Calculation of quality parameters of the functional surfaces of steady-rests |
Author : Erokhin V.V. |
Abstract | Full Text |
Abstract :The article considers the methodology for calculating the design parameters of the functional surfaces of the steady-rests, which determine the accuracy and productivity of surface treatment of blanks. A mathematical model for calculat-ing the quality parameters of the functional surfaces of fixed steady-rests is presented. This model is built on the basis of the guaranteed result method and assumes: the inner and outer cylindrical surfaces of self-centering lunette rollers are elliptical and misaligned axes; Contact of the rollers with the workpiece is elastic; The rollers are pre-pressed to the elliptical surface of the workpiece with forces ensuring constant contact between the rollers and the workpiece; The rollers rotate at a constant angular velocity. |
|
The likelihood of failures in the operation of the lifting mechanism electrical hook bridge crane |
Author : Ritenman I.L., Ritenman V.I., Bleyshmidt L.I. |
Abstract | Full Text |
Abstract :Given the application of the methods of analysis of types and consequences of failures (FMEA analysis) to assess the technical risk of occurrence of emergency situations during the operation of the lifting mechanism electrical hook bridge crane. The technique allows to identify the limiting elements and to determine the significance of effects in the design of the lifting mechanism, to develop measures to reduce the risk of the occurrence of an emergency. |
|
Aspects of the design of the automated system for code generation of electrical items of technological equipment |
Author : Erokhin V.V., Eliseeva E.V. |
Abstract | Full Text |
Abstract :The article presents the aspects of designing an automated system for generating codes for electrical elements of process equipment using CASE-means. We propose our own technology of iterative development of such systems. The pro-posed methodology uses the tool to develop the ERwin Data Modeler databases of Computer Associates and the au-thor’s tool for the automatic generation of ERwin Class Builder code. The implemented design tool is a superstructure over the ERwin Data Modeler from Computer Associates, which extends its functionality. ERwin Data Modeler works with logical and physical data models and allows you to generate a description of the database and ddl-scripts. |
|
Equalization of bearing loads on running wheels of overhead crane load trolley when applying multi-purpose layout drawing |
Author : Goncharov K.A., Denisov I.A. |
Abstract | Full Text |
Abstract :The paper deals with the approach to design ofthe equalization procedure of bearing loads on running wheels of a load trolley. Methodological ambiguity in the trolley design issue resulting in complication of the designing process was identified. There was formed and solved the task concerning compensation of variation in the position of the common resultant of forces acting on the trolley from the point characterizing optimal load distribution between the wheels. This distribution was achieved by introducing a conventional mass and using appropriate dependencies and imposed limitations. Different options for arrangement of actual masses which form the conventional mass under the multi-purpose metal construction scheme were considered. An example on how to address the presented issue for the overhead crane load trolley was considered. The paper presents the findings of usefulness of various schemes of mass arrangement depending on a design situation. The need to apply the hinged frame method for determining bearing loads on the running wheels of the trolley based on the multi-purpose layout drawing was identified. |
|
Research of efficiency of the algorithms for finding solutions based on the use of functional semantic networks |
Author : Mironova M.N. |
Abstract | Full Text |
Abstract :The questions of ?alculation of parameters of drives are considered in this article. An approach based on the technologies of functional semantic networks was used. The problem of calculating and designing drives based on the use of a functional semantic network is considered. Deterministic and random algorithms for searching for optimal solutions are analyzed: coordinate-wise method, multipath, random search with a return. A combined algorithm for finding a solution on a functional semantic network, combining a random search with a return and a method of coordinate-wise descent, is developed. |
|
Genetic algorithm for minimizing the energy costs for the reorientation of the plane of the spacecraft orbit |
Author : Pankratov I.A. |
Abstract | Full Text |
