An Accurate Digital Grinding Method on Inner Surface of Thin-Walled Rotary Part

2007 ◽  
Vol 329 ◽  
pp. 137-144
Author(s):  
Z.W. Ren ◽  
Yong Qi Wang ◽  
Zhen Yuan Jia ◽  
X.J. Sheng
Keyword(s):  
High Speed ◽  
Complex Surface ◽  
Technical Requirements ◽  
Grinding Method ◽  
Inner Surface ◽  
Rotary Parts ◽  
Cubic Polynomial ◽  
Thin Walled ◽  
Physics Performance ◽  
In Suit

The physics performance of thin-walled rotary parts made of hard brittle material on high-speed aerocraft cannot meet the technical requirements after semi-finished processing, in order to compensate the physics performance, the wall thickness should be properly grinded based on the inner surface reference in the finish machining. A processing method consisted of measuring, calculating and grinding functions is investigated. The data of complex surface is obtained with trigger measuring technology, and the reconstructed profile is calculated with cubic polynomial approaching algorithm, which has fast and stable merits in suit with efficient machining. The grinding G program is generated according to the concrete construction of machining tool. This method has been verified by experiments.

Experimental study on cutting factors of multi-layer machining for large aerospace thin-walled structural parts

2021 ◽  
pp. 095440892110403
Author(s):  
Hangzhuo Yu ◽  
Han Zhong ◽  
Yong Chen ◽  
Lei Lin ◽  
Jing Shi ◽  
...  
Keyword(s):  
Coordinate System ◽  
Experimental Method ◽  
Cutting Parameters ◽  
Machining Process ◽  
Machining Error ◽  
Machining Errors ◽  
Inner Surface ◽  
Thin Walled ◽  
Optimal Cutting Parameters ◽  
Cutting Path

Large aerospace thin-walled structures will produce deformation and vibration in the machining process, which will cause machining error. In this paper, a cutting experimental method based on multi-layer machining is proposed to analyze the influence of cutting tool, cutting path, and cutting parameters on machining error in order to obtain the optimal cutting variables. Firstly, aiming at the situation that the inner surface of the workpiece deviates from the design basis, the laser scanning method is used to obtain the actual shape of the inner surface, and the method of feature alignment is designed to realize the unification of the measurement coordinate system and machining coordinate system. Secondly, a series of cutting experiments are used to obtain the machining errors of wall thickness under different cutting tools, cutting paths, and cutting parameters, and the variation of machining errors is analyzed. Thirdly, a machining error prediction model is established to realize the prediction of machining error, and the multi-objective optimization method is used to optimize the cutting parameters. Finally, a machining test was carried out to validate the proposed cutting experimental method and the optimal cutting parameters.

Technology of the Contact Wire Manufacture for High-Speed Railways

2021 ◽  
Vol 410 ◽  
pp. 173-178
Author(s):  
Andrey V. Sulitsin ◽  
Raisa K. Mysik ◽  
Vadim V. Morgunov
Keyword(s):  
High Speed ◽  
Profile Analysis ◽  
Cold Drawing ◽  
Casting Process ◽  
Sediment Layer ◽  
Contact Wire ◽  
X Ray ◽  
Inner Surface ◽  
Full Profile ◽  
Continuously Cast

The article presents an overview of possible technological schemes to produce an overhead contact wire for railways. Pilot experiments were carried out on the manufacture of a contact wire made of CuMg0.3, CuMg0.4 and CuMg0.5 alloys and having a nominal cross section of 100 mm2. The contact wire was obtained from a continuously cast rod with small section, which was subjected to plastic deformation using the Conform technology and cold drawing of the extruded rod. In the casting process, we encountered the formation of cracks on the cast rod surface and the rods breakage. The inner surface of the graphite bushings of the mold after casting the rod was studied and a thin gray layer was found on the inner surface of the graphite bushings. Areas of the graphite bushing with gray layer were studied by scanning electron microscopy and element-by-element mapping was performed with the selection of a spectrum in the sediment layer area. In order to determine the phase composition of the sediment layer it was analyzed by the method of full-profile analysis of the X-ray diffraction pattern according to Rietveld. X-ray phase analysis showed the CuMg2 and Cu2Mg phases presence. This allowed us to assume a possible mechanism for the formation of the sediment layer. Ultimate tensile strength, elongation and electrical resistivity was determined. Analysis showed that the overhead wires made of CuMg0.3, CuMg0.4, CuMg0.5 alloys meets the requirements of GOST R 55647-2018 for wires made of the second conditional group bronze.

scholarly journals HIGH-SPEED ROLLING STOCK OF UKRAINE

2021 ◽  
pp. 32-42
Author(s):  
О.М. Safronov ◽  
Keyword(s):  
High Speed ◽  
Brake System ◽  
Rolling Stock ◽  
Joint Stock Company ◽  
The European Union ◽  
Stock Company ◽  
Passenger Traffic ◽  
Technical Requirements ◽  
The World ◽  
Electric Train

