scholarly journals Influence of Die Threading and Finishing Length in the Thread-Rolling Process Using Flat Dies: A Numerical Analysis

2021 ◽  
Author(s):  
L. Giorleo ◽  
M. Cartapani
Keyword(s):  
Numerical Analysis ◽  
Analytical Method ◽  
Rolling Process ◽  
Die Geometry ◽  
Die Wear ◽  
Geometry Design ◽  
Induced Stress ◽  
Thread Rolling

AbstractIn this paper, a numerical analysis of the cold thread-rolling process using flat dies is presented as a function of the die geometry design. Five die geometries with different threading and finishing ratios were modelled to induce different screw deformation rates. An analytical method was proposed by the authors to design die geometries as a function of screw roll rotation. Screw geometry accuracy, induced stress, and die wear were selected to compare the tested geometries. The results showed that three screw rotations in the threading step were sufficient to guarantee good geometry accuracy. Moreover, the results highlighted that die wear is the most affected parameter among all the tested geometries. Finally, a new solution was proposed by the authors to obtain uniform wear and reduce the die length.

scholarly journals The numerical analysis of the trapezoidal thread rolling process

PAMM ◽  
2007 ◽  
Vol 7 (1) ◽  
pp. 4010027-4010028
Author(s):  
Krzysztof Kukielka ◽  
Leon Kukielka
Keyword(s):  
Numerical Analysis ◽  
Rolling Process ◽  
Thread Rolling

3D Numerical Analysis the State of Elastic/Visco-Plastic Strain in the External Round Thread Rolled on Cold

2014 ◽  
Vol 474 ◽  
pp. 436-441 ◽  
Author(s):  
Krzysztof Kukielka ◽  
Leon Kukielka ◽  
Łukasz Bohdal ◽  
Agnieszka Kułakowska ◽  
Leszek Malag ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Rolling Process ◽  
Nonlinear Phenomena ◽  
Explicit Integration ◽  
Initial Yield Stress ◽  
Discrete Equations ◽  
Hardening Modulus ◽  
Thread Rolling ◽  
Incremental Step

This work describes the thread rolling as a real object and its physical and mathematical modelling. An incremental modelling and numerical solution of the contact problem between movable elastic or rigid tool and elastic/visco-plastic bodies developed in [ is adopted to the numerical simulation of thread rolling process for the case of rigid tool (threading head) and elastic/visco-plastic body (pipe or bar). An update Lagrangian formulation was used to describe nonlinear phenomena on a typical incremental step. For solution of discrete equations of motions and deformations of the object the explicit integration method was applied. The algorithm and application of 3D numerical analysis in ANSYS program were elaborated. This algorithm let for determination of influence of friction coefficient, initial yield stress and plastic hardening modulus. This factors influence will be carried out with 5 levels rotary experiment plan, which let for elaboration of regression equation to describe this relationship. Exemplary results of 3D numerical analysis of displacement and strain in thread for different conditions of rolling process are presented.

Modeling and numerical analysis of the thread rolling process

PAMM ◽  
2006 ◽  
Vol 6 (1) ◽  
pp. 745-746 ◽  
Author(s):  
Krzysztof Kukielka ◽  
Leon Kukielka
Keyword(s):  
Numerical Analysis ◽  
Rolling Process ◽  
Thread Rolling

scholarly journals Numerical Evaluation of Structural Safety of Linear Actuator for Flap Control of Aircraft Based on Airworthiness Standard

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 104
Author(s):  
Dong-Hyeop Kim ◽  
Young-Cheol Kim ◽  
Sang-Woo Kim
Keyword(s):  
Numerical Analysis ◽  
Analytical Method ◽  
Safety Evaluation ◽  
Experimental Tests ◽  
Structural Safety ◽  
Linear Actuator ◽  
The Finite Element Method ◽  
Margin Of Safety ◽  
Verification Methodology ◽  
The Given

Airworthiness standards of Korea recommend verifying structural safety by experimental tests and analytical methods, owing to the development of analysis technology. In this study, we propose a methodology to verify the structural safety of aircraft components based on airworthiness requirements using an analytical method. The structural safety and fatigue integrity of a linear actuator for flap control of aircraft was evaluated through numerical analysis. The static and fatigue analyses for the given loads obtained from the multibody dynamics analysis were performed using the finite element method. Subsequently, the margin of safety and vulnerable area were acquired and the feasibility of the structural safety evaluation using the analytical method was confirmed. The proposed numerical analysis method in this study can be adopted as an analytical verification methodology for the airworthiness standards of civilian aircraft in Korea.

