Teaching classical calculation methods

Author(s):  
Andrei Buzin
1999 ◽  
Vol 29 (3) ◽  
pp. 179-188
Author(s):  
Andrei Buzin

1996 ◽  
Vol 118 (2) ◽  
pp. 216-220 ◽  
Author(s):  
J. D. Olivas ◽  
K. Ravi-Chandar ◽  
J. Bustillos ◽  
L. Craigie

A study was carried out to evaluate the buckling of anisotropic cylindrical vessels subjected to external pressure. The cylinders were fabricated with filament-wound glass fiber in a vinyl-ester resin matrix and tested using a novel experimental procedure. Characteristic response of each specimen to strain and acoustic emission were compared to the onset of buckling. The measured onset of buckling lobe formation agreed with values predicted by classical calculation methods founded on Donnell kinematic relations and antisymmetric assumptions. Also, two ASME design criteria, Section X and RTP-1, for the design of thin-walled cylindrical vessels made from fiber-reinforced thermosetting plastic, subjected to external pressure were evaluated; RTP-1 was found to be too conservative, while Section X did not provide the professed design factor of 5.


Author(s):  
А.А. СИМДЯНКИН ◽  
Л.П. БЕЛЮ

Проблема и цель. Целью настоящего исследования является оценка влияния расположения в кузове автомобиля ящиков с яблоками сорта «Айдаред», устойчивыми к повреждениям, на изменение скорости колебаний отдельных плодов в декартовой системе координат при движении транспортного средства по дорогам с различным покрытием и с различной скоростью. Методология. В качестве объекта исследований были выбраны яблоки, уложенные в стандартный ящик, размещаемый в трех положениях в кузове автомобиля «Форд Транзит». Измерения проводились на дорогах с тремя различными типами покрытий – асфальт, щебень и грунт на скоростях автомобиля, находящихся в диапазоне 20-50 км/ч. При проведении исследований использован метод замера ускорений в трех направлениях встроенным в смартфон акселерометром с установленным на нем программным обеспечением «Измеритель вибрации 1.3.6 APK», а также классические расчетные методы, позволяющие определить скорость яблока и его кинетическую энергию. Результаты. Выявлено наилучшее (с точки зрения повреждаемости плодов) расположение ящиков с яблоками – между осями автомобиля, и наихудшее – над задней осью. Приведена оценка вероятных повреждений плодов на основе расчета изменения их кинетической энергии при движении автомобиля. Определено изменение влажности плодов во времени при имитации получасовой перевозки яблок по щебеночной дороге со скоростью 20 км/ч. Установлено, что зафиксированное повышение абсолютной влажности плодов (более, чем на 10 %) существенно ускорит процессы биологического разложения, и даже дополнительное охлаждение не сможет существенно замедлить этот процесс. Заключение. На основании проведенных исследований рекомендуется избегать дорог с грунтовым и щебеночным покрытием в период их неудовлетворительного состояния, а при невозможности избежать таких участков использовать низкую скорость движения (не выше 20 км/ч), располагая ящики между осями автомобиля. Problem and purpose. The purpose of this study is to assess the efect of the location of boxes with Idared apples, resistant to damage, in the car body on the change in the vibration speed of individual fruits in a Cartesian coordinate system when a vehicle moves on roads with diferent surfaces and at diferent speeds. Methodology. Apples in a standard box placed in three positions in the body of a “Ford Transit” car were chosen as the object of the research. The measurements were carried out on roads with three diferent types of surface – asphalt, crushed stone and soil at vehicle speeds of 20-50 km/h. During the research measuring accelerations was done with the help of an accelerometer built into a smartphone with "Vibration Meter 1.3.6 APK" software installed on it. Besides the classical calculation methods allowing to determine the speed of an apple and its kinetic energy were used. Results. The best (in terms of fruit damage) location of boxes with apples is found and that was between the axles of the car, and the worst ones were above the rear axle. The estimation of probable damage to fruits based on the calculation of changes in their kinetic energy when driving a car was given. The change of fruit moisture was determined when simulating a half-hour transportation of apples along a gravel road at a speed of 20 km/h. It was found that the recorded increase in the absolute humidity of fruits (more than 10%) signifcantly accelerated the processes of biological decomposition. And even additional cooling could not signifcantly slow down this process. Conclusions. Based on the conducted research it is recommended to avoid roads with dirt and crushed stone surfaces during their unsatisfactory condition. If it is impossible to avoid such sections a driver should use a low speed (no higher than 20 km/h) placing boxes between the axles of the car.


1993 ◽  
Vol 115 (4) ◽  
pp. 711-720 ◽  
Author(s):  
H.-H. Priebsch ◽  
J. Affenzeller ◽  
S. Gran

Design analyses of crankshafts, including bearings, are necessary for both the layout of new engines and the modification of existing engines (increased power output, etc.). To improve the existing calculation systems for crankshafts and bearings, AVL has developed a new method. This method enables the coupled vibrations in the torsional, bending, and axial directions, including gyroscopic effects, to be analyzed. For simulation of multibearing effects, the bearing models consider both the hydrodynamic oil film and the stiffness of the bearing structure. The calculation of forced vibrations is carried out using the gas and mass forces acting upon the rotating crankshaft. Comparisons of calculated to measured results demonstrate the accuracy of this calculation technique. The method can be used for passenger car, truck, and medium speed engines. In this paper examples of truck and passenger car engine applications confirm the additional possibilities for the estimation of crankshaft dynamics. Also the improvement of the results obtained from the new technique compared with those from classical calculation methods is described.


2010 ◽  
Vol 652 ◽  
pp. 1-6
Author(s):  
Krzysztof Wierzbanowski ◽  
Jacek Tarasiuk ◽  
Alain Lodini

The genetic algorithm method was used in the present work as an alternative to classical calculation methods. It can be used in the situations where we search an optimal solution and a problem has many variable parameters. In this work the genetic algorithm method was applied in order to decompose the texture function into ideal components and also to optimize elastic constants by an appropriate choice of texture function. These example applications of genetic algorithm method show its potential in the field of material engineering.


Author(s):  
Simona Dragomirescu ◽  
Daniela Solomon

Classical accountancy shaped and coagulated in an informational system grafted on traditional production systems, characterized by mass productions, planning etc. The powerful concentrations and grouping, economies globalization, both as offer and as demand, the new restrictions and economical opportunities and global environment technologies lead to a redefining of enterprises’ objectives. From the well-known “quantity and productivity”, the enterprise faced a new system of objectives: quality’s increase; terms and costs decrease; productivity; flexibility. In such conditions the need of “defining new methods” appeared, the need of adapting the fundamental calculation methods, their improvement – respective the appearance of modern methods of costs calculation.


2015 ◽  
pp. 147-160 ◽  
Author(s):  
S. Bobylev ◽  
N. Zubarevich ◽  
S. Solovyeva

The article emphasizes the fact that traditional socio-economic indicators do not reflect the challenges of sustainable development adequately, and this is particularly true for the widely-used GDP indicator. In this connection the elaboration of sustainable development indicators is needed, taking into account economic, social and environmental factors. For Russia, adaptation and use of concepts and basic principles of calculation methods for adjusted net savings index (World Bank) and human development index (UNDP) as integral indicators can be promising. The authors have developed the sustainable development index for Russia, which aggregates and allows taking into account balanced economic, social and environmental indicators.


2015 ◽  
pp. 39
Author(s):  
A. L. Khomchanovsky ◽  
E. A. Fedorova ◽  
An. A. Lygin ◽  
A. Sh. Khabidov

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