scholarly journals Geometric Model of the Shaping of the Working Surfaces of the Bevel Gear Elements

2020 ◽  
pp. 48-58
Author(s):  
S. Ryazanov
Keyword(s):  
Solid State ◽  
Geometric Modeling ◽  
Block Diagram ◽  
Geometric Model ◽  
Bevel Gear ◽  
Final Shape ◽  
Technological Processes ◽  
3D Space ◽  
Solid Models ◽  
Tooth Surfaces

A method of solid-state geometric modeling of technological processes of the shaping of spatial gears in 3D space is proposed. Working and transition surfaces of the teeth are formed as envelopes of the generating surface of the tool. The result is the final shape of the tooth surfaces in the form of accurate computerized solid models. A block diagram and an example of "computer cutting" of a bevel gear are given.

scholarly journals The Method of High Accuracy Calculation of Robot Trajectory for the Complex Curves

2020 ◽  
Vol 28 (4) ◽  
pp. 247-252
Author(s):  
Alexander Lozhkin ◽  
Pavol Bozek ◽  
Konstantin Maiorov
Keyword(s):  
Calculation Method ◽  
Geometric Modeling ◽  
Classical Method ◽  
Geometric Model ◽  
New Method ◽  
Approximation Methods ◽  
Linear Transformations ◽  
Design Quality ◽  
Complex Curves ◽  
Internal Properties

AbstractThe geometric model accuracy is crucial for product design. More complex surfaces are represented by the approximation methods. On the contrary, the approximation methods reduce the design quality. A new alternative calculation method is proposed. The new method can calculate both conical sections and more complex curves. The researcher is able to get an analytical solution and not a sequence of points with the destruction of the object semantics. The new method is based on permutation and other symmetries and should have an origin in the internal properties of the space. The classical method consists of finding transformation parameters for symmetrical conic profiles, however a new procedure for parameters of linear transformations determination was acquired by another method. The main steps of the new method are theoretically presented in the paper. Since a double result is obtained in most stages, the new calculation method is easy to verify. Geometric modeling in the AutoCAD environment is shown briefly. The new calculation method can be used for most complex curves and linear transformations. Theoretical and practical researches are required additionally.

scholarly journals MODELING ARCHITECTURAL FORM SURFACE DEPENDENT SECTIONS

2021 ◽  
pp. 53-58
Author(s):  
A. A. Chekalin ◽  
M. K. Reshetnikov ◽  
V. V. Shpilev ◽  
S. V. Borodulina ◽  
S. A. Ryazanov
Keyword(s):  
Geometric Modeling ◽  
Geometric Model ◽  
Residential Building ◽  
Cubic Splines ◽  
Piecewise Smooth ◽  
Additional Parameter ◽  
Mathematical Apparatus ◽  
Surface Design ◽  
Fourth Degree ◽  
Architectural Form

For the design of surfaces in architecture, as a rule, universal techniques developed for other technical industries are used. First of all, these are general kinematic surfaces and interpolation cubic splines for modeling complex piecewise smooth surfaces. The authors propose to use the fourth degree inerodifferential spline developed by them for problems of geometric modeling of architectural forms. For calculations and constructions on a computer, the proposed spline is not much more complicated than traditional cubic splines, since it has one additional parameter - a coefficient. However, this allows you to locally control the shape of a curve or surface during design, that is, to change the shape in individual areas without affecting other areas. The article proposes a method for constructing a geometric model of the kinematic surface of dependent sections with a fourth degree parabola as a generator. When using cubic splines as a guide, the surface is a 3 × 4 non-uniform (heterogeneous) spline. The article shows that the surface on the basis of the proposed mathematical apparatus can be composite piecewise-smooth. A particular case of surface design is considered on the example of creating a model of the surface of the facade of a residential building according to the existing concept. The algorithm can be easily programmed and added as a tool to existing CAD systems.

BIOMECHANICAL MODEL PREDICTING VALUES OF MUSCLE FORCES IN THE SHOULDER GIRDLE DURING ARM ELEVATION

2010 ◽  
Vol 10 (04) ◽  
pp. 643-666 ◽  
Author(s):  
ERIC BERTHONNAUD ◽  
MELISSA MORROW ◽  
GUILLAUME HERZBERG ◽  
KAI-NAN AN ◽  
JOANNES DIMNET
Keyword(s):  
Geometric Modeling ◽  
Geometric Model ◽  
Contractile Element ◽  
Muscle Forces ◽  
Active Muscle ◽  
Cross Sectional ◽  
Shoulder Complex ◽  
Arm Elevation

A three-dimensional (3D) geometric model for predicting muscle forces in the shoulder complex is proposed. The model was applied throughout the range of arm elevation in the scapular plan. In vitro testing has been performed on 13 cadaveric shoulders. The objectives were to determine homogeneous values of physiological parameters of shoulder muscles and to locate sites of muscular attachment to any bone of the shoulder complex. Muscular fiber lengths, lengths of contractile element (CE), and muscle volumes were measured, corresponding physiological cross-sectional area (PCSA) were calculated, and force/length muscle relations were found. An in vivo biplanar radiography was performed on five volunteers. The photogrammetric reconstruction of bone axes and landmarks were coupled with a geometric modeling of bones and muscle sites of attachment. Muscular paths were drawn and changes in lengths during movement have been estimated. Directions of muscle forces are the same as that of muscular path at the point of attachment to bone. Magnitudes of muscular forces were found from muscle lengths coupled with force/length relations. Passive forces were directly determined contrary to active muscle forces. A resulting active muscle force is calculated from balancing weight and passive forces at each articular center. Active muscle forces were calculated by distributing the resulting force among active muscles based on the muscular PCSA values.

