Faculty of Mechanical Engineering

The paper discusses optimizing of centre differential heavy truck wheel without reductions. Under optimization in this case is meant the differential type customizing cabinet designed for easy gear to withstand heavy load of a new gear. Critical structural adjustment of high-voltage areas must be such that tensions are reduced. The basis for this optimization is the result of task solution by finite element method.

The presented paper describes characteristic entities in PhotoStress method-isoclinic fringes, singular points, isostatic lines, and isochromatic fringes. These entities are used in PhotoStress method to visualise and quantify deformation and stress fields of various photoelastically coated structural elements.

In the paper we show the possibilities of physical modeling in Matlab/SimMechanics on a simple mechanical model of two link manipulator. We deal with its direct and inverse dynamics. Considering direct problem we investigate mechanical movement of the robot under the action of given forces and moments. As regards the issue of inverse motion we identify forces which cause a prescribed motion of the effector. Both problems are solved using block diagrams in Simulink and SimMechanics. Results are presented graphically.

The paper deals with analysis of rectilinear motion of the snake robot. Considering that snake robot locomotion is based on friction forces between robot and its environment, the basic friction models are introduced. For study the experimental snake robot LocoSnake is used. At first, by mechanic laws the propulsive forces affecting segment of snake robot are determined. By means of mathematical analysis the average velocity of snake robot is derived. Since the number of snake robot segments has influence on robot average velocity, the optimal nu mber of segments for maximu m velocity is derived. In the next section the influence of dry and viscous friction on moving segment are described. At last the experimental analysis of three kinds of surfaces are done, namely dry friction, viscous friction using oil and viscous friction using lubricant. The measurements by means of measuring I/O card MF624 was done. In the conclusion the differences between these surfaces are described and discussed. The contribution of the paper is determination of influence of surface change on the snake robot rectilinear locomotion.

The presented paper demonstrates the application of drilling method in the analysis of residual stresses on the transverse beam of a casting stand. In the initial stage of the analysis the determination of strains was done for individual steps of drilling in the area which was determined by means of numerical analysis. The drilling was carried out gradually by 0,5 mm up to the depth of 5 mm, while the diameter of the drilled hole was 3,2 mm. During the analysis we used the drilling device RS-200, strain indicator P3 and SGD 1-RY21-3/120. The paper presents the development of residual stresses throughout the depth of the drilled hole which were determined according to standard ASTM E837-01, by means of integral method, power series method and by means of Power Series method.

The p aper determines the range and form of a surface layer of a spheroid cast iron founding. It presents proofs of the possibility to form an operative surface of a product in the range of an intermediate surface layer of the cast. Based on research and experience, one has stated that the hardness spread and structures in cross sections of the wall of a cast are the most representative parameters determining the range of the surface layer of the iron cast.

The presented paper aims at the analysis of stress fields which occur while applying loads to a photoelastically coated notched sample. The analysis was done by means of PhotoStress ® method using reflection polariscope and digital video camera. On the notched sample subject to loads by eccentric tension we determined the differences of principal normal stresses in specified point at loads 3 kN, 4.5 kN, 6 kN, 9 kN and 12 kN. In addition, we determined the value of principal normal stress at the edge of the sample during load of 12 kN which was later compared with numerical solution in programme SolidWorks. On the photo elastically coated sample we observed maximum elongation of the coating, too. As regards maximum elongation of applied photoelastic coating PS-1A, the manufacturer states the value of 5%.

Residual stresses exist in the material as a result of the manufacturing process; do not occur due to forces on the object in use. The residual stress analysis is very important because with early detection it is possible to prevent an object from failure. Nowadays there are several methods for the measurement and determination of residual stresses. The article deals with the semi-destructive Ring-core method, which is not used in Central Europe. Information given by this article will be interesting for the reader since the article contains a short introduction the history of Ring-core method and application of the strain gage on the surface of specimen as applied for Ring-core method.

The paper is dedicated to mathematical theory of elasticity and its relevant methods as applied for determination of plane stress state for the purposes of verification of experimental values which were determined using PhotoStress ® method as applied for chosen samples. The paper further deals to a great extent with Airy biharmonic function as regards plane stress state in the samples with centrically placed round holes. The introductory part of the paper includes basic algorithms for solving the problems of mathematical theory of elasticity followed by descriptions of Airy biharmonic stress function in Cartesian and polar coordinates. In further parts of the paper were derived equations for the calculation of radial, circumferential and shear stress in samples with centrically placed round holes. Calculations are included in a single part of the paper together with input algorithms for calculations of radial, circumferential and shear stress. The algorithms were performed using the syntax of programming language Matlab in MATLAB/Simulink. Subsequently, the results of radial and circumferential stress calculations were depicted as 2D pictures similar to experimental samples with visualised stress functions. These were later used for the verification of values determined through an experiment.

