Theoretical Research of the Axial Force about Cross Wedge Rolling

2010 ◽  
Vol 443 ◽  
pp. 27-32 ◽  
Author(s):  
Wen Fei Peng ◽  
Kang Sheng Zhang
Keyword(s):  
Axial Force ◽  
Frictional Force ◽  
Energy Parameter ◽  
Theoretical Research ◽  
Cross Wedge Rolling ◽  
Projected Area ◽  
Forming Quality ◽  
Area Reduction ◽  
Contact Surfaces

Axial force in CWR is an important force and energy parameter for stable rolling, which plays an important role in studying the forming quality of asymmetric shaft-parts, section shrinkage of rolled parts and rolling of heavy area reduction. By simplifying boundary conditions of solving axial projected area in this paper, and considering the effects of frictional force generated by contact surfaces between the tools and shaped shaft-section, the formula of the axial force has been derived by analytical method; by comparison of axial force values simulated by ANSYS/LS-DYNA FE software and measured through experiment, the formula of the axial force is verified correctly. The analyzing results provide useful reference for solving process problems caused by axial force.

Effect of rolling parameters on forming quality of flat cross wedge rolling thread shafts

2020 ◽  
pp. 095440892095259 ◽  
Author(s):  
YiYu Shao ◽  
WenFei Peng ◽  
Xuan Yu ◽  
Moliar Oleksandr ◽  
Vyacheslav Titov
Keyword(s):  
Axial Force ◽  
Element Model ◽  
Helix Angle ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Forming Quality ◽  
Rolling Parameter ◽  
The Right ◽  
Forming Angle

The flat cross wedge rolling is an advanced forming process, which is used to produce thread shafts. In this work, a finite element model of flat cross wedge rolling thread shafts was established by the DEFORM-3D, and the effect of the forming angle, spreading angle, helix angle and flank angle on forming quality are investigated. The research results show that the forming angle, spreading angle, helix angle have a significant influence on the position of the die wedge-in point. The angle designed wrongly makes the die wedge-in point unable to be aligned correctly, causing defects such as slipping in the process, repeated rolling of formed thread, thin or incomplete tooth shapes. The flank angle mainly makes an impact on the axial force. Reducing the right flank angle or increasing the left flank angle can effectively improve the imbalance of axial force to obtain high-quality thread shafts. Through the experiment of flat cross wedge rolling thread shafts, the data comparison demonstrates that the error of the external dimension of formed parts is small, proving the reliability of the rolling parameter selection.

Study in shaft end forming quality of closed-open cross wedge rolling shaft using a wedge block

2017 ◽  
Vol 93 (1-4) ◽  
pp. 1095-1105 ◽  
Author(s):  
Jie Wei ◽  
Xuedao Shu ◽  
Duanyang Tian ◽  
Wei Xiang ◽  
Yilun Wei ◽  
...  
Keyword(s):  
Cross Wedge Rolling ◽  
Forming Quality

Improving of quality of gate assembly contact surfaces of high-pressure fi ttings by diamond burnishing

2020 ◽  
pp. 99-104
Author(s):  
S.A. Zaydes ◽  
A.N. Mashukov ◽  
T.Ya. Druzhinina
Keyword(s):  
Surface Roughness ◽  
High Pressure ◽  
Main Part ◽  
Conical Surface ◽  
The Real ◽  
Metal Seal ◽  
Diamond Burnishing ◽  
Air Tightness ◽  
Contact Surfaces

The contact belt of the gate assembly is the main part of high pressure fittings. The serviceability of the fittings assembly as whole depends on the air-tightness and quality of the mating surfaces. The technology of diamond burnishing allows to increase the interface of the nodes by red ucing the surface roughness of the metal-to-metal seal. The real experience for improving of the fittings contact belt due to the use of diamond burnishing of the nozzles seats and the conical surface of the rods.

