The Method of Substitutive Circles Family: Application in Catia Design Environment for Gear Shaped Tool Profiling

2014 ◽  
Vol 1036 ◽  
pp. 370-375 ◽  
Author(s):  
Silviu Berbinschi ◽  
Gabriel Frumuşanu ◽  
Virgil Gabriel Teodor ◽  
Nicolae Oancea
Keyword(s):  
Numerical Data ◽  
Rolling Process ◽  
Design Environment ◽  
Complementary Method ◽  
Contact Points ◽  
Rolling Method ◽  
Graphical Algorithm

Tools which generate by enveloping using the rolling method may be profiled using various methods. The substitutive circles family method is a complementary method developed based a specifically theorem, in which is determined a family of circles associated with the blank’s centrode, family which envelop the profile to be generate. The method assumes the determination of the circles family, transposed in the rolling process between the blank and tool centrodes. In this paper is proposed an algorithm for curling surfaces in enveloping, associated with a pair of rolling circular centrodes. The graphical algorithm is based on the representation of the circles family enveloped the blank’s profile. It is generated the circles family transposed on the centrode associated with the gear shaped cutter and is determined a new position of contact points with the blank. The assembly of these points forms the profile of the gear shaped cutter. The numerical data proof the proposed method quality.

scholarly journals Numerical analysis of a skew rolling process for producing a crankshaft preform

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Konrad Lis ◽  
Łukasz Wójcik ◽  
Zbigniew Pater
Keyword(s):  
Numerical Modeling ◽  
Numerical Analysis ◽  
Cross Section ◽  
Rolling Process ◽  
Damage Function ◽  
New Method ◽  
Rolling Technique ◽  
Rolling Method ◽  
Skew Rolling

Abstract The paper describes a new method for forming a crankshaft preform. The method is based on the skew rolling technique. With this method the part is formed by three tapered rolls rotated with the same velocity and in the same direction. Simultaneously, the rolls either converge or diverge depending on the desired cross section of the product. The numerical modeling enabled determination of the distributions of effective strains, temperatures, and damage function according to the Cockroft - Latham criterion, aswell as variations in the loads and torques during rolling. The results confirm that a crankshaft preform can be formed by the proposed skew rolling method.

scholarly journals Numerical Analysis of the Skew Rolling Process for Rail Axles

2015 ◽  
Vol 60 (1) ◽  
pp. 415-418 ◽  
Author(s):  
Z. Pater ◽  
J. Tomczak ◽  
T. Bulzak
Keyword(s):  
Numerical Modeling ◽  
Effective Strain ◽  
Translational Motion ◽  
Rolling Process ◽  
Simulation Software ◽  
Maximum Diameter ◽  
Cross Sectional ◽  
Rolling Method ◽  
Skew Rolling

Abstract The paper describes a new method for producing stepped rail axles. The method is based on the skew rolling process. With this method, the product is formed by three tapered rolls located every 120° on the perimeter of the billet. Positioned askew to the centerline of the billet, the rolls rotate in the same direction and with the same velocity. At the same time, they get closer together or go apart depending on the desired cross sectional reduction of an axle step. In addition, the workpiece is shifted lengthwise relative to the rolls by the translational motion of the workpiece-holding chuck. In order to verify the designed method for producing rail axles, a series of numerical simulations were performed using the Simufact. Forming v.12 simulation software. The numerical modeling enabled the determination of maps of the effective strain and temperature in the finished product as well as variations in the loads and torques during rolling. The numerical results unambiguously confirm that the skew rolling method can be applied to form parts of considerable dimensions (the modeled axles had a length of 2146 mm and their maximum diameter was 202 mm).

scholarly journals The Effect of Process Parameters in Helical Rolling of Balls on the Quality of Products and the Forming Process

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2125 ◽  
Author(s):  
Janusz Tomczak ◽  
Zbigniew Pater ◽  
Tomasz Bulzak
Keyword(s):  
Metal Flow ◽  
Experimental Tests ◽  
Rolling Process ◽  
Helical Rolling ◽  
Forming Process ◽  
University Of Technology ◽  
Quality Of Products ◽  
Skew Rolling

This paper presents selected numerical and experimental results of a skew rolling process for producing balls using helical tools. The study investigates the effect of the billet’s initial temperature on the quality of produced balls and the rolling process itself. In addition, the effect of billet diameter on the quality of produced balls is investigated. Experimental tests were performed using a helical rolling mill available at the Lublin University of Technology. The experiments consisted of rolling 40 mm diameter balls with the use of two helical tools. To determine optimal rolling parameters ensuring the highest quality of produced balls, numerical modelling was performed using the finite element method in the Forge software. The numerical analysis involved the determination of metal flow kinematics, temperature and damage criterion distributions, as well as the measurement of variations in the force parameters. The results demonstrate that the highest quality balls are produced from billet preheated to approximately 1000 °C.

Parameter Study of Offset Press Cylinder Based on Sliding Friction

2010 ◽  
Vol 174 ◽  
pp. 299-302 ◽  
Author(s):  
Hai Yan Zhang ◽  
He Ping Hou ◽  
Jun Feng Si ◽  
Xiao Yu Chen
Keyword(s):  
Contact Area ◽  
Sliding Friction ◽  
Accurate Determination ◽  
Rolling Process ◽  
Elastic Cylinder ◽  
Parameter Study ◽  
Cylinder Radius ◽  
Printing Quality ◽  
Dot Gain

In the contact area of offset, a relative slide occurs between the surface of plate cylinder and blanket cylinder, which changes the print image and influences the printing quality. The relative slide in the cylinders’ rolling process is investigated, and the determination rule of cylinders’ geometric parameters of offset press is proposed. The results show that the relative slide is minimization under the condition that the compression of elastic cylinder radius is 0.2 times bigger than that of rigid cylinder radius, and the deformation of print image and dot gain both are minimization. The results provide theoretical direction for accurate determination of cylinder radius of offset press.

