scholarly journals OVERVIEW OF MOBILE MACHINE DESIGNS FOR LARGE-SIZED PRODUCTS

2021 ◽  
Vol 6 (9) ◽  
pp. 97-112
Author(s):  
K. Marusich ◽  
V. Druzhinin
Keyword(s):  
High Accuracy ◽  
Mechanical Processing ◽  
Repair Facility ◽  
Time Required ◽  
Mobile Machine

The repair of large-sized products without a specialized repair facility is usually not available due to the impossibility of ensuring high accuracy when performing mechanical processing. Nevertheless, dismantling and moving large-sized items to the repair facility significantly increase the downtime of the equipment being repaired, or it is technically impossible to perform. Specialized machines that are used to repair large-sized items in such facilities are unique and expensive. They are heavily loaded and this can lead to various risks associated with the timing of the repair. Therefore, it is necessary to reduce the time required for dismantling, moving and processing large-sized items. In this regard, the rejection of these operations in favor of the use of mobile machines will significantly reduce the time and cost of repairs of large equipment. The article discusses domestic and foreign achievements in the field of mobile machines and systems that are used for maintenance and machining of large-sized products on site without dismantling. A number of designs of specialized mobile machines for use in various industries are described.

Influence of Dimensional Deviations on the Positioning Accuracy of Robots with Delta 3 DOF Parallel Structure

2014 ◽  
Vol 657 ◽  
pp. 839-843
Author(s):  
Dragos Andrioaia ◽  
Gheorghe Stan ◽  
Ion Cristea
Keyword(s):  
Design Process ◽  
High Accuracy ◽  
Parallel Structure ◽  
Mechanical Processing ◽  
High Quality ◽  
Accuracy Class ◽  
Positioning Accuracy ◽  
Mechanical Structure ◽  
Mechanical Elements

In the last years, due to the advantages presented by Delta 3 DOF parallel structure robots, they have been used in the field of high accuracy mechanical processing. In this field, it is demanded that the manufacture of components present high quality. The positioning accuracy for the parallel structure Delta 3 DOF robots can be affected by errors entered from the mechanical structure or by the control and command system. The accuracy class in which the mechanical elements are manufactured can affect the positioning accuracy within the robots with Delta 3 DOF parallel structure. In this paper, the authors study the ways in which the dimensional deviations of the kinematic elements influence the positioning accuracy. The method which is used correlates the dimensional deviations with the positioning accuracy. Therefore, the positioning accuracy of the Delta 3 DOF robots can be established within the design process.

scholarly journals Efektivitas Sistem Pelayanan Pembuatan Surat Izin Mengemudi (SIM) Secara Online di Satuan Penyelenggara Administrasi (Satpas) Colombo Surabaya

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Siti Fatimah
Keyword(s):  
Service Providers ◽  
Service System ◽  
High Accuracy ◽  
The Internet ◽  
Analytical Technique ◽  
Operational Management ◽  
Driver's License ◽  
Time Required ◽  
System Effectiveness ◽  
And Training

Effectiveness of Service System Making Driver's License (SIM) Online in Administrative Administrator Unit (Satpas) Colombo Surabaya Online SIM is applied for the creation of new SIM and SIM renewal. The purpose of this research is to know and describe the effectiveness of service system of SIM making online to know and describe the constraints faced in service system of SIM making online and to know and describe effort done to improve system effectiveness of service of SIM making online. Analytical technique used is descriptive qualitative. The results showed that the effectiveness of the service of making Driver's License (SIM) online is known from several factors, namely: a) Time factor; shows that the time required in service is 15 to 20 minutes; b) Accuracy factors; indicates that the staff or the party providing online services has a high accuracy and accuracy so that in practice rarely found an error in the process of service being run; and c) Service-style factors; it is known that the style of service providers in this case is the staff or parties as performing the duties and responsibilities of work in accordance with applicable SOP and existing. The results also show that online SIM services are considered to be effective but not maximal considering there are still some obstacles in the implementation. These constraints consist of: a) there are still people who do not know clearly about the mechanism of the SIM online; b) the number of staff is considered to be lacking; c) there is a connection or network trouble; d) The Administrative Administrator Unit Colombo Surabaya still uses the conventional system in the implementation of its operational management; and e) still under renovation. In relation to the apparent constraints, efforts are made to improve the effectiveness of SIM-making services online by conducting socialization through television and radio and socializing the ball pickup system; making additional staff as needed, the Parties may cooperate with the service provider; and updating IT-based infrastructure and training in the use of information technology-based infrastructure or the Internet. Keywords: Effectiveness, Service, Driver License (SIM) online

scholarly journals Kinematic-PPP using Single/Dual Frequency Observations from (GPS, GLONASS and GPS/GLONASS) Constellations for Hydrography

2018 ◽  
Vol 53 (1) ◽  
pp. 37-46
Author(s):  
Ashraf Farah
Keyword(s):  
High Accuracy ◽  
Observation Time ◽  
Single Frequency ◽  
Dual Frequency ◽  
Differential Gps ◽  
International Gnss Service ◽  
Comparable Accuracy ◽  
Kinematic Ppp ◽  
Time Required ◽  
Different Sources

