Acta Mechanica Slovaca, 2014 (vol. 18), issue 2
Metrology, Its Position in Industry and Necessity of EducationEditorial, Editorial article
Miroslav Dovica
Acta Mechanica Slovaca 2014, 18(2):4
Comparison of Pressure Losses of Clean and Deposit-covered Heat Exchange Surfaces of a Natural Gas Cooler
Mária Čarnogurská, Miroslav Příhoda, Juraj Václav
Acta Mechanica Slovaca 2014, 18(2):6-12 | DOI: 10.21496/ams.2014.013 
This article discusses the pressure losses which occur on the outer and inner heat transfer surface area of natural gas coolers. An analytical method is used to determine the pressure loss on the outside of the heat transfer surface area and the development of this loss is presented depending on the thickness of coating (dirt) deposited on the fins of the heat exchange surfaces. The pressure loss inside the cooling tubes from the layer of deposition is expressed specifically as friction loss, especially the loss of local resistance and collective pressure loss. The results include an assessment of the impact of the deposited impurities on the compression...
Strength Calculations of Dual-power Path Gearing with FEM
Jacek Pacana, Andrzej Pacana, Lucia Bednárová
Acta Mechanica Slovaca 2014, 18(2):14-19 | DOI: 10.21496/ams.2014.014
The paper contains a strength analysis of gears in a dual-path gearing made of plastic. Calculations were carried out using Abaqus program by means of Finite Element Method (FEM). Due to the fact that the dual-path gearing had wheels with straight teeth, it was possible to simplify the calculations using two-dimensional models. In the carried out FEM analysis, stress distribution was determined on models of pinions and gears, paying particular attention to key points like teeth feet or their side surfaces. Conclusions obtained as a result of the analysis will make it possible to introduce conceivable changes in the structure of the designed gearing...
Proposal Hardware and Software Modules for Multi-agent System of Robosoccer
Marek Sukop, Mikuláš Hajduk, Jozef Varga
Acta Mechanica Slovaca 2014, 18(2):20-27 | DOI: 10.21496/ams.2014.015
This article describes the implementation of the basic hardware and software modules used by FME TU Robotics team in international competitions in the robotic soccer (category Mirosot).
Power Engineering of Brake System of a Heavy Duty Agricultural Motor Vehicle
Melinda Menyhártné Baracskai
Acta Mechanica Slovaca 2014, 18(2):28-35 | DOI: 10.21496/ams.2014.016
Thermal problems of brake system of a heavy duty engine are analyzed in the article. The agricultural motor vehicle is able to travel at 40 kph speed and its weight is 30000 kg. Owing to friction of brake discs, significant amount of heat is released when brake of this vehicle of large weight is applied. For the brake to operate in a reliable way, it is essential to prevent overheating.Design of brake system is described in the article. Description of experiments conducted for inspecting heating and evaluation of results are also included in it. After that, the heat released during brake application is determined. It is also discussed when the...
Methods to Expand the Speed and Load Range of Homogeneous Charge Compression Ignition Engine
Martin Šima, Peter Bigoš, Roman Tonhajzer
Acta Mechanica Slovaca 2014, 18(2):36-40 | DOI: 10.21496/ams.2014.017
A Novel Algorithm for the Calibration of Inertial/Magnetic Sensors: Application to a Body Sensor Network
Daniel Rüschen, Berno J.E. Misgeld, Saim Kim, Steffen Leonhardt
Acta Mechanica Slovaca 2014, 18(2):42-49 | DOI: 10.21496/ams.2014.018
Knowledge about the orientation of body segments is a vital source of information. It can be used to estimate human posture in a dynamic environment with multiple applications ranging from artifact or disturbance detection to rehabilitation robotics. The development and test of inertial measurement units requires calibration and a proper reference that can be provided by a motion tracking system. We present a novel approach for the fast calibration of inertial/magnetic sensors and the spatial synchronization with a reference system. The calibration procedure is tested using a Body Sensor Network-based inertial measurement unit and a Vicon tracking...
