The Rolling Forming Principle and the Deformation Analysis of the Ring Multi-Mandrel Roller

2012 ◽  
Vol 502 ◽  
pp. 392-396
Author(s):  
Hong Li ◽  
Kun Ju Bai
Keyword(s):  
Research Result ◽  
Radial Strain ◽  
Mechanical Analysis ◽  
Ring Rolling ◽  
Deformation Analysis ◽  
Deformation Model ◽  
Technological Parameters ◽  
Tangential Strain ◽  
Mathematical Expressions ◽  
Cold Ring Rolling

this paper, focusing on the actuality and the features of the cold ring rolling, studies the forming principle of the rolling of multi-mandrel roller. Through the kinematics analysis of the rolling of ring multi-mandrel roller, the deformation simulation and the mechanical analysis of the infinitesimal gridding strain, this paper builds the infinitesimal deformation model of ring blank’s cold rolling, analyzes the deformation rules of the ring blank’s thickness direction rolled by the multi-mandrel roller and the relation between the tangential strain and the radial strain which should be satisfied by the mandrel roller’s movement values, and deduces out the mathematical expressions of the needed technological parameters like the minimum instantaneous rolling reduction. The research result can be used as the theoretical foundations for designing the multi-mandrel rolling miss and working out the rolling technology of the ring multi-mandrel roller.

scholarly journals Left ventricular and left atrial deformation imaging early after pPCI: does diabetes mellitus make any difference?

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
D Trifunovic Zamaklar ◽  
G Krljanac ◽  
M Asanin ◽  
L Savic-Spasic ◽  
J Vratonjic ◽  
...  
Keyword(s):  
Heart Failure ◽  
Strain Rate ◽  
Myocardial Function ◽  
Radial Strain ◽  
Left Ventricular ◽  
Deformation Analysis ◽  
Syntax Score ◽  
Deformation Imaging ◽  
Early Diastole

Abstract Funding Acknowledgements Type of funding sources: None. onbehalf PREDICT-VT More extensive coronary atherosclerosis in diabetes mellitu (DM) induces poorer clinical outcomes after STEMI, but there are data suggesting that impaired myocardial function in DM, even independently from epicardial coronary lesions severity, might have detrimental effect, predominately on heart failure development in DM. Aim the current study is a sub-study of PREDICT-VT study (NCT03263949), aimed to analyse LV and LA function using myocardial deformation imaging based on speckle tracking echocardiography after pPCI in STEMI patients with and without DM. Methods in 307 consecutive pts enrolled in PREDICT-VT study early echocardiography (5 ± 2 days after pPCI) was done including LA and multilayer LV deformation analysis with longitudinal (L), radial (R) and circumferential (C) strain (S; %) and strain rate (SR, 1/sec), LV index of post systolic shortening for longitudinal (PSS LS) and circumferential (PSS CS) strains and analysis of LV rotation mechanic. Results from 242 patients who completed 1 year follow up, 48 (20%) had DM. Pts with DM were older (60 ± 1,01 vs 57 ± 10; p = 0.067) and had insignificantly higher SYNTAX score (18.5 ± 9.2 vs 15.8 ± 9.8, p = 0.118) . However, diabetics had more severely impaired EF (44.2 ± 8.6 vs 49.2 ± 9.8, p = 0.001), E/A ratio (0.78 ± 0.33 vs 0.90 ± 0.34; p = 0.036) and MAPSE (1.18 ± 0.32 vs 1.32 ± 0.33; p = 0.001).  Global LV LS on all layers (endo: -13.6 ± 4.0 vs-16.2 ± 4.7; mid: -11.9 ± 3.5 vs -14.1 ± 4.1; epi: -10.4 ± 3.1 vs -12.3 ± 3.6; p < 0.005 for all) was impaired in DM patients, as well as longitudinal systolic SR (-0.71 ± 0.23 vs -0.84 ± 0.24; p = 0.001) and SR during early diastole (0.65 ± 0.26 vs 0.83 ± 0.33, p < 0.001). Patients with DM had more pronounced longitudinal posts-systolic shortening throughout LV wall (endo: 21.4 ± 16.1 vs 13.7 ± 13.3, p = 0.005; mid: 21.9 ± 16.1 vs 14.3 ± 13.1, p = 0.006; epi: 22.4 ± 16.5 vs 15.3 ± 13.7, p = 0.010) and higher LV mechanical dispersion (MDI: 71.3 ± 38.3 vs 59.0 ± 18.9, p = 0.037). LA strain was significantly impaired in DM patients (18.9 ± 7.7 vs 22.6 ± 10.0, p = 0.011) and even more profoundly LA strain rate during early diastole (-0.73 ± 0.48 vs -1.00 ±0.58, p = 0.002). Patients with DM also had more impaired LV global (15.7 ± 9.1 vs 19.8 ± 10.4, p = 0.013) radial strain, global LV circumferencial strain, especially at the mid-wall level (-13.9 ± 4.2 vs -16.0 ± 4.3, p = 0.005) and impaired circumferential SR E (1.25± 0.44 vs 1.49 ± 0.46, p = 0.003). End-systolic rotation of the LV apex was more impaired in DM (4.7 ± 5.1 vs 6.8 ± 5.5, p= 0.022). During 1 year follow-up heart failure and all-cause mortality tend to be higher among DM pts (46.7% vs 35.2%, p = 0.153). Conclusion STEMI patients with DM have more severely impaired LV systolic and diastolic function estimated both by traditional parameter and advanced echo techniques. These results might, at least partially, explain why outcomes after STEMI in DM might be poorer, even in the absence of more complex angiographic findings, pointing to the significance of impaired myocardial function DM itself.