Death or Declaw: Dealing with Moral Ambiguity in a Veterinary Hospital

2005 ◽  
Vol 13 (4) ◽  
pp. 315-342 ◽  
Author(s):  
Dana Atwood-Harvey
Keyword(s):  
Medical Practice ◽  
Organizational Support ◽  
Theoretical Research ◽  
Best Interest ◽  
Political Debate ◽  
Self Identity ◽  
Staff Members ◽  
Moral Ambiguity ◽  
Veterinary Hospital

AbstractThe medical practice of declawing has received much political debate over the past few years. Yet, empirical and theoretical research on how this practice is maintained and the ethical positions of those who actually participate in this work is lacking. Drawing from 9 months of ethnographic fieldwork in a feline-specific veterinary hospital and open-ended interviews with veterinarians and staff, this study examines veterinary staff members' attitudes toward, and strategies for, dealing with the medical practice of declawing. Specifically, findings show that a number of staff felt uncomfortable with their participation in onychectomy (declawing) and relied heavily on organizational support structures to cope both with these feelings and the moral ambiguity about the practice. Relying on these structures, the veterinarians and their staff are able simultaneously to define felines as subjects worthy of respect for their quality of life, protect their own self-identity as people who work toward the best interest of animals, and paradoxically support action toward felines that they find morally objectionable.

Influence Parameters Analysis of Forming Quality and System Dynamics Simulation of Vertical Steel Bar Benting

2013 ◽  
Vol 483 ◽  
pp. 280-284
Author(s):  
Xi Jian Zheng ◽  
Xin Zhuo Wang ◽  
Jin Meng Zhang ◽  
Yu Fei Zhu
Keyword(s):  
Simulation Analysis ◽  
Reference Value ◽  
Dynamics Simulation ◽  
Forming Quality ◽  
Steel Bar ◽  
New Process ◽  
Cutting Length ◽  
Bending Radius ◽  
The Relationship

The vertical steel bar bending forming is a kind of new process of bending method. The bending speed, bending radius and clamping length H which is the parameters of vertical steel bar bending machine , is directly affect the quality of bending forming parts. This paper calculated the length of reinforcement before being incised and the springback angle of bending steel bar which obtained the reasonable cutting length and bending Angle; Then based on rigid-flexible virtual prototype technology to build the dynamics model of vertical steel bar bending system. Through simulation analysis ,it obtained the relationship between bending speed, bending radius , clamping length H and forming quality of bending steel bar. In this paper, the analysis method have reference value to the design of similar steel bar bending machines.

Study on the effective discharge energy mechanism of vertical ultrasonic vibration assisted EDM processing

2021 ◽  
pp. 095440542110285
Author(s):  
Yinghuai Dong ◽  
Guangyan Li ◽  
Yan Wang ◽  
Jianbao Song ◽  
Shuo Yang ◽  
...  
Keyword(s):  
Ultrasonic Vibration ◽  
Theoretical Research ◽  
Discharge Energy ◽  
Movement Path ◽  
Energy Mechanism ◽  
Effective Discharge ◽  
Parameter Matching ◽  
Discharge Gap ◽  
Conventional Machining

Compared to traditional EDM processing, UEDM (Ultrasonic Vibration Assisted EDM) have a great improvement in optimizing discharge environment. In this study, ultrasonic vibration is attached to the electrode. According to the relative positional relationship between the movement path of the electrode tip and the discharge gap, four working states of UEDM are defined. The four working states are the path within the discharge gap, the path in contact with the edge of the discharge gap, part of the electrode end path outside the discharge gap, and the path in contact with the workpiece, respectively. States are analyzed from the effective discharge energy and discharge frequency. A mathematical model for effective discharge energy and surface roughness is established for two conventional working states. The correctness of the theoretical research is verified by experiments. As the experiment results shown, the influence of ultrasonic amplitude on the energy of UEDM is primary, while frequency is secondary. A working state with better discharge stability and higher discharge energy when the electrode end path is in contact with the edge of the discharge gap. In the first three conventional machining states, the surface quality of the workpiece increases with the increase of ultrasonic amplitude and frequency. The study can provide scientific guidance for parameter matching of UEDM.