Abstract :In the quaternion formulation, the problem of optimal reorientation of the orbital plane of a spacecraft (SC) is considered. The control (acceleration from the vector of the jet thrust orthogonal to the plane of the orbit) is limited in magnitude. It is necessary to minimize energy costs for the reorientation of the plane of the spacecraft orbit. An actual special case of a problem when the spacecraft orbit is circular, and control assumes constant values in certain sections of the active motion of the spacecraft is considered. An original genetic algorithm for finding the trajectories of optimal spacecraft flights is constructed. No information about the unknown initial values of the conjugate variables is required when we apply this method. Examples of the numerical solution of the problem are given for the case when the difference between the initial and final orientations of the spacecraft orbit equals to a few degrees in angular measure. In this case, the final orientation of the plane of the spacecraft orbit corresponds to the orientation of the orbital plane of the satellites of the Russian GLONASS orbital grouping. |
|
Experimental study of influence of installation faults on tractive ability of belt conveyor intermediate drive |
Author : Goncharov K.A., Grishin A.V. |
Abstract | Full Text |
Abstract :The paper deals with the results of the experimental study of influence of installation faults on tractive ability of belt conveyor intermediate drive. The alternative of experimental simulation of cyclic displacement relative to cross displacement of belts is suggested. The displacement is created by forced cocking of joint of the upper bench contour. The study procedure and applied equipment are described. The physical ‘observation’ method of relative rest and sliding zones of belts is suggested. This method is based on capturing temperature difference at entry and exit points of the zones which is produced through the implementation of the principle of belt dry friction within the specified zone. Experimental confirmation of the existence of relative rest and sliding zones in the contact area of so called ‘load’ and tractive belts is obtained from the studies. Experimental confirmation of the hypothesis on sequencing of these zones formation in the contact area of belts is obtained as well. The significance of influence of probable installation faults on tractive ability of belt conveyor intermediate drive is shown in practice. There are the findings regarding the need of taking into account the stated phenomenon when designing belt conveyor. |
|
Improving the safety of operation mobile transport and technological machines with manipulators when working with outriggers |
Author : Lagerev I.A., Lagerev A.V. |
Abstract | Full Text |
Abstract :A new design of the outriggers for mobile transport and technological machines with manipulators was developed.
A new type of a outrigger allow to increase the overall stability when manipulator is working. The main support complemented by an anchoring device for the counteracting for machine overturning and shear service loads. The working element of the anchor device is inserted into the base surface at an angle. This ensures the formation of stress fields between the main support and anchor device. The FEM-simulation confirm the effectiveness of new outrigger design. It is theoretically found that working on the anchor device trying to escape from the base surface. Its front surface is consistently crack the soil by the rotating displacement of its adjacent layers along lines that would lead to the formation of the characteristic buckling of originally flat surface. The main support is counteracting for this process. Thus a second shear direction (perpendicular to the first direction) is create and significant increase of additional holding moment for 10..40 % (depending on base chassis). If angle between anchor device and base surface is 30…45 degrees the maximum efficiency will be obtained. |
|
About the approach to determining the indicator and constructing the scale of evaluating the protection of a dangerous production object |
Author : Rybakov A.V., Ivanov E.V., Sedov D.S., Ovsyannikov R.E. |
Abstract | Full Text |
Abstract :The article presents an approach to determining the values of the protection index of hazardous industrial facilities exposed to shock-wave action. The approach is based on energy methods. A geometric interpretation of the definition of the values of the protection index is given, for the main cases of destruction. The algorithm for grading the conditional security scale for a specific hazardous production facility is presented using a numerical experiment in the SolidWorks Simulation program. The obtained values of the indicator are applicable to the development of engineering and technical measures of civil defense, with a quantitative evaluation of measures that increase the stability of the functioning of economic objects. |
|
The effect of topography on the choice of optimal step intermediate supports along the line of the cable metro |
Author : Lagerev A.V., Lagerev I.A. |
Abstract | Full Text |