On Flapping Flight of Aeroplanes

1899 ◽  
Vol 3 (11) ◽  
pp. 59-65
Author(s):  
Maurice F. Fitz–Gerald
Keyword(s):  
Numerical Data ◽  
Flapping Flight ◽  
Air Pressure ◽  
Supporting Force

It has been long known, principally through experiments on soaring, that a large, if not by far the largest, part of the supporting force obtained by birds in regular flight, is probably furnished by upward air pressure on their wings, regarded as planes moving horizontally, with their surfaces slightly inclined to the direction of motion.Langley's “Experiments on Aero–dynamics” furnish some numerical data for estimating the power required to sustain an aeroplane of given weight, propelled horizontally by a known force, and he applies these to the determination of the problem whether this could be effected by screw propellers, analogous to those of a ship, actuated by machinery of existing type.

Determination of contact points between workpiece and fixture elements as a tool for augmented reality in fixture design

2019 ◽  
Author(s):  
Vitalii Ivanov ◽  
Ivan Pavlenko ◽  
Oleksandr Liaposhchenko ◽  
Oleksandr Gusak ◽  
Vita Pavlenko
Keyword(s):  
Augmented Reality ◽  
Fixture Design ◽  
Contact Points

Characteristics of a Self-Lubricated Stepped Thrust Pad of Infinite Width With Compressible Lubricant

1959 ◽  
Vol 81 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Kikuo C. Kochi
Keyword(s):  
Optimum Design ◽  
Practical Interest ◽  
Numerical Data ◽  
Numerical Results ◽  
Design Parameters ◽  
Analytic Expressions ◽  
Thrust Pad ◽  
Compressible Lubricant

Harrison’s equation for the pressure in a gas-lubricated bearing of infinite width is solved for a thrust pad with stepped configuration. Analytic expressions for the pressure and load are developed. Numerical results are presented graphically. The analytic expressions together with the numerical data permit most of those characteristics of the stepped pad of practical interest to be completely determinable. Determination of optimum design parameters is given by a pair of graphs.

Determination of Thermal Parameters of a Work-Roll in Warm Rolling Using Inverse Modeling

2018 ◽  
Author(s):  
Vinod Yadav
Keyword(s):  
Inverse Method ◽  
Work Roll ◽  
Rolling Process ◽  
Thermal Parameters ◽  
Shop Floor ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Convective Heat Transfer Coefficients ◽  
Work Rolls

Thermal parameters of a work-roll play an important role in the modeling of the rolling process, due to periodic thermal loading. The knowledge of thermal parameters is also vital in understanding the fatigue life of the work-roll and the thermal crown. However, estimation of the thermal parameters viz., thermal conductivity, thermal diffusivity and convective heat transfer coefficients at both, inner and outer roll periphery is tough to realize during the rolling process. Various methods employed earlier for measuring the thermal properties of work-rolls in the rolling process requires intrusion in the surface of the work-rolls, mainly to embed the thermocouples inside the rolls. These methods are easy to implement, but it is really hard to achieve truthful estimation. A possible way out is to measure the average thermal parameters of a work roll in the rolling process by utilizing the measured temperature at two specified locations on the work-roll surface. In this work, an inverse method is proposed to estimate the thermal properties and convective heat transfer coefficients of a roll in the rolling process. The inverse method makes use of a direct model of temperature determination considering plane strain problem, which is based on the integral transform method. For minimizing the error between the computed and experimentally recorded data, a quasi-Newton method is used. In lieu of shop floor experiments, a finite element method (FEM) based package ABAQUS 6.10 is used to obtain the temperature distribution in the work-roll. Further, an additive white Gaussian error is added in the FEM simulated measurements to assess the inverse method for stability towards mild measurements. The inverse estimation is successfully validated and can be used in shop floor for the online determination of thermal parameters of the work-rolls in the rolling process.

Consideration of the Torsional Stiffness in Hollow-Core Slabs’ Design

2019 ◽  
Vol 968 ◽  
pp. 330-341
Author(s):  
Talyat Azizov ◽  
Wit Derkowski ◽  
Nadzieja Jurkowska
Keyword(s):  
Finite Elements ◽  
Precast Concrete ◽  
Numerical Data ◽  
Torsional Stiffness ◽  
System Of Equations ◽  
Hollow Core ◽  
Floor Slabs ◽  
Formation Of Cracks ◽  
Resolving System

The paper discusses the principles of precast concrete hollow-core slabs taking into account their spatial work. It is shown that consideration of spatial work makes it possible to determine the forces in individual floor slabs significantly more precise. The fact that strain redistribution between precast floor slabs depends on slabs’ bending and torsional stiffness is shown. The research has been mostly devoted to determination of the bending stiffness with regard to formation of cracks and the change in torsional stiffness, especially considering the presence of normal cracks, which is still unstudied. This paper presents the technique for determining the torsional stiffness of hollow-core slabs with normal cracks. In order to determine the components included in the resolving system of equations, it is proposed to use an approximation method based on the processing of numerical data using spatial finite elements.

Computer-aided determination of occlusal contact points for dental 3-D CAD

2006 ◽  
Vol 44 (5) ◽  
pp. 445-450 ◽  
Author(s):  
Tomoaki Maruyama ◽  
Yasuo Nakamura ◽  
Toyohiko Hayashi ◽  
Kazumasa Kato
Keyword(s):  
Occlusal Contact ◽  
Contact Points ◽  
Computer Aided
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