A brief history of the development of high-speed passenger traffic in the countries of the world is shown, it is shown that the length of high-speed highways (SMM) in the world is 44 thousand km. Despite the fact that Ukraine is not included in the list of 28 countries with the SMM, a two-system electric train ECR1 "Tarpan" was created on the basis of the PUBLIC JOINT STOCK COMPANY "KRYUKOVSKY RAILWAY CAR BUILDING WORKS" (PJSC "KVBZ") for the speed of movement of more than 200 km / h. A description of the electric train and the peculiarities of the brake system are given. It is shown that the brake system corresponds to world counterparts for high-speed trains about what evidence test results, which, due to the lack of ATS, were carried out for a speed of 160 km / h. The results of the settlement research, using the mathematical model and the results of the driving brake tests, showed that the braking pathway of the electric train at a speed of 200 km / h is 1539 m, and at a speed of 300 km / h - 3172 m. The obtained brake path values comply with the technical requirements of the European Union TSI . Studies confirm that Ukraine has high-speed rolling stock for speeds up to 300 km / h. Key words: high-speed rolling stock, electric train, brake system, brake path, speed

scholarly journals Influence of microadditive of carbon dioxide on the kinetics of boiling-up of superheated w-pentane

2021 ◽  
Vol 2039 (1) ◽  
pp. 012027
Author(s):  
S A Perminov ◽  
E V Lipnyagov ◽  
M A Parshakova
Keyword(s):  
High Speed ◽  
Gas Adsorption ◽  
Glass Tube ◽  
Initial Value ◽  
Active Centers ◽  
High Speed Video ◽  
Inner Surface ◽  
Vertical Glass ◽  
Attainable Superheat ◽  
Kinetics Of

Abstract The effect of a low-boiling impurity (CO2 gas <1.5% mol) on the kinetics of boiling-up of superheated n-pentane in a vertical glass tube have been studied by high-speed video (2050 fps). The method of continuous pressure decrease from 2.00 to 0.10 MPa (in the temperature range of 100.2-145.1 °C), as well as the method of measuring the lifetimes of superheated liquids at 0.10 MPa (90.2-134.1 °C) have been used. The inner surface of the tube has two visible defects, one of which defines the boundary of the attainable superheat. After degassing the system, the defects of tube cease to play an appreciable role, the active centers are redistributed. The temperature of the attainable superheat increases from the initial value by 20 °C in tests with gas and by 10 °C in subsequent tests without it. The result obtained may be related to physical gas adsorption on the glass surface during the process of evacuation of the system.

Energy and Eco-Sustainability using Pressure-less Silver Sintering for RF Power Electronics

2019 ◽  
Vol 2019 (1) ◽  
pp. 000344-000359
Author(s):  
Evan A. Hueners ◽  
Richard D. Hueners ◽  
Anthony D. F. O' Sullivan ◽  
M. Redzuan Zin
Keyword(s):  
Power Electronics ◽  
High Speed ◽  
Bond Line ◽  
Acoustic Microscopy ◽  
Rf Power ◽  
Technical Requirements ◽  
Die Attach ◽  
Effective Manner ◽  
Confocal Scanning ◽  
Silver Sintering

Abstract Energy & Eco-Sustainability using Pressureless Silver Sintering for RF Power Electronics A virtually void free die attach was successfully achieved using a fixed but critical volume of Ag sinter paste by a process of pressureless sintering on a multi-axis cartesian style bonder, retro-fitted with with a high-speed jetting dispenser. While this process potentially offered an ideal combination of cost-effectiveness, control and speed, it required the development of additional software protocols to secure the level of performance demanded of the dispenser to meet exacting technical requirements. This proprietary adaptation we term “Fixed BLT” software, and over five test pieces we were consistently able to deliver a fixed height bond-line of circa 70% of bond height, translating as 50 um before sinter and 30 um after. In each case the result was a virtually bond free void secured in a timely, repeatable, commercially effective manner. The absence of voids was verified through industry standard non-destructive analysis utilizing confocal scanning acoustic microscopy (CSAM).

scholarly journals Study on the Composite Structure of Aluminum Foam-Filled Thin-Walled Metal Tube to Reduce the Charge Overload inside the Projectile during the Penetration Process

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Fudi Liang ◽  
Zengyou Liang ◽  
Dezhi Deng
Keyword(s):  
Reinforced Concrete ◽  
Stress Analysis ◽  
Composite Structure ◽  
High Speed ◽  
Aluminum Foam ◽  
Metal Tube ◽  
Penetration Process ◽  
Mathematical Expressions ◽  
Foam Filled ◽  
Thin Walled

When a projectile penetrates a target at high speed, the charge loaded inside the projectile usually bears a high overload, which will consequently severely affect its performance. In order to reduce the overload of the charge during the penetration process, the structure of the projectile was improved by adding two buffers at both ends of the charge. In this study, the mathematical expressions were first gained about the axial buffering force generated by the thin-walled metal tube, aluminum foam, and the composite structure of aluminum foam-filled thin-walled metal tube when they were impacted by the high-speed mass block through reasonable assumptions and stress analysis. During the experiment on the high-speed projectile penetrating reinforced concrete target, the acceleration curve of the charge and the projectile body were obtained. The results show that the maximum overload that the charge was subjected to during the launch and penetration process was significantly reduced, and the change in overload, which the charge was subjected to during the penetration process, was also less obvious.

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