In the paper a new procedure based on the simple arithmetic operations for location and quantification of damage in beams using incomplete static information is presented. The grey system theory is employed to locate damage in beam structure using static displacements for two structural stages. Once the location of damage is known, the damage quantification can be done by comparing the displacement curvatures of intact and damage stage of structure. The set of numerical simulations on simply supported beam is conducted to determine the damage quantification reliability of proposed procedure for different damage severities. Also, the results of laboratory test are employed to verify results obtained by numerical simulations.
Machines. Technologies. Materials.
Vol. 8 (2014), Issue 9
Table of Contents
The article describe the design and operation of a prototype of satellite pump and a prototype of satellite motor. In both machines, the operating mechanism consists of a non-circular gear with external teeth (rotor), non-circular gear with internal teeth (curvature), and ten gear wheels which cooperate with the rotor and the curvature. The differences between the commutation unit in the pump and the commutation unit in the motor are described. The principle of axial clearances compensation in the pump and in the motor is also presents. The article contains the values of the losses and the efficiency of these machines supplied with rapeseed oil, HFA-E emulsion and pure tap water. The results of durability tests of motor supplied with HFA-E emulsion and rapeseed oil are also presented.
SOCIAL RESPONSIVENESS OF RUSSIAN BIG INDUSTRIAL BUSINESS AGANIST THE BACKDROP OF A GLOBAL FINANCIAL CRISISpg(s) 12-14
Modern society is developing in conditions of pressing social, economical and ecological problems. Since Russian big industrial business as part of society has an effect on its development, social responsiveness becomes increasingly important. Value of social responsiveness is in minimizing negative implications of company production operation, in solving climate, global and local development.
Thanks to social responsiveness business becomes more well-established socioeconomically, gets an opportunity of increasing its intangible assets.
APPLYING ULTRASONIC PRESSING IN MANUFACTURING SLIP BEARINGS MADE OF COMPOSITE MATERIAL BASED ON POLYTETRAFLUOROETHYLENpg(s) 15-16
The influence of parameters of ultrasonic pressing on the mechanical and tribological properties of composite materials on the basis of polytetrafluoroethylene is considered. A new technology for the friction bearings production is proposed and its advantages are shown.
The article describes the design and operation of a prototype hydraulic unit. It is based on an inversed kinematics, satellite pump in which the body rotates around the shaft. The pump is placed inside the electric motor. Thanks to that the compact and low mass construction was achieved. Thanks to new commutation unit with enlarged channels, lower pressure losses were obtained. The article presents the construction and results of preliminary tests.
The CO laser welding technique was suggested as a method of joining dissimilar materials. The corrosion resistance at high 2 temperatures of the joint of TP347HFG and VM12-SHC stainless steel was investigated. The stainless steel was butt welded. Materials were examined by the thermogravimetric method. The surface and microstructure of the sample were observed in a scanning electron microscope (SEM). The results showed the substantial intermixing of both substrates within the fusion zone. The thermogravimetric data indicate that at high temperatures and air condition the joint and the stainless steel undergo chemical corrosion. The joint has acquired medium resistance for chemical corrosion in relation to both steels.
Ordinary in the theory of machine elements a deterministic stress conditions are used. In general case there are relationships between “acceptance stress” and “working stress”. In practice the stresses are random values. Therefore the stress conditions have got probabilistic formulation.
In this paper the probabilistic formulation of stress conditions for machine elements are presented.
The liquid bismuth network formation along grain boundaries (GB) and triple junctions (TJ) was investigated in copper polycrystalline samples. The experimental observation in situ technique of Bi penetration through the Cu plate was used. The temperature dependence of the penetration rate of the melt through the wafers of polycrystalline copper and the effective activation energy of penetration of Bi along the GBs are found.
The authors report on the essence of risk management in the enterprise as an effective management tool in today’s rapidly changing business environment. The report targeted to indicate the attitude of the managers in this process, based on a survey, as demonstrate the need for a more comprehensive approach to risk management.
