of mechanical systems. Recent advances in the field of multi-stable structures suggest that these conical axisymmetric washers may be extremely useful as bistable building-blocks for multi-stable architected metamaterials. In this paper, we examine the ability of existing analytical models to accurately predict the bistable behavior of Belleville springs, namely a non-monotonous force-displacement relation with two branches of positive stiffness separated by a branch of negative stiffness. By comparing to results of finite-element simulations, we find that current analytical models may suffer from significant inaccuracies associated with the assumption of rigid rotation. According to this assumption, adopted by all analytical models of Belleville springs, the cross-section of the spring rotates without bending, i.e. maintains zero curvature as the spring deforms. Motivated by this insight, we relax the rigid-rotation assumption and approximate the radial displacement field by a linear relation in terms of the distance from the spring axis. We find, based on extensive finite-element simulations, that the functional dependence of the radial displacement on the geometry of the springs is indifferent to the stage of deformation and can be expressed in terms of three geometrical parameters. These findings enable us to derive closed-form expressions that are simple and straight-forward to use, yet are significantly more accurate than existing analytical models.

The Method of Alternate Formulations Applied to Optimization Problems With Functionally Dependent State Equations

1989 ◽  
Author(s):  
C. R. Hammond ◽  
G. E. Johnson
Keyword(s):  
Optimization Problems ◽  
Functional Dependence ◽  
Numerical Approach ◽  
Upper And Lower Bounds ◽  
Decision Variable ◽  
State Equations ◽  
Reduced Gradient Method ◽  
Mathematical Properties ◽  
Reduced Gradient ◽  
Generalized Reduced Gradient

Abstract The Method of Alternate Formulations (MAF) is a non-numerical approach to constrained optimal design. MAF requires that the problem statement be transformed into an objective function, a set of equality-constraints (i.e. state equations), and a set of upper and lower bounds on the variables. In this format, the design vector can be partitioned into decision variable and state variable components. This is the same format as used in the solution of such problems by the generalized reduced gradient method. The fact that there are usually several ways to effect the partition of the design vector gives rise to the existence of alternate formulations. Each alternate formulation contains all of the information about the physical system — and the constrained optima are invariant under the transformation from form to form. Yet all other mathematical properties (e.g., convexity, linearity, scaling, etc.) can change. In this paper, we consider the special case when the state equations are functionally dependent, hence some of the expected constraint intersections do not exist. Several examples are used to demonstrate the concept of functional dependence and to show how functional dependence affects the search for the solution.

scholarly journals WOODWORKING IN THE NORTHERN BUKOVYNA DURING 12th — EARLY 13th CENTURIES

2020 ◽  
Vol 35 (2) ◽  
pp. 327-333
Author(s):  
I. P. Vozny
Keyword(s):  
Mechanical Properties ◽  
Economic Development ◽  
Middle Ages ◽  
Physical And Mechanical Properties ◽  
Archaeological Sites ◽  
Main Method ◽  
Fully Integrated ◽  
Drill Bits ◽  
Long Time ◽  
Technical Properties

The article deals with the development of woodworking industry in the medieval settlements of Northern Bukovyna which for a long time remained poor studied. During the Middle Ages this territory was covered with significant forest areas, in which there were 22 local breeds of both industrial and rare trees. Accordingly, the woodworking industry here, as well as throughout the territory of Old Rus, had many branches. Being well acquainted with the technical properties of wood the local masters widely used this knowledge depending on the physical and mechanical properties of the breed. Constructing fortifications they used mainly oak and beech, for residential and commercial buildings they used pine and fir. Hardwood (maple, ash) was spread in manufacturing of dishes, while spoons were made from the yarrow, juniper. The remains of precise or carved wooden dishes were discovered in the settlements of Northern Bukovyna. Beech and oak were used in the craft. Containers were made from lime to store loose materials. Local carpenters were aware of various ways of connecting individual wooden elements to each other in a particular product or construction. When erecting dwellings or household structures in corners, the main method was to connect the locks, and when connected horizontally, direct, overhead, spit joints were widely used. At the archaeological sites of Northern Bukovyna, as the open settlements were almost not explored, considerable woodworking toolkit was discovered. It is represented as forms and fragments of blades, ax, bits, drill bits, knives, nail, etc. Their typology has wide analogies among archeological materials from other territories of the Old Rus state and is fully integrated into the generally accepted typology. Thus, materials that characterize the woodworking industry of Northern Bukovyna completely allow trace the evolution of the woodworking business, which developed in terms of economic development of Old Rus.

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