Transformation of Product Characteristics in Terms of an Integrated Management System
Lukáš Kamenický, Štefan Markulik, Juraj Sinay
Acta Mechanica Slovaca 2014, 18(2):50-55 | DOI: 10.21496/ams.2014.019
This paper introduces an approach for collecting requirements of products and an integrated management system and subsequently links them by use of organizational processes and structures. More specifically this is a unique and integrated approach for IMS, Requirement Management and product design. This approach supports organizational processes with methods and tools helping to analyze, control and primary build up and handle complex systems and the interdependencies between their comprising models from various domains within the range of integrated management systems. Duplicity or contradictions of requirements can be avoided. This approach links...
The stress state in the three-layer open conical shell during of stability loss
Edward Tertel, Piotr Kurylo, Wladyslaw Papacz
Acta Mechanica Slovaca 2014, 18(2):56-62 | DOI: 10.21496/ams.2014.020
The paper presents an analysis of stress state in a sandwich open conical shells during of stability loss. The shells under consideration consist of lightweight core layer and two face-layers which are load-carrying. The thickness of those faces is assumed to be equal, and the thickness of the core is about 80% of the whole shell thickness. The load carrying faces are made of isotropic, compressible, work-hardening materials. The core layer is assumed to be elastic, incompressible in the normal z direction and it resists transverse shear only. The shell under consideration is loaded by lateral pressure and longitudinal force. Deformation of the shells...
Preparation and Utilization of Biogas Produced from Wastes in Slovakia
Peter Horbaj, Peter Lukáč, Marián Lázár, Marta Lengyelová
Acta Mechanica Slovaca 2014, 18(2):64-69 | DOI: 10.21496/ams.2014.021
In the paper, the authors present actual situation in preparation of bio fuels from biomass in conditions of Slovakia and also some examples of utilization of produced bio fuel. There is short description of bio fuel produced from agricultural waste, from wood and from sewage treatment plant. These 3 ways are most common in our conditions.
Study of the Vibratory Behavior of Composite Plates under the Effect of Different Reinforcement Parameters
Abdelmalek Abdelmalek, Bouazza Mokhtar
Acta Mechanica Slovaca 2014, 18(2):70-75 | DOI: 10.21496/ams.2014.022
This contribution consists of the free vibratory behavior analysis of composite plates laminated; the study of the vibration in displacement of such structures rests primarily on the research of the frequencies and the clean modes, the main axis of this study is the enhancement and the discussion of the effects various geometry of plate, the reinforcement fibers orientation and the ratio orthotropic of the material on the oscillation frequencies. The choice of the model that says we have taken into consideration in the simulation, meets the objective of our study and the results are then validated by available literature results.
New Design Concept of Solutions for Dynamic Protection of Canal Lock
Jozef Kuľka, Martin Mantič, Peter Bigoš
Acta Mechanica Slovaca 2014, 18(2):76-81 | DOI: 10.21496/ams.2014.023
Water transport is an integral part of load transport system and therefore its safe functioning is necessary. At waterways the frequent obstacles are hydro-electric power plants which are equipped with canal locks to allow the canalisation of the river. To provide safe sailing of ships through such a locks without causing any damage, the canal locks are equipped with a protective system against impact in addition to other devices even in emergencies. This paper describes a proposal of a new construction of the trolley of dynamic canal lock protection as well as a design of its drive.
Influence of Vanadium Content on the Toughness and Hardness of High-alloyed Cr-Mo Steel
A. Todić, D. Čikara, B. Pejović, T. Todić, V. Mićić, I. Čamagić
Acta Mechanica Slovaca 2014, 18(2):82-87 | DOI: 10.21496/ams.2014.024
Characteristics of air hardening steel are high hardness and low impact toughness. In order to increase the impact toughness while retaining replace with the high hardness value numerous research added. One of the ways to achieve this is the alloying of specified steel with vanadium and application of appropriate heat treatment. Vanadium affects the solidification process of these alloys by narrowing of the temperature interval of crystallization. In addition, vanadium formed V6C5 carbides that block the growth of austenitic dendrites and structure makes fine-grained. Vanadium which forms V6C5 carbides is partly distributed between present phases in...