In this paper, we present an object detection system and its application to plasma sprayed coatings implants with the classifier based on the Principal Component Analysis (PCA). In order to improve performance of the classifier, we used combinations of halftone images and gradient images generated by the Sobel operator. To improve the quality of plasma coatings we apply intelligent control methods based on artificial neural networks and Bayesian network for optimization the weights
COMMERCIALLY PURE COPPER AND LOW-ALLOYED CHROME BRONZE IN TRIBOLOGICAL CONTACT WITH GRAPHITIFEROUS MATERIALpg(s) 36-39
This work presented the results of tribological studies of commercially pure copper (Cu 99.9%) and low-alloyed chrome bronze Cu-1%Cr in contact with a graphitiferous plate EK-40. Samples from copper and copper alloy were prepared to obtain two kinds of grain size of microstructure. Two schemes were used for tribological studies. The first scheme was used during reciprocal movement to evaluate the friction coefficient. The second scheme was employed to evaluate the shear strength of adhesive bonds and the adhesive component of the friction coefficient.Besides, the fulfilled studies determined that the tribological properties of materials depended on the grain size of microstructure. It is shown that an ECAP–Conformed specimen with UFG exhibits 20-30% lower friction coefficients than that of annealed specimen with CG structure. The tribological test results showed that the coefficient of friction decreased, with the decreasing grain size. Therefore, were conclude the coefficient of friction of proposed materials is microstructure-sensitive.
Today the development of formalized methods of synthesis of chain transmission for mechanical engineering are observed.
Solving it gives the opportunity to raise designing quality and labor productivity of the designer and the constructor when applying these methods directly in computer-aided design.
Comparative analysis of dynamics 3D computer design modeling of chain transmission in metal and polymer design by means of program complex SolidWorks are presented. From the analysis of graphic dependences precisely traced advantages of application components of polymer composites as compared with traditional metal parts of chain transmission: dynamic loads in chain contour, force of the impact between the oncoming roller and sprocket, dynamic irregularity of rotation the sprockets.
Nowadays the field of Rapid Prototyping is rapidly changing and providing a clear overview is challenging. One of the biggest problems in this context is that different operations are often named similar. In the beginning of this paper the most important related terms are defined and classified. Afterwards the major Rapid Prototyping techniques, called generative manufacturing methods, are explained.
Alternatives to these generative methods as well as 3D-scanning methods are dealt with too. All in all these emerging technologies around 3D-printing and 3D-scanning are revolutionizing the way Rapid Prototyping laboratories look like. They offer new possibilities and reduce the complexity of prototyping. One of the future trends is so called Fab Labs which are currently stretching the boundaries of the common Rapid Prototyping laboratories. At Graz University of Technology the second Fab Lab in Austria has been established lately. Especially its implementation in University education as part of the Product Innovation Project is discussed in detail.
VIBRATION MONITORING FOR FAULT DETECTION AND PROCESS CONTROL OF THE MOTOR-MIXER AGREGATE IN FENI INDUSTRY-MACEDONIApg(s) 47-51
One of the larger aggregates for production nickel in Feni – INDUSTRIES- Macedonia, is assembly machine mixer 1 and mixer 2. The proper functioning of aggregate depends on the prevention and early detection of damaged parts. Given that the aggregate works non-stop for 24 hours, its failure means termination of operation of furnaces for nickel, and thus the entire production. It means a loss of time, deviation from the production plan, loss of markets and loss of a lot of money. It is a very important to constantly monitor the vital parts rightness. Therefore regularly perform frequency analysis of engine bearings and mixer bearings. Aggregate is composed of: motor, hydro coupling, reducer, mechanics coupling, and mixer.
This paper provides the results of frequency analysis of measured vibration of these parts, compared with limited values and recommendations for quick actions in removing the damaged parts in time periods with the least losses. That means pre timely delivery of bearings, preparation of aggregates for quick repairs with a short downtime. You will also be given a techno – economic analysis to save funds by using this method.
The results of computer simulation and physical experiment on angular pressing AD1 alloy billets are presented. There were microstructure and dyurametrix researches to confirm the changes in the structure of the structure and its mechanical properties.