Geometry Design and Contact Ratio Analysis for Circular Arc Parallel-Axis Helical Gears

2016 ◽  
Author(s):  
Z. Chen ◽  
B. Lei ◽  
Q. Zhao
Keyword(s):  
Rolling Process ◽  
Helical Gear ◽  
Space Curve ◽  
Impact Factors ◽  
Contact Ratio ◽  
Circular Arc ◽  
Practical Applications ◽  
Geometry Design ◽  
Gear Mechanism ◽  
The Impact

Based on space curve meshing theory, in this paper, we present a novel geometric design of a circular arc helical gear mechanism for parallel transmission with convex-concave circular arc profiles. The parameter equations describing the contact curves for both the driving gear and the driven gear were deduced from the space curve meshing equations, and parameter equations for calculating the convex-concave circular arc profiles were established both for internal meshing and external meshing. Furthermore, a formula for the contact ratio was deduced, and the impact factors influencing the contact ratio are discussed. Using the deduced equations, several numerical examples were considered to validate the contact ratio equation. The circular arc helical gear mechanism investigated in this study showed a high gear transmission performance when considering practical applications, such as a pure rolling process, a high contact ratio, and a large comprehensive strength.

Study on Heading and Thread-Rolling Processes of Magnesium Alloy Screws

2013 ◽  
Vol 535-536 ◽  
pp. 322-325 ◽  
Author(s):  
Yeong-Maw Hwang ◽  
Kai Neng Hwang ◽  
Chia Yu Chang
Keyword(s):  
Finite Element ◽  
Magnesium Alloy ◽  
Flow Pattern ◽  
Effective Strain ◽  
Metal Flow ◽  
Rolling Process ◽  
Die Set ◽  
Thread Rolling ◽  
Experimental Values ◽  
Two Stages

This study is to investigate the effects of the process parameters on the heading load and metal flow pattern during heading and thread-rolling processes of LZ91 magnesium alloy screws. A heading process composed of two stages is proposed. The material flow pattern of the billet inside the die is analyzed using the finite element analyses. The effects of the upper die velocity, temperatures and friction factors on the heading loads and product quality are discussed. On the other hand, in the thread-rolling process, the effects of the friction factor on the effective stress, effective strain, and tooth height are investigated. Finally, heading and thread-rolling experiments are conducted using a self-designed die set and a lubricant of MoS2. The experimental values are compared with the simulation results to verify the validity of the finite element models and the proposed heading procedures.

scholarly journals Numerical Analysis of a Skew Rolling Process for Producing a Stepped Hollow Shaft Made of Titanium Alloy Ti6Al4V

2016 ◽  
Vol 61 (2) ◽  
pp. 677-682 ◽  
Author(s):  
Z. Pater ◽  
T. Bulzak ◽  
J. Tomczak
Keyword(s):  
Numerical Analysis ◽  
Thickness Distribution ◽  
Effective Strain ◽  
Rolling Process ◽  
Forming Process ◽  
Hollow Shaft ◽  
Wall Thickness Distribution ◽  
Light Trucks ◽  
Titanium Alloy Ti6al4v ◽  
Skew Rolling

Abstract The paper describes a rolling process for a hollow Ti6Al4V alloy shaft used in driving systems of light trucks. The shaft is formed by skew rolling using three tapered rolls. The principle of this forming process was discussed stressing its universality due to the potential of applying it for forming various products by one set of rolls. The numerical analysis results (product shape progression in rolling, wall thickness distribution, effective strain, temperature and variations in loads and torques) confirm that the proposed technique can be used for producing hollow long shafts.

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