The effect of cold ring rolling on the evolution of microstructure and texture in 100Cr6 steel

2010 ◽  
Vol 527 (9) ◽  
pp. 2431-2436 ◽  
Author(s):  
K. Ryttberg ◽  
M. Knutson Wedel ◽  
V. Recina ◽  
P. Dahlman ◽  
L. Nyborg
Keyword(s):  
Ring Rolling ◽  
Cold Ring Rolling ◽  
Evolution Of Microstructure

scholarly journals Mechanical analysis of sealing performance for compression packer rubber tube

2018 ◽  
Vol 19 (3) ◽  
pp. 309 ◽  
Author(s):  
Fuying Zhang ◽  
Xiangmin Jiang ◽  
Honghao Wang ◽  
Nana Song ◽  
Jianlei Chen ◽  
...  
Keyword(s):  
Structural Design ◽  
Mechanical Analysis ◽  
Deformation Analysis ◽  
Rubber Tube ◽  
Support Ring ◽  
Sealing Performance ◽  
Deformation Stages ◽  
Core Components ◽  
Sealing Mechanism ◽  
Sealing Pressure

The compression packer rubber is one of the core components of the packer. According to the sealing mechanism of the compression packers rubber, the deformation of rubber between the central tube and casing tube is analyzed in the initial and working stages. The compression rubber is also strained radially against the support ring by means of a controlled tubular expansion process. In this paper, the theoretical model for the deformation analysis is established by the structure and working characteristics of rubber tube. In addition, the nonlinear relationship between the material, geometry and stress in the constrained and stable deformation stages is analyzed by application of pressure methods. The analytical results show the contact pressure and shear stress distribution on the sealing surface of the rubber and the effect of rubber geometry and its material properties on sealing performance in terms of maximum sealing pressure. Then, the criterion of sealing performance evaluation of the rubber is established by the numerical results. This analytical model will provide a theoretical basis and guidance for the structural design of the compression packer rubber and it will be of great significance to improve the sealing performance and reliability of packer rubber.

scholarly journals Research of the hydraulic resistance of the granular filter of the sweeping mashnine

2019 ◽  
Vol 135 ◽  
pp. 01049
Author(s):  
Rashid Sharapov
Keyword(s):  
Hydraulic Resistance ◽  
Experimental Studies ◽  
Air Purification ◽  
Technological Parameters ◽  
Variable Parameters ◽  
Granular Filter ◽  
Modern Cities ◽  
Mathematical Expressions ◽  
Cleaning Equipment ◽  
Analytical Expressions

The article focuses on the need to improve the ecology in modern cities based on the development of new cleaning equipment. It is proposed to use a granular filter as a dust cleaning unit in sweeping machines. The advantages of granular filters over other types of filtering apparatus are given. The basic schemes of working equipment of sweepers are considered. To describe the processes during air purification in the proposed granular filter, mathematical expressions are proposed to determine the hydraulic resistance of the proposed filter. When developing analytical expressions, the structural and technological features of the proposed filter were taken into account. The results of calculating the hydraulic resistance of the proposed granular filter depending on its main structural and technological parameters are obtained. To confirm the obtained analytical expressions, experimental studies were carried out. The clinker of the Belgorod cement plant of a fraction of -10 + 5 mm was selected as the filtering material. During the experiment, cement was used as dust with a specific surface of various dispersion, determined by the parameter δ50. In addition, filtering speed and filtering time are accepted as variable parameters.

Investigation on Constant and Variable Feed Speeds Effects in Ring Rolling Process Using 3D FEM

2011 ◽  
Vol 264-265 ◽  
pp. 1776-1781 ◽  
Author(s):  
Nassir Anjami ◽  
Ali Basti
Keyword(s):  
Finite Element ◽  
Rolling Process ◽  
Ring Rolling ◽  
Outer Diameter ◽  
Fe Model ◽  
Feed Speed ◽  
3D Fem ◽  
Cold Ring Rolling ◽  
Plastic Deformation Behavior ◽  
Ring Rolling Process

Although cold ring rolling (CRR) process is largely used in the manufacturing of profiled rings like bearing races, research on this purpose has been scant. In this study, based on a validated finite element (FE) model, CRR process is simulated regarding the variable and constant feed speeds of the mandrel roll which lead to constant and variable values of the ring's diameter growth rates respectively using a 3D rigid-plastic finite element method (FEM). Major technological problems involved in the process including plastic deformation behavior, strain distribution and its uniformity, Cockcroft and Latham damage field and final outer diameter of ring are fully investigated. The results of simulations would provide a good basis for process control especially feed speed controlled mills and guiding the design and optimization of both cold and hot ring rolling process.

