Shell Body Nose Forming by Rotary Swaging Process

2011 ◽  
Vol 213 ◽  
pp. 221-225 ◽  
Author(s):  
Jeong Hwan Jang ◽  
Byeong Don Joo ◽  
Sung Min Mun ◽  
Young Hoon Moon
Keyword(s):  
Finite Element ◽  
Initial Thickness ◽  
Dimensional Changes ◽  
Rotary Swaging ◽  
Inside Diameter ◽  
Before And After ◽  
Forming Characteristics ◽  
Inner Diameter ◽  
The Given ◽  
Diameter Reduction

Studies on the forming characteristics by a rotary swaging process using the sub-scale specimens have been carried out to obtain a shell body nose of desirable quality. To analyze the changes of the nose thickness and length at the respective reduction of inside diameter, the finite element simulations were carried out. As a result, the desired target dimension is satisfied with the diameter reduction of more than 64 % for the given preform. The thickness of nose area increased up to 56.1 % from initial thickness of 2.62 mm to 4.09 mm after swaging. The values of the hardness before and after swaging were 208 HV and 325 HV, respectively. To analyze the dimensional changes (length and thickness) of nose area with decreasing inside diameter, the rotary swaging test was carried out for two different diameter reductions such as 65 % and 67 %. The lengths of nose area for the diameter reductions are 11.79 mm in 65 % and 12.53 mm in 67 %, respectively. At the diameter reduction of more than 67%, the crack occurs when the localized strain hardening reduces ductility in internal area. Therefore, the nose area should be formed from 64% to 67% reduction in target inner diameter.

Dimensional Changes in Tube Swaging

1966 ◽  
Vol 88 (2) ◽  
pp. 147-150 ◽  
Author(s):  
Serope Kalpakjian
Keyword(s):  
Wall Thickness ◽  
Appreciable Effect ◽  
Process Variables ◽  
Workpiece Material ◽  
Thickness Increase ◽  
Dimensional Changes ◽  
Independent Variables ◽  
Rotary Swaging ◽  
Diameter Reduction ◽  
Wall Thickness Increase

The purpose of this study was to investigate changes in the wall thickness of tubes sunk by the rotary swaging process. The independent variables were: Workpiece material, original wall thickness of tube, die angle, die overgrind, and diameter reduction. The results indicated that of these five variables only the diameter reduction was a factor in wall-thickness increase. Material and other process variables did not appear to have appreciable effect within the range studied.

scholarly journals Finite element 3D numerical simulation study of car braking systems and brake disc/drum – pad/shoe friction couple materials

2020 ◽  
Vol 180 ◽  
pp. 03003
Author(s):  
George Ipate ◽  
Filip Ilie ◽  
Andreea Catalina Cristescu
Keyword(s):  
Finite Element ◽  
Geometric Model ◽  
Structural Deformation ◽  
Outer Side ◽  
Brake Disc ◽  
Outer Diameter ◽  
Stick Slip ◽  
Inner Diameter ◽  
3D Geometric Model ◽  
The Given

Our study uses the finite element method of modeling and analyzing the functioning of a braking system for a modern vehicle, in terms of stress ditributions, structural deformation, wear and thermal gradient of the brake disc and drum. The 3D geometric model of system brake is designed using Solidworks, and the coupled thermal and structural analysis is performed with the ANSYS Workbench R16 program. The brake was applied when the car was 85.7 km / h (ω = 125 rad · s-1), the duration of braking until the car stopped was t = 5 s. For the given example, the coefficient of average friction during braking, considering the pressure on the pad p = 7.5 MPa, is μ = 0.35. It was discovered that the relative deformations of the plate and disc are larger in the area of the outer diameter than that of the inner diameter. This is also outlined by the fact that the pressure is higher on the outer sides than on the inner sides of the plate, the highest value being in the central axis zone of the outer side. Knowing the thermophysical characteristics of the disc and the plate and the working conditions, it was possible to determine the temperature variation during braking. The results of the numerical research revealed that an increase of the contact pressure and / or the relative speed between the contact surfaces implies an increase of the amplitude of the stick-slip phenomenon.