Investigation on the influence of mandrel on the forming quality of thin-walled tube during free bending process

2021 ◽  
Vol 72 ◽  
pp. 215-226
Author(s):  
Cheng Cheng ◽  
Hao Chen ◽  
Jiaxin Guo ◽  
Xunzhong Guo ◽  
Yuanji Shi
Keyword(s):  
Forming Quality ◽  
Bending Process ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Free Bending

Electronic Resources for Online Mathematics Primary Education – Specifics, Types, Quality

2021 ◽  
Vol LXIV (1) ◽  
pp. 62-83
Author(s):  
Lyubka Aleksieva ◽  
Keyword(s):  
Mathematics Education ◽  
Online Education ◽  
Primary School ◽  
Primary Teachers ◽  
Theoretical Research ◽  
Future Research ◽  
Electronic Resources ◽  
Learning Content ◽  
Online Mathematics

This paper presents a theoretical research on electronic resources provided for mathematics education in primary school including online education, which has become ubiquitous as a result of the COVID-19 pandemic. Various aspects and forms of application of e-resources in mathematics education are explored in the literature, but the issue of their quality is less studied. E-resources potential to dynamically illustrate the mathematical learning content is defined as their main advantage, but this potential could be realized only in compliance with the principles of multimedia, as well as the requirements for accessibility, ergonomics and visual design. Therefore, in this study the parameters for the quality of e-resources for mathematics education in primary school are derived and specific criteria and requirements for their quality are proposed. Thus, in addition to providing a basis for future research, this paper could serve to primary teachers as a guide for measuring the quality of e-resources that they select or create for online mathematics education.

scholarly journals PENERBITAN JURNAL ILMIAH UNTUK MENINGKATKAN KUALITAS SUMBER DAYA MANUSIA

2010 ◽  
Vol 5 (2) ◽  
pp. 216-220
Author(s):  
B. P. Sitepu
Keyword(s):  
Human Resource ◽  
Scientific Journal ◽  
Experimental Results ◽  
Theoretical Research ◽  
Journal Articles ◽  
Academic Communities ◽  
Science Technology ◽  
Research Findings

Scientific journal is one of the periodical publications intended to widely disseminate research findings useful for research and academic communities. Articles published in the journal tend to be highly technical, representing the latest theoretical research and experimental results in the field of science, technolgy, or arts covered by the journal. Articles in the journal can be used as references and inspire researchers and scholars to do further researh. The quantity and quality of journals in a country can indicate the quality of the human resource and development of science, technology, and arts in the country. Based on the available data, the quantity and the quality of journal in Indonesia are still unsatisfactory. This article discusses some problems in managing journal and provides a number of recommendation which are useful for those publishing a journal.

scholarly journals Merytoryczne, psychopedagogiczne i dydaktyczne aspekty kształcenia nauczycieli języków obcych. Rozważania teoretyczne z aneksem empirycznym

2019 ◽  
pp. 243-255
Author(s):  
Zdzisław Aleksander
Keyword(s):  
Foreign Language ◽  
Working Conditions ◽  
Theoretical Research ◽  
Mutual Relationship ◽  
Language Teacher ◽  
Practical Education ◽  
Relationship Of ◽  
The Relationship

When looking at the relationship between substantive education and the pedagogical background of a teacher (foreign language teacher included) there has been an eternal disagreement both in the academia, as well as among prospective employers. The most essential controversy pertains to the degree of expertise a teacher should possess in the field they teach versus how much psycho-pedagogical and educational knowledge they should have and the mutual relationship of the two. Another area of dispute and debate within the teachers’ education specialism seems to occur between two parties: proponents of theoretical research and the narrow circle of practical education advocates. The empirical annex, which points to the level of vocational preparation of a language teacher, focuses on the choice of didactic activities, the quality of their execution, and the working conditions which are under a teacher’s control.

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