Researches on the Ring Stiffness Condition in Cold Ring Rolling

2011 ◽  
Vol 291-294 ◽  
pp. 297-305
Author(s):  
Li Bo Pan ◽  
Lin Hua ◽  
Dong Sheng Qian
Keyword(s):  
Mechanical Model ◽  
Position Angle ◽  
Rolling Process ◽  
Ring Rolling ◽  
Advanced Manufacturing Technology ◽  
Advanced Manufacturing ◽  
Simulation Experiments ◽  
Element Simulation ◽  
Cold Ring Rolling ◽  
Ring Blank

Cold ring rolling is a kind of advanced manufacturing technology. During rolling process the ring may be collapsed or deformed unexpectedly under the pressure of guide roll because the stiffness condition is not met. The force of guide roll to ring was obtained by analyzing the forces to ring. The stiffness condition expressions of ring during rolling were shown after constructing the mechanical model. According to the expressions, the effects of several parameters on the stiffness condition were discussed and analyzed in detail, such as position angle of guide roll, friction coefficient and feed rate, etc, which revealed essential reasons of some cases occurring in cold ring rolling. Then the ring blank dimension was deduced based on the ring stiffness condition. The dimensions of ring blank should meet a relationship to ensure the ring stiffness condition to be satisfied during rolling, which can conduct the practical manufacturing effectively. Finally the analysis and effect laws were proved by finite element simulation experiments. The researches could be helpful to control parameter in cold ring rolling effectively for high quality products.

Determining and Optimizing of Guide Rolls Motion Track in Cold Ring Rolling Process

2006 ◽  
Vol 532-533 ◽  
pp. 141-144 ◽  
Author(s):  
Zhi Chao Sun ◽  
He Yang ◽  
Lan Yun Li
Keyword(s):  
Functional Relationship ◽  
Rolling Force ◽  
Rolling Process ◽  
Initial Position ◽  
Ring Rolling ◽  
Software Environment ◽  
Cold Ring Rolling ◽  
The Stability ◽  
Ring Rolling Process ◽  
And Control

Guide rolls play an important role in controlling both the ring circularity and the stability of cold ring rolling process. However, it is difficult to predict and control the motion of the guide rolls due to the complexity of process associated with the coupled effects of multi-factors. In this paper, a reasonable controlling model of the guide rolls is proposed, and the functional relationship between the motion track of the guide rolls and their setup parameters and process ones is established, by which the guide rolls motion track can be determined. On this basis, a 3D-FE simulation model for cold ring rolling is developed under the ABAQUS software environment and the effects of the initial position and motion track of the guide rolls on the forming stability, ring circularity, rolling force, and oscillating are investigated. Taking the forming stability and ring circularity as objects, the optimum initial position and motion track of the guide rolls are obtained.

scholarly journals Using Bayesian methods for the parameter estimation of deformation monitoring networks

2008 ◽  
Vol 8 (2) ◽  
pp. 335-347 ◽  
Author(s):  
E. Tanir ◽  
K. Felsenstein ◽  
M. Yalcinkaya
Keyword(s):  
Parameter Estimation ◽  
Prior Information ◽  
Likelihood Function ◽  
Deformation Monitoring ◽  
Point Of View ◽  
Deformation Analysis ◽  
Landslide Monitoring ◽  
Deformation Model ◽  
Additional Parameter ◽  
Monitoring Networks

Abstract. In order to investigate the deformations of an area or an object, geodetic observations are repeated at different time epochs and then these observations of each period are adjusted independently. From the coordinate differences between the epochs the input parameters of a deformation model are estimated. The decision about the deformation is given by appropriate models using the parameter estimation results from each observation period. So, we have to be sure that we use accurately taken observations (assessing the quality of observations) and that we also use an appropriate mathematical model for both adjustment of period measurements and for the deformation modelling (Caspary, 2000). All inaccuracies of the model, especially systematic and gross errors in the observations, as well as incorrectly evaluated a priori variances will contaminate the results and lead to apparent deformations. Therefore, it is of prime importance to employ all known methods which can contribute to the development of a realistic model. In Albertella et al. (2005), a new testing procedure from Bayesian point of view in deformation analysis was developed by taking into consideration prior information about the displacements in case estimated displacements are small w.r.t. (with respect to) measurement precision. Within our study, we want to introduce additional parameter estimation from the Bayesian point of view for a deformation monitoring network which is constructed for landslide monitoring in Macka in the province of Trabzon in north eastern Turkey. We used LSQ parameter estimation results to set up prior information for this additional parameter estimation procedure. The Bayesian inference allows evaluating the probability of an event by available prior evidences and collected observations. Bayes theorem underlines that the observations modify through the likelihood function the prior knowledge of the parameters, thus leading to the posterior density function of the parameters themselves.

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