Heat Power Determination of Dv-290 Refrigerator’s Evaporator on the Basis of Thermodynamic Parameters of Inlet Air / Określenie Mocy Cieplnej Parownika Chłodziarki Dv-290 Na Podstawie Parametrów Termodynamicznych Powietrza Wlotowego

2012 ◽  
Vol 57 (4) ◽  
pp. 911-920
Author(s):  
Bernard Nowak ◽  
Zbigniew Kuczera
Keyword(s):  
Thermodynamic Parameters ◽  
Thermal Power ◽  
Correlation Coefficients ◽  
Specific Humidity ◽  
Physical Parameters ◽  
Air Cooling ◽  
Regression Equations ◽  
Evaporation And Condensation ◽  
Before And After ◽  
The Given

Abstract The present paper introduces a method for calculating the thermal power of DV-290 mining air cooler’s evaporator. The power usually differs from the nominal power given by the manufacturer. The thermodynamic parameters of cooled air are not obtained as a result of in situ measurements, but in indirect manner that is by determining the evaporation and condensation’s pressure values of R407C refrigerant. The pressure dependencies formulated as a function of air enthalpy at the evaporator’s inlet were obtained using calculations of a computer program which solves the system of equations describing heat and mass transfer in the refrigerator’s compressor on the basis of previous measurements of air performed before and after its cooling. The obtained dependencies are demonstrated in a graphical (fig. 2 and fig. 3) and analytical (the regression equations (19) and (20)) manner, the values of correlation coefficients are also presented. For the known evaporation and condensation pressure values of the refrigerant, and thus for its basic physical parameters the complete thermal power of the evaporator was determined, that is its: air cooling overt power, dehumidification occult power, temperature, relative humidity and specific humidity of air after its cooling. In addition, using the mentioned method, the capacity of DV-290 refrigerator’s evaporator is provided for the given thermodynamic parameters of air before cooling, along with air thermodynamic parameters after cooling.

Three-dimensional changes in root angulation of buccal versus palatal maxillary impacted canines after orthodontic traction: A retrospective before and after study

2021 ◽  
Author(s):  
Yalil Augusto Rodríguez-Cárdenas ◽  
Luis Ernesto Arriola-Guillén ◽  
Aron Aliaga-Del Castillo ◽  
Gustavo Armando Ruíz-Mora ◽  
Guilherme Janson ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Dimensional Changes ◽  
Impacted Canines ◽  
Before And After ◽  
Before And After Study

Weight-Reduction Optimization Design for Milling Planer Bed Based on Finite Element Analysis

2012 ◽  
Vol 490-495 ◽  
pp. 2785-2789
Author(s):  
Dong Sun ◽  
Xu Dong Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Weight Reduction ◽  
Optimization Design ◽  
Weak Link ◽  
Three Dimensional ◽  
Production Costs ◽  
Element Analysis ◽  
Before And After ◽  
Improvement Scheme

The milling planer bed is one of the most important foundational parts for the entire machine, sufficient stiffness is required. The posterior segment of a certain milling planer bed is regarded as the optimization object in this paper. Three-dimensional modeling method is used to calculate the exact weight of the bed and then finite element analysis is used to research the static and dynamic characteristics before and after weight-reduction. The weak link of the bed is found out and a improvement scheme is put forward ensuring lower production costs under the premise of sufficient rigidity.

POLICY OF PROMOTING ALCOHOL CONSUMPTION IN TIMES OF COVID-19 LOCKDOWN IN INDIA: A MEDICAL AND CONSTITUTIONAL ANALYSIS.

2021 ◽  
pp. 21-24
Author(s):  
Neha Sharma ◽  
Ayush Anand ◽  
Shreyas Joshi ◽  
Samrat Ray
Keyword(s):  
Mobile Application ◽  
Prospective Observational Study ◽  
Social Contact ◽  
Contact Tracing ◽  
Family Welfare ◽  
Cumulative Number ◽  
Test Results ◽  
Before And After ◽  
The Given ◽  
Constitutional Analysis

BACKGROUND: India, with the declaration of COVID-19 as a pandemic, started imposing restrictions in the country th and initiated a nationwide lockdown under Section 6 of the Disaster Management Act, 2005 on 24 March 2020, followed by four phases of lockdown and then gradual unlock of the country. The rationale behind the same was to avoid social contact. Alcohol dispensing was also stopped during this time and was among the rst services to be reopened by the States. We propose in this paper that this lifting of ban on alcohol sale during the pandemic has led to a signicant increase in the number of COVID-19 cases in the country. METHODS: This is a prospective, observational study, done by collecting data from the Aargya Setu App, which is a mobile application launched by the Ministry of Health and Family Welfare on 2 April 2020 for contact tracing and elf assessment of COVID-19. The data of cumulative number of cases in 12 selected states of the country were compared before and after the lift of ban of alcohol and signicance was shown by the paired t test. RESULTS: The number of COVID-19 positive cases in the country during nationwide lockdown with simultaneous ban on alcohol sale when compared to cumulative number of cases after the lift of ban of alcohol sale during Lockdown and initial Unlock is statistically signicant (p = 0.04) CONCLUSION: We found that the decision to restart the sale of Alcohol could have been a factor for rise in number of cases in the country in the given timeframe. The decision to start the sale has also not been in accordance with the Indian Constitution and against the nation's founding ethics.