Tool Profile Modification of Hypoid Gear Machined by Duplex Helical Method

2021 ◽  
Author(s):  
Shunxing Wu ◽  
Hongzhi Yan ◽  
Zhiyong Wang ◽  
Rengui Bi ◽  
Jia Li
Keyword(s):  
Geometric Model ◽  
Tooth Surface ◽  
Gear Pair ◽  
Hypoid Gear ◽  
Tooth Contact Analysis ◽  
Edge Contact ◽  
Profile Modification ◽  
Tool Profile ◽  
Tooth Surfaces ◽  
Loaded Tooth Contact Analysis

Abstract For the hypoid gear pair of the heavy-duty vehicle drive axle machined by the duplex helical method, in order to avoid edge contact and stress concentration on the tooth surface, a four-segment tool profile is designed to modify the concave and convex surfaces simultaneously. First, the geometric model of the four-segment tool profile is established. Second, the mathematical model of the duplex helical method based on the four-segment tool profile is established, and the method of solving the tooth surface generated by the connecting points of the four-segment tool profile is given. Finally, the finite element method of loaded tooth contact analysis is used to analyze the meshing performance of the gear pair obtained by the four-segment tool profile modification, and the results are compared with the original gear pair. The results show that after the tooth surfaces are modified, the edge contact of the tooth surfaces are avoided, the stress distribution of the tooth surfaces are improved, the maximum contact stress of the tooth surfaces are reduced, and the fatigue and wear life of the tooth surface are improved.

scholarly journals Geometric modeling of surfaces dependent cross sections in the tasks of spinning and laying

2019 ◽  
Vol 110 ◽  
pp. 01057
Author(s):  
Yuri Deniskin ◽  
Pavel Miroshnichenko ◽  
Andrew Smolyaninov
Keyword(s):  
Composite Materials ◽  
Cross Sections ◽  
Geometric Modeling ◽  
Geometric Model ◽  
Solid Modeling ◽  
Uniform Method ◽  
Calculation Methods ◽  
Related Process

The article is devoted to the development of a geometric model of surfaces of dependent sections to solve the problems of winding by continuous fibers in the direction of the force and its related process of automated winding of composite materials. A uniform method for specifying the surfaces of dependent sections with a curvilinear generator and a method for solid modeling of the shell obtained by winding or calculation methods are described.

Construction of Receptor Geometric Models for Objects of Complex Technical Forms

2020 ◽  
Vol 7 (4) ◽  
pp. 44-56 ◽  
Author(s):  
Vin Tun E ◽  
Leonid Markin
Keyword(s):  
Solid State ◽  
Geometric Modeling ◽  
Parametric Models ◽  
State Model ◽  
Universal Method ◽  
Receptor Model ◽  
Geometric Models ◽  
Cad System ◽  
Receptor Models ◽  
Single Receptor

In this paper the question related to the use of receptor (voxel) method for geometric modeling to solve practical design problems has been considered. The use of receptor methods is effective in solving a certain class of problems, primarily the problems of automated layout. The complexity of this method’s practical use is due to the fact, that receptor geometric models are never the primary ones. They are formed based on parametric models specified by designer. Receptor models are the internal machine ones. The main problem that prevents the widespread use of the receptor method is the lack of universal methods for converting parametric models into the receptor ones. Available publications show that in solving practical problems various authors have developed their own methods for creating receptor models for objects of "primitives" and "composition of primitives" classes. Therefore, it is extremely urgent to solve the problem of developing a universal method of forming receptor models for objects of complex technical forms. The essence of the proposed method is the transformation of a solid-state model created in a CAD system into a receptor matrix. First in the physical one, in which the solid-state model is discretized into cubes with receptor sizes, and then in the mathematical one — a three-dimensional array with binary codes of zeros and ones. The creation of a physical receptor matrix is carried out by means of the CAD-system itself, allowing diagnose the belonging of a single receptor to a simulated object. The fact of intersection or non-intersection a given position by a single receptor is encoded by "1" and "0" respectively, and this information is transferred to a mathematical receptor model (3-dimensional binary array). This calculation procedure is programmed in the form of a macro, providing a given position of a single receptor and fixing the fact of its intersection with the solid-state model. Have been demonstrated examples for described method’s practical application, and has been carried out CPU time cost estimation for the construction of a physical receptor model depending on the receptor size and object geometric complexity. Actions on data transformation from a solid-state model to a receptor one have been implemented in the form of C# programs.

