Strengthening elements of steel structures for controlling fatigue fracture

The article deals with the issues of reliable operation of steel structures of mine hoisting machines. It is proposed to strengthen the “weak points” of the braking device beam structure, which will further prevent the formation and growth of cracks in the body of the metal structure. The article presents the results of examining steel structures of mine hoisting machines by the methods of non-destructive testing and the percentage of various damages is determined. The article discusses the method for controlling fatigue failure of steel structures through the use of strengthening elements to reduce their metal consumption and increase resistance to fatigue failure, while completely eliminating the use of expensive high-strength alloys

Method of restoring pivot connections cast iron bushings of heat engine with external heat supply

The article presents the results of studies aimed at developing a method of restoring cast iron bushings for pivot connections of a heat engine with external heat supply. The methods of computer modeling the stress-strain state of the pivot connections are used. To carry out computer modeling, the ANSYS program has been used, which allows simulating the stress-strain state of the kinetic pair of the pivot connection of the crank mechanism of engines with external heat supply and excluding cumbersome field tests of experimental samples. The dependence of stresses on the contact surface of the bushing on the depth of the boring in relation to its total length has experimentally been established

Use of computer simulation to establish parameters of steel structure strengthening elements

The article presents the results of computer simulation related to establishing the parameters of mine hoisting machine steel structure strengthening elements. The simulation was performed using the ANSYS computer program. The basis of this program is the finite element method therefore, selecting the type and the size of the finite element affects the calculation accuracy. There have been studied 11 computer models. The results obtained make it possible to establish the strengthening element optimal shape, size and thickness. The most optimal shape of the pad is a disc; this has a positive effect on reducing the level of mechanical stresses in the fracture zone of the beam. The strengthening element «disc pad» is used to combat fatigue failure of the brake beam structures of a mine hoisting machine. The article presents practical experience in the fight against fatigue failure of f mine hoisting machine steel structures

Strengthening elements to increase fatigue strength of mine hoisting machine steel structures

The article deals with the issues of reliable operation of metal structures of mine hoisting machines. A method has been developed that makes it possible to increase the brake device steel beam structures strength, which will further prevent the formation and growth of cracks in the body of the metal structure. It is proposed to strengthen the «weak points» in the structure to increase strength and resistance to fatigue failure with the complete rejection of using expensive high-strength alloys. To study the stress-strain state and fatigue failure of steel structures, the method of computer simulation was used. The article presents the results of studying metal structures of mine hoisting machines by non-destructive testing methods; the percentage of various damages is determined. The article discusses a method for combating fatigue failure of steel structures through the use of elements that strengthen the structure in the places of its fatigue failure

Use of computer simulation to establish parameters of steel structure strengthening elements

The article presents the results of computer simulation related to establishing the parameters of mine hoisting machine steel structure strengthening elements. The simulation was performed using the ANSYS computer program. The basis of this program is the finite element method therefore, selecting the type and the size of the finite element affects the calculation accuracy. There have been studied 11 computer models. The results obtained make it possible to establish the strengthening element optimal shape, size and thickness. The most optimal shape of the pad is a disc; this has a positive effect on reducing the level of mechanical stresses in the fracture zone of the beam. The strengthening element «disc pad» is used to combat fatigue failure of the brake beam structures of a mine hoisting machine. The article presents practical experience in the fight against fatigue failure of f mine hoisting machine steel structures

Strengthening elements to increase fatigue strength of mine hoisting machine steel structures

The article deals with the issues of reliable operation of metal structures of mine hoisting machines. A method has been developed that makes it possible to increase the brake device steel beam structures strength, which will further prevent the formation and growth of cracks in the body of the metal structure. It is proposed to strengthen the «weak points» in the structure to increase strength and resistance to fatigue failure with the complete rejection of using expensive high-strength alloys. To study the stress-strain state and fatigue failure of steel structures, the method of computer simulation was used. The article presents the results of studying metal structures of mine hoisting machines by non-destructive testing methods; the percentage of various damages is determined. The article discusses a method for combating fatigue failure of steel structures through the use of elements that strengthen the structure in the places of its fatigue failure

ТЕРМОДИНАМИЧЕСКИЕ ИССЛЕДОВАНИЯ И ОБОСНОВАНИЕ АЛЮМИНОТЕРМИЧЕСКОГО СПОСОБА ПОЛУЧЕНИЯ КАЛЬЦИЯ

To search the ways of solving the problem on decreasing the prime cost of producing metallic calcium, it is proposed to consider its aluminothermic production by the example of the CaO–Al system. The thermodynamic analysis implemented for this system showed that the aluminothermic reduction of calcium from its oxide is technically performable under a pressure of 5–10 Pa and temperature of 1200–1500 °C. It is revealed that the implementation of reduction under the residual pressure lower than 1 atm (101,3 Pa) considerably lowers the thermodynamic temperatures of reaction beginning. It is established that only three reactions, in the course of which, calcium aluminates 3CaO·Al2O3, 5CaO·3Al2O3 (12CaO·7Al2O3), and CaO·Al2O3 are formed, can be used for practical purposes. It is proposed, depending on the final state, to separate the process into the «low-temperature» one (up to 1200 °C, the calcium yield is no higher than 64,3 %) and «high-temperature» one (up to 1500 °C, up to 75 % Ca). It is planned to further confirm these data experimentally.Для поиска путей решения задачи по снижению себестоимости производства металлического кальция предложено рассмотреть процесс его алюминотермического получения на примере системы СаО–Al. Выполнен термодинамический анализ в указанной системе, который показал, что процесс алюминотермического восстановления кальция из его оксида технически осуществим при давлении 5–10 Па и температуре 1200–1500 °С. Выявлено, что проведение процесса восстановления при остаточном давлении менее 1 атм (101,3 кПа) значительно снижает термодинамические температуры начала реакций. Установлено, что для практических целей можно использовать только три реакции, в ходе которых образуются следующие алюминаты кальция: 3CaO·Al2O3, 5CaO·3Al2O3 (12CaO·7Al2O3) и CaO·Al2O3. Предложено в зависимости от конечного соединения разделить процесс на «низкотемпературный» (до 1200 °С, выход кальция не более 64,3 %) и «высокотемпературный» (до 1500 °С, до 75 % Ca). В последующем планируется опытным путем подтвердить полученные данные

Ion Sources for Energy Extremes of Ion Implantation.

For the past four years a joint research and development effort designed to develop steady state, intense ion sources has been in progress with the ultimate goal to develop ion sources and techniques, which meet the two energy extreme range needs of mega-electron-volt and 100's of electron-volt ion implanters. This endeavor has already resulted in record steady state output currents of high charge state of Antimony and Phosphorous ions: P{sup 2+} (8.6 pmA), P{sup 3+} (1.9 pmA), and P{sup 4+} (0.12 pmA) and 16.2, 7.6, 3.3, and 2.2 pmA of Sb{sup 3+} Sb{sup 4+}, Sb{sup 5+}, and Sb{sup 6+} respectively. For low energy ion implantation our efforts involve molecular ions and a novel plasmaless/gasless deceleration method. To date, 1 emA of positive Decaborane ions were extracted at 10 keV and smaller currents of negative Decaborane ions were also extracted. Additionally, Boron current fraction of over 70% was extracted from a Bemas-Calutron ion source, which represents a factor of 3.5 improvement over currently employed ion sources