Technical regulation for the values of hydraulic parameters of used metal pipes in order to extend the period of their use

2021 ◽  
Vol 18 (3) ◽  
pp. 421-427
Author(s):  
Oleg A. PRODOUS ◽  
◽  
Lev D. TEREKHOV ◽  
Petr P. YAKUBCHIK ◽  
Alexander S. CHERNIKH ◽  
...  
Keyword(s):  
Practical Importance ◽  
Hydraulic Calculation ◽  
Technical Regulation ◽  
Supply Networks ◽  
Steel Pipes ◽  
Head Losses ◽  
Metal Pipes ◽  
Inner Diameter ◽  
Pumping Equipment ◽  
The Given

Objective: To compare the characteristics of hydraulic potential in worn steel pipes with internal deposits subjected to cleaning by mechanical and chemical methods. Methods: Calculated dependencies are used for hydraulic calculation of new metal pipes and pipes with internal deposits. Results: A calculated dependence was obtained to determine the value of the inner diameter of pipes with any thickness of the layer of internal deposits. The concept of an efficient pipeline is introduced and a comparison made of the values of head losses in new pipes and in pipes with internal deposits. A specific practical example is considered. For the given example, compare the values of energy consumption of pumping equipment for two methods of cleaning the inner surface of pipes. Measures are indicated to ensure the efficiency of operation of water supply networks. Practical importance: It is shown that the chemical method of technical regulation of the hydraulic characteristics of new steel pipes provides an extension of the period of their further use.

scholarly journals Awareness on Drudgery Reducing Farm Technologies for Gender Equity

2020 ◽  
pp. 9-19
Author(s):  
V. Vijaya Lakshmi ◽  
J. Deepika
Keyword(s):  
Capacity Building ◽  
Gender Equity ◽  
Training Programme ◽  
Farm Women ◽  
Crop Season ◽  
Before And After ◽  
Seed Placement ◽  
Training Programmes ◽  
Adoption Level ◽  
The Given

Agriculture in India is moving away from animal driven to machine driven. Apart from tractors and power weeders which are used by farmers, there are farm tools and implements that can be used by farm women to reduce their drudgery with increased productivity. The present study made an attempt in introducing the set of 14 drudgery reducing farm tools and implements i.e. sapling transplanter, sickle/kurpi, long handle weeders, three types of harvest bags, ring cutter, finger guards, milking stand cum stool, head load manager, seed cum fertilizer bag, seed placement tube and fertilizer broad caster. A capacity building training programme was conducted to the farm women for exposure about the improved set of farm tools and implements. The implements were given to village secretary for use of this equipment by a group of 50 farm women and data were collected from them regarding the awareness about the technologies before and after the capacity building training programmes. Adoption levels were assessed after completion of a crop season. It was found that partial awareness was there about the improved equipment before training and cent per cent awareness was in the random selected group after the training programs. About 62 per cent of the sample has moderately adopted the given technologies. The study indicated for educating the farmers about the importance of drudgery reducing technologies, training them in using the farm implements and providing them to have an easy accessibility to enhance the adoption level. Custom hiring centres can be the solution to house the improved technologies suitable for farm women so that they can be used on rotation basis.

scholarly journals УТИЦАЈ КУРСЕВА ИЗ ЛОГИКЕ НА СТАВОВЕ СТУДЕНАТА

2021 ◽  
Vol 3 (1) ◽  
pp. 15-27
Author(s):  
Милан Јовановић
Keyword(s):  
Empirical Inquiry ◽  
Before And After ◽  
Students Attitudes ◽  
The Given ◽  
Do So

In this paper we survey and analyse the results from the project dedicated to the question – do logic courses influence students attitude concerning logic, and if they do, in which way? Our main prediction was that the logic courses do significantly influence relevant students’ beliefs, and that influence (or the change) varies depending on the theoretical direction of the course in question. The method of our empirical inquiry was test-based examination of students’ attitudes towards specific claims. We conduct the testing twice, before and after students have went through the relevant courses, and then compared the tests. Results, although different from hypothesis to hypothesis, do generally support the conclusion that logic courses influence relevant students’ beliefs, and they typically do so in accordance to the theoretical direction of the given courses syllabuses.

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