Abstract Global Positioning System (GPS) technology is ideally suited for inshore and offshore positioning because of its high accuracy and the short observation time required for a position fix. Precise point positioning (PPP) is a technique used for position computation with a high accuracy using a single GNSS receiver. It relies on highly accurate satellite position and clock data that can be acquired from different sources such as the International GNSS Service (IGS). PPP precision varies based on positioning technique (static or kinematic), observations type (single or dual frequency) and the duration of observations among other factors. PPP offers comparable accuracy to differential GPS with safe in cost and time. For many years, PPP users depended on GPS (American system) which considered the solely reliable system. GLONASS's contribution in PPP techniques was limited due to fail in maintaining full constellation. Yet, GLONASS limited observations could be integrated into GPS-based PPP to improve availability and precision. As GLONASS reached its full constellation early 2013, there is a wide interest in PPP systems based on GLONASS only and independent of GPS. This paper investigates the performance of kinematic PPP solution for the hydrographic applications in the Nile river (Aswan, Egypt) based on GPS, GLONASS and GPS/GLONASS constellations. The study investigates also the effect of using two different observation types; single-frequency and dual frequency observations from the tested constellations.

Modeling of Grained Heterogeneity with Voronoi Tessellation in Microforming Process

2014 ◽  
Vol 553 ◽  
pp. 66-70 ◽  
Author(s):  
Zhi Fang ◽  
Zheng Yi Jiang ◽  
Dong Bin Wei
Keyword(s):  
Process Modeling ◽  
Voronoi Tessellation ◽  
High Accuracy ◽  
Mechanical Processing ◽  
Fe Modelling ◽  
Single Grain ◽  
High Utilization ◽  
Simulation Results ◽  
The Relationship ◽  
Good Agreement

Microforming technology has attracted more and more attention because of its high utilization in almost every field. However, due to size effect, the conventional scale mechanical processing theories could not be applicable. Further, the characteristic of each single grain involved in the deformed area activates to play a significant role in the manufacturing process. In order to reflect and investigate the relationship among these grains better, this paper represents a pre-process modeling method with Voronoi tessellation to reveal the grained heterogeneity of workpiece numerically in order to obtain high accuracy and prediction result in finite element (FE) modelling of microforming process. Corresponding micro V-bending experiments have been carried out, and the experimental results are in good agreement with simulation results in terms of final angles after micro bending with consideration of springback.

scholarly journals Strengthening of materials by vibroimpact and combined methods with previous electrochemical processing

2018 ◽  
Vol 224 ◽  
pp. 01097 ◽  
Author(s):  
Alexander I. Boldyrev ◽  
Alexander A. Boldyrev ◽  
Oleg N. Fedonin
Keyword(s):  
Anodic Dissolution ◽  
Cold Work ◽  
High Accuracy ◽  
Experimental Investigations ◽  
Mechanical Processing ◽  
Technological Capabilities ◽  
Electrochemical Processing ◽  
Evaluation Test ◽  
Ultimate Resistance ◽  
Combined Methods

The authors examine capabilities of vibroimpact strengthening after electrochemical processing of materials, also getting guaranteed cold work of the surface during simultaneous anodic dissolution and mechanic calibration. They propose the technique of electrochemical mechanical processing. This article contains the results of experimental investigations. This technique passed evaluation test during production of shell cases with high accuracy and guaranteed hole cold work. The received results give ground for affirmation that electrochemical processing that proceeds hardening enables great extension of technological capabilities of this method and successful continuation investigations directed at creation of lighter constructions with higher ultimate resistance at reversed loads.

scholarly journals A quantitative study on using digital photoelasticity for characterising the effect of the stretching speed on the necking phenomenon

2020 ◽  
Vol 40 (9) ◽  
pp. 753-762
Author(s):  
Ahmed A. Hamza ◽  
Taha Z. N. Sokkar ◽  
Mohammed A. El-Bakary ◽  
Amira A. S. Azzam
Keyword(s):  
Quantitative Study ◽  
Formation Mechanism ◽  
Isotactic Polypropylene ◽  
Mechanical Processing ◽  
Processing Conditions ◽  
Digital Photoelasticity ◽  
Time Required ◽  
As If

AbstractThe digital photoelastic technique is used to characterise the necking behaviour of isotactic polypropylene (iPP) fibres. The effect of stretching rate on necking initiation is studied. The birth of necking is observed using photoelastic patterns of the stretched fibres to understand how the localised difference between the principle stresses grows to form a necking region. Finally, the formation of multiple necking regions is characterised photoelastically. These multiple necks are initiated using the same formation mechanism and conditions as if there is only a single necking region. It was evident that, fast stretching causes faster arrangement of molecular chains and hence decreases the time required for necking initiation. Recommendations are suggested for optimum mechanical processing conditions of iPP fibres to avoid failure by necking. Photoelastic patterns are given for illustration.

Influence of Thermo-Mechanical Processing on the Microstructure of Beryllia Dispersed Nickel Alloys

1973 ◽  
Vol 31 ◽  
pp. 184-185
Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant
Keyword(s):  
High Temperature ◽  
Nickel Alloys ◽  
Thermomechanical Processing ◽  
Cold Work ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Mechanical Processing ◽  
Uniform Dispersion ◽  
Oxide Particles ◽  
Nickel Base

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.

The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

1970 ◽  
Vol 28 ◽  
pp. 278-279
Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Surface Tension ◽  
Critical Point ◽  
Freeze Drying ◽  
Attractive Alternative ◽  
Crystal Formation ◽  
Critical Point Drying ◽  
Time Required ◽  
Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

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