DESIGN OF A NOVEL STENTED VALVE AND 3D MODELING OF ITS IMPLANTATION IN THE AORTA

2010 ◽  
Vol 22 (02) ◽  
pp. 157-161 ◽  
Author(s):  
Gideon Praveen Kumar ◽  
Lazar Mathew
Keyword(s):  
Aortic Valve ◽  
Left Ventricle ◽  
3D Modeling ◽  
Geometric Modeling ◽  
Geometric Model ◽  
Bioprosthetic Heart Valve ◽  
3D Cad ◽  
Percutaneous Aortic Valve Replacement ◽  
Improved Design ◽  
Valve Model

Objective: To design a novel percutaneous stented valve and model its implantation in the aorta.Background: The dimensions of stented aortic valve components govern its ability to prevent backflow of blood into the left ventricle. Whilst the theoretical parameters for the best stent performance have already been established, an effective valve model and its suitability along with the stent are lacking.Methods: This article discusses the design of a stented valve suitable for percutaneous aortic valve replacement. Steps involved in 3D CAD-based geometric modeling of the stented aortic valve and its implantation in the aorta are presented. Conceptual designing of individual components was used to build the total geometric model.Results: A novel geometric model of percutaneous stented aortic valve was generated. The improved design enhances its performance during and after implantation.Conclusion: The blunt hooks in the stent model prevent its migration in either direction by getting embedded in the aortic endothelium. This novel stent aortic valve may be of great interest to designers of future bioprosthetic heart valve models, as well as to surgeons involved in minimally invasive valve surgeries.

The Undercutting of Circular-Cut Spiral Bevel Gears

1992 ◽  
Vol 114 (2) ◽  
pp. 317-325 ◽  
Author(s):  
Zhang-Hua Fong ◽  
Chung-Biau Tsay
Keyword(s):  
Gear Tooth ◽  
Sufficient Conditions ◽  
Bevel Gear ◽  
Tooth Surface ◽  
Spiral Bevel Gear ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Tooth Surfaces ◽  
Sufficient And Necessary Conditions ◽  
Spiral Bevel

Undercutting is a serious problem in designing spiral bevel gears with small numbers of teeth. Conditions of undercutting for spiral bevel gears vary with the manufacturing methods. Based on the theory of gearing [1], the tooth geometry of the Gleason type circular-cut spiral bevel gear is mathematically modeled. The sufficient and necessary conditions for the existence and regularity of the generated gear tooth surfaces are investigated. The conditions of undercutting for a circular-cut spiral bevel gear are defined by the sufficient conditions of the regular gear tooth surface. The derived undercutting equations can be applicable for checking the undercutting conditions of spiral bevel gears manufactured by the Gleason Duplex Method, Helical Duplex Method, Fixed Setting Method, and Modified Roll Method. An example is included to illustrate the application of the proposed undercut checking equations.

Assistance for Telepresence by Stereovision-Based Augmented Reality and Interactivity in 3D Space

2002 ◽  
Vol 11 (5) ◽  
pp. 525-535 ◽  
Author(s):  
Philippe Fuchs ◽  
Fawzi Nashashibi ◽  
Didier Maman
Keyword(s):  
Image Analysis ◽  
Augmented Reality ◽  
Mixed Reality ◽  
Vision System ◽  
Geometric Model ◽  
Interactive Approach ◽  
3D Space ◽  
Nuclear Plants ◽  
3D Positioning

In this paper, we describe some use of mixed reality as a new assistance for performing teleoperation tasks in remote scenes. We will start by a brief classification of augmented reality. This paper then describes the principle of our mixed reality system in teleoperation. It tackles the problem of scene registration using a man–machine cooperative and multisensory vision system. The system provides the operator with powerful sensorial feedback as well as appropriate tools to build (and update automatically) the geometric model of the perceived scene. We describe a new interactive approach combining image analysis and mixed reality techniques for assisted 3D geometric and semantic modeling. At the end of this paper, we describe applications in nuclear plants with results in 3D positioning.

scholarly journals Meshing principle analysis of 3-DOF involute spherical gear

2020 ◽  
Vol 213 ◽  
pp. 02029
Author(s):  
Baichao Wang ◽  
Xue Zhang ◽  
Litong Zhang ◽  
Xianting Lu
Keyword(s):  
Mathematical Model ◽  
Tooth Profile ◽  
Bevel Gear ◽  
Tooth Surface ◽  
Gear Pair ◽  
Tooth Surfaces ◽  
Three Degree Of Freedom ◽  
Relationship Of ◽  
The Mathematical Model ◽  
Spherical Gear

In this paper, a mathematical model of meshing motion of three degree of freedom involute spherical gear pair is constructed. The mathematical model can realize continuous meshing transmission between gear pairs without transmission principle error. Based on the meshing principle and motion analysis of the gear, the tooth profile of the spherical gear is designed by combining the two tooth surfaces of the involute ring gear and the hemispherical bevel gear. According to the conjugate motion relationship of spherical gear pair, a mathematical model of arc tooth surface of hemispherical bevel gear is established, and the mathematical description of the tooth profile of spherical gear is completed by combining the equation of ring tooth surface. It provides the basis and Reference for the meshing design of ball gear.

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