

Articles
by
K. Syzrantseva 
Total Records (
5 ) for
K. Syzrantseva 





V. Syzrantsev
,
K. Syzrantseva
and
A. Pazyak


The study considers the problem of loading capacity calculation of bevel precessional gear for pipeline valve drives. By nowadays spiroid gear and worm gear are the basis for industrial engineering of gearboxes. These gearboxes have a lot of disadvantages such as a low efficiency, significant starting torque and low reliability in cold temperature operating conditions. Researchers propose to use gearboxes based on bevel precessional gear. Bevel precessional gear is one of the progressive types of gears with a small shaft angle. Bevel precessional gears allow to increase the loading capacity, reliability and durability of gearboxes to reduce their cost and mass and dimension characteristics and to improve their efficiency and performance criteria. The study consider the problem of determination the loading capacity by the transmitted torque considering multiple contact of teeth and fixed value of the maximum contact stress allowed by the pinion and gear materials. Researchers solve the inverse problem of loading capacitytransmitted torque is calculated at a fixed number of tooth pairs in contact. The results of studying the bevel precessional gear enable to implement original methods of evaluation its loading capacity based on contact stress. 




V. Syzrantsev
and
K. Syzrantseva


The study considers the durability estimation task of details with complicated geometrical shape working in random regime at operation. The analytical dependences for stressstrain condition calculation of machines part and units do not exist, therefore estimation of the stresses and displacements of such objects is possible to carry out only by computer simulation with the help of numerical methods: Finish Element Method (FEM). External loads to details (pressure and temperature) are random values and generally aren’t described by known laws of distribution. Researchers have developed the original algorithm for estimation of probability of nofailure operation of details based on use of the apparatus of nonparametric statistics. Adjustment of nonparametric generators of random numbers is realized by methods of nonparametric statistics in accordance with real samples of pressure and temperature. As a result of realization of multiplefactor, computer experiment for calculation the stressstrain condition of detail under random loading the functions approximating the stress variation in dangerous points depending on the loads level are determined. On the basis of these functions, the estimation of probability of nofailure operation in all dangerous points of a detail is carried out. The algorithm developed by researchers is shown on the example of durability estimation (probability of nofailure operation) of the body of wedge valve KZ13010100. 




K. Syzrantseva
,
V. Arishin
and
M. Dvoynikov


During welldrilling in conditions when bedding of solid rock is at shallow depth (from the first meters) there are significant vibrations of drilling string and connected equipment. In such situation when length of a drilling string is small and axial load on drilling bit is minimum, the effective device is necessary for compensation of axial pushes and vibrations. At the same time the geometrical shape of the damping element has to ensure the stability at significant excess of limit load and reliability. Warranty of shape retention at drilling depth increase (and respectively, increase of drilling string length and weight) will allow to avoid the additional roundtrip operations for extraction of the damping device. The study considers the main stages and features of computer simulation of damping elements operating at shallow depth of solid rock bedding by finite element method and also the subsequent optimization of its design which has allowed to increase a compliance from 0.815 mm and at the same time to provide sufficient strength reliability. The calculation model of the analysis and also boundary conditions for modeling of multicontact interaction of slot surfaces of damping elements is described in detail. The computer simulation allows to perform optimization of model at a designing stage. It considerably reduces costs for creation of new model of a design as excludes need of production of several natural samples and their bench testing for durability verification. 




K. Syzrantseva
and
A. Tarasov


The stuyd considers the problems arising in the process of unloading cement with vehicles on the example of OAO “Tyumenskaya Domostroitelnaya Kompaniya”. Modeling of the main parameters of the cement unloading system based on the Queuing theory has been performed. Functional relationships between the mean vehicle queuing time, the number of silos and vehicle unloading time have been built. It has been shown that with the number of silos equal to three the vehicle queue will continuously grow. The reason for this reduction of service channels is emergency shutdowns caused by equipment failure. As the operating experience shows transitions of metal pipes are mostly exposed to development of fatigue cracks. To identify the most probable locations of crack occurrence it has been suggested to use original means of registration of cyclic damage in metal such as the Integral Strain Gauge (ISG). Under strain cycling the gauge material changes its physical properties and a reaction in the form of dark spots occurs on its surface. The previously performed studies have shown that the form of the ISG reaction corresponds to the pattern of compression strain distribution. To coordinate the calculated and experimental data the ANSYS finite element package has been used in this study which allows evaluating the stressstrain state of a part. To evaluate the ISG reaction a special macros (script) in the APDL language has been developed. 





V. Syzrantsev
,
K. Syzrantseva
and
V. Ilyinykh


The study considers developed in kinetic theory of fatigue mathematical model for forecasting of stresscycled machine parts lifetime with specified probability of nondestruction. The results processing of samples fatigue tests is carrying out on a base of this model. Two parameters of this model: tensile strength and number of cycles before upper inflection point of lowcycle fatigue curve, related with tensile strength by nonlinear dependence are random values with unknown distribution laws. In that way left limits of confidence intervals of lowcycle fatigue curve, corresponding to specified probability (15%) of samples nondestruction used for forecasting of its lifetime are impossible to calculate. Researchers propose the original algorithm for model parameters determination of fatigue curve passing through any experimental point. Using this algorithm it is possible to calculate during computer modeling the set of fatigue curves. Obtained set of fatigue curves allows generating the random sample the number of cycles before destruction, for any fixed level of actual stress. This random sample is necessary for calculation of its quantile estimation at plotting of limits of confidence intervals. For regeneration of unknown density function of distribution this random value authors use mathematical apparatus of nonparametric statistics ensuring the task decision independently of complexity distribution law of researched random value. The results of developed algorithm realization are illustrated on example of limits of confidence intervals determination for results of lowcycle fatigue test of flexible pipes samples made of HS80 steel. 





