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

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.

2015 ◽  
Vol 60 (1) ◽  
pp. 415-418 ◽  
Author(s):  
Z. Pater ◽  
J. Tomczak ◽  
T. Bulzak

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).


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 764
Author(s):  
Jarosław Bartnicki ◽  
Yingxiang Xia ◽  
Xuedao Shu

The paper presents chosen aspects of the skew rolling process of hollow stepped products with the use of a skew rolling mill designed and manufactured at the Lublin University of Technology. This machine is characterized by the numerical control of spacing between the working rolls and the sequence of the gripper axial movement, which allows for the individual programming of the obtained shapes of parts such as stepped axles and shafts. The length of these zones and the values of possibly realizable cross-section reduction and obtained outlines are the subject of this research paper. The chosen results regarding the influence of the technological parameters used on the course of the process are shown in the present study. Numerical modelling using the finite element method in Simufact Forming, as well as the results of experimental tests performed in a skew rolling mill, were applied in the conducted research. The work takes into account the influence of cross-section reduction of the hollow parts and the feed rate per rotation on the metal flow mechanisms in the skew rolling process. The presented results concern the obtained dimensional deviations and changes in the wall thickness determining the proper choice of technological parameters for hollow parts formed by the skew rolling method. Knowledge about the cause of the occurrence of these limitations is very important for the development of this technology and the choice of the process parameters.


Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2125 ◽  
Author(s):  
Janusz Tomczak ◽  
Zbigniew Pater ◽  
Tomasz Bulzak

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.


Author(s):  
M. I. Epov ◽  
◽  
V. N. Glinskikh ◽  
M. N. Nikitenko ◽  
K. V. Sukhorukova ◽  
...  

The work is devoted to the substantiation of new geophysical technology for mapping the Bazhenovskaya Formation based on an impulsive electromagnetic sounding from wells. Theoretically shown the possibility of its application to study the formation from highly inclined and subhorizontal wells drilled in the Upper and Middle Jurassic formations. Numerical modeling of the signals in realistic geoelectric models of the Bazhenov Formation with real well trajectories is carried out on the example of the East Surgut field. The calculations have established that the determination of spatial locations of the top and bottom of the beds is possible when using different-length sondes. Zones of high sensitivity of the full magnetic field matrix to the boundaries with a sufficient signal level at considerable distance, even with a small sonde length, are determined. It is theoretically established that pulsed sounding of the Bazhenov Formation from the Upper and Middle Jurassic reservoirs is feasible for both mapping the boundaries of the formation and tracing its lateral variability.


2014 ◽  
Vol 1036 ◽  
pp. 370-375 ◽  
Author(s):  
Silviu Berbinschi ◽  
Gabriel Frumuşanu ◽  
Virgil Gabriel Teodor ◽  
Nicolae Oancea

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.


2016 ◽  
Vol 61 (2) ◽  
pp. 677-682 ◽  
Author(s):  
Z. Pater ◽  
T. Bulzak ◽  
J. Tomczak

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.


2016 ◽  
Vol 10 (32) ◽  
pp. 124-131 ◽  
Author(s):  
Tomasz Bulzak ◽  
Zbigniew Pater ◽  
Janusz Tomczak

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Janusz Tomczak ◽  
Zbigniew Pater ◽  
Tomasz Bulzak ◽  
Konrad Lis ◽  
Tomasz Kusiak ◽  
...  

AbstractResults of a study investigating a skew rolling process for elongated axisymmetric parts are presented. Despite the fact that the skew rolling technique for producing such parts was developed and implemented in the mid-twentieth century, there are no studies on this problem. The first part of this paper presents the results of FEM modelling of skew rolling stepped axles and shafts (solid and hollow). The FEM analysis was performed using the MSC Simufact Forming software. The numerical simulation involved the determination of metal flow patterns, the analysis of thermal parameters of the material during rolling, and the prediction of cracking by the Cockcroft-Latham ductile fracture criterion. Force parameters of rolling solid and hollow parts were also determined. The aim of the FEM analysis was to determine initial design assumptions and parameters for the development of the skew rolling mill. Later on in the paper, a design solution of a CNC skew rolling mill for rolling parts based on their envelope profile is proposed. FEM strength test results of a mill stand, obtained with MSC. NASTRAN, are presented. Finally, the performance test results of the constructed rolling mill are presented. The experiments involved rolling real stepped shafts that were modelled numerically. Obtained results show that the proposed skew rolling method has considerable potential. The designed and constructed rolling mill can be used to perform the rolling process according to the proposed method, with the tool and material kinematics being controlled based on the set parameters of a workpiece envelope.


2014 ◽  
Vol 474 ◽  
pp. 436-441 ◽  
Author(s):  
Krzysztof Kukielka ◽  
Leon Kukielka ◽  
Łukasz Bohdal ◽  
Agnieszka Kułakowska ◽  
Leszek Malag ◽  
...  

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.


2013 ◽  
Vol 58 (4) ◽  
pp. 1071-1076 ◽  
Author(s):  
J. Tomczak ◽  
Z. Pater ◽  
J. Bartnicki

Abstract This paper presents results of theoretical and experimental research on skew rolling process of balls with diameter ;30 mm in multiple helical tools. Numerical analysis of the process was conducted basing on finite element method (FEM), using the commercial software Simufact Forming in version 10.0. Simulations were made in the three-dimensional state of strain with consideration of complex thermal analysis, due to which progression of the products shape was determined. Distributions of strains and temperatures as well as the process force parameters were also determined. The results of numerical calculations were experimentally verified in laboratory conditions. The obtained results confirmed the possibility of semi-finished products of balls type manufacturing by means of rolling in multiple helical impressions.


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