Abstract :In article was formulated and solved the problem of conditional nonlinear optimization of the distance between intermediate supports during the design of the cable metro lines in highly urbanized environment, taking into account not the horizontal surface of the terrain. The optimization problem involves a single-criterion objective function that expresses the cost of construction of the cable metro line (total cost of intermediate supports and their foundations, traction and carrying steel cables and technical equipment). The specified objective function subject to minimization by finding the optimal combination of the distance between intermediate supports and tension carrying ropes with accounting constructive, modal, structural and planning constraints in the form of nonlinear inequalities. When constructing the objective function were considered three possible forms sagging of carrying ropes, which can be implemented for various values of the efforts of their tension. Analysis was done of the influence of the angle of the longitudinal slope of the surface relief along the line of the cable metro on the value of the optimal distance between intermediate supports depending on the design and cost of intermediate supports and at the cost of 1 km line of the cable metro. Quantitative calculations showed that with the increase of the longitudinal slope of the surface construction cost also increases with nonlinear increasing rate. The dependence of the cost of 1 km of line underground cable metro from the parameters of the relief is of extreme character with a pronounced minimum at small angles of inclination of the terrain surface about 3…60 degrees. The position of the minimum is quite stable and only slightly changes when enough significant change in the cost of intermediate supports and installed on them technological equipment. The most effective conditions for the construction of the cable metro is the terrain with considerable differences in altitude along the length of the route of transport: only if the surface inclination of more than 50…60 degrees cost of 1 km line starts to exceed the cost of 1 km line laid along a strictly horizontal surface. At small angles of inclination of the surface (less than 6…8 degrees) to minimize the cost of construction of the cable metro line requires more frequent installation of intermediate supports. However, despite the possibility of building a lower and cheaper supports, the observed increased values of the cost of 1 km of optimum option of the line. At large angles of inclination of the surface a need for a more rare setup higher intermediate supports. Within the tilt angle 10…60 degrees the range of variation of the optimal step is small enough, amounting to no more than ±10 % from the value of the step at an angle of inclination of the surface 10 degree. In the range of small angles of inclination of the terrain surface (3…6 degrees) observed abrupt changes in the basic technical and economic characteristics of the cable metro lines. This is due to the change of the forms sagging of load-bearing ropes. The increase in the number of supporting ropes has a very small economic effect (within 4 %). It does not change the optimal characteristics of such line, as a step of the installation and the height of intermediate supports, shape and sagging boom carrying ropes. However, the significantly reduced diameter of the supporting rope and the horizontal force tension. The increase in aggregate strength of carrying ropes provides a directly proportional increase in the optimal step installation of intermediate supports and leads to a marked decrease in the cost of construction of the cable metro lines. At the height of intermediate supports and the horizontal force of the tension carrying ropes of their aggregate strength influence practically does not, however, leads to a significant reduction in the required diameter of the supporting ropes. It also has a positive effect on reducing the cost characteristics of the construction cable metro line. The capacity of the line cable metro has a significant impact on the optimal values of some of its basic technical and economic characteristics, in particular, the cost of 1 km line, the step to install intermediate supports, tension and diameter of the supporting ropes. Its increase is possible by increasing the allowed speed passenger cabins and (or) their capacity and quantity. In all these cases, increasing capacity causes the increase in the cost of 1 km of line and the reduction step of the installation of intermediate supports. The degree of influence these areas of increasing capacity is not the same, which suggests the presence for the given value of the theoretical capacity of an optimal combination of speed, capacity and number of passenger cabins, which will be achieved the greatest technical and economic effect during the construction of the cable metro line. |
|
Mathematical model of failure the drives suspensions of the conveyor with suspended belt and distributed drive at jamming rollers |
Author : Tolkachev E.N. |
Abstract | Full Text |
Abstract :The article is devoted to the topical issue, which is related to simulation of the failures of drives suspensions of the conveyor with suspended belt and distributed drive. A mathematical model of the failure of individual drives of suspensions due to the jamming of the rollers has been developed. Dynamic characteristics of the basic version of a conveyor with suspended belt were simulated. |
|