The paper determines the range and the form of the surface layer of the spheroid iron cast. It presents the possibility of forming the surface layer of the mold of the exploitation surface of the final product in the range of the transverse section.

The paper presents latest means of stress state determination in structure parts while taking advantage of isolines' field. The field is scanned photographically and examined through computer technology. For such purposes, our department has designed and tested assistance computer programmes Photoelast and PhotoStress.

dean for development, external and internal relations. He is author of 9 monographs, 9 university textbook, special book publications, 12 university notebooks and more than 300 publications in journals and conference proceedings at Slovakia abroad. He is author of important projects and engineering works. He received several prizes at home and abroad. He received three honorary Doctor Honoris Causa (DHC) including two from foreign universities for the development of applied mechanics and mechatronics. doc. Ing. Ján Jadlovský, CSc. works at the Department of Cybernetics and Artificial intelligence of Technical University in Kosice as a pedagogue. He is a graduate of Technical University in Kosice, Faculty of Electrical engineering. In terms of pedagogy he focuses on the issues of proposal and implementation of distributed systems that control production processes. In his science-research based activities he is oriented towards distributed control systems, image recognition, complex functional diagnostics of single purpose regulators, diagnostics of production control systems, creation of information and control systems with application of the latest information technology. He is a chief executive of company KYBERNETIKA, s.r.o., Kosice that is oriented towards design engineering, implementation and operation of production and diagnostic systems in the electrical engineering, mechanical and metallurgical production.

The paper is dedicated to the examination of stress states of a rotating body which occur due to centrifugal forces. In order to determine stress and stain distribution, photoelastic PhotoStress method was applied and a measurement device-polariscope LF/Z-2 was used. The sample under examination was subjected to loads of various magnitudes and, subsequently, recorded with a photographic device. For objective evaluation of detected results, the object under examination was modelled and simulated in programme SolidWorks 2012.

Considering the title of this paper-"Application of Photostress method in stress analysis of structural elements under consideration of centrifugal force effect"-it can be assumed that PhotoStress method can be applied in experimental mechanics when analysing stresses and deformations of bodies in motion. The purpose of this paper is to introduce and identify photoelastic phenomena, specify dynamic stress analysis based on PhotoStress method and experimental analysis of deformation and stress fields of the rotating sample by means of PhotoStress method. The verification of solution accuracy is done through final comparison with a simulation programme.

This paper provides a description of the basic principles and procedures that can be found in strain measurements by means of an experimental method known as the digital image correlation (DIC) while using the correlation system Q-400 and the evaluation software Istra4D. The second part of the paper includes the application of DIC method in strain measurements on a sample made of a PS-1A photoelastic material while using the correlation system Q-400.

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights  Novel procedure to verify modelling in terminal ballistics of steel armours  Sufficient ballistic data with several bullet/plate interaction conditions  Calibration of constitutive and failure models using optical methods  3D modelling of bullet/target interaction using Solid and Solid/SPH conversion algorithm  The methodology satisfactorily verified and evaluated the models and FE methods

The paper deals with the connection between the issue of rectification of the structural system and the corresponding experimental and related statistical analysis of stresses. The solution was demonstrated in the example of replacing the aboveground gas pipeline with an underground solution. During the implementation of landscaping for the underground solution, there was a risk of damage to the existing structure. Due to the specific problems in stress analysis based on strain gauge measurements, especially with regard to the narrow range of gas pressure as the primary input quantity, the obtained data had to be subjected to complex statistical procedures. Several linear and non-linear regression models were compiled and subjected to normality, homoscedasticity, and autocorrelation tests. The data obtained in this manner ruled out the possibility of limited state occurrence on the existing structure and, in conjunction with other information, enabled the successful completion of th...

František Trebuňa, Dr.h.c. mult. prof. Ing. CSc. is a professor of applied mechanics, Head of the Department of Applied Mechanics and Mechatronics and Dean of the Faculty of Mechanical Engineering. He is author of 10 monographs, 12 university textbook, special book publications, 12 university notebooks and more than 300 publications in journals and conference proceedings at Slovakia abroad. He is author of important projects and engineering works. He received several prizes at home and abroad. He received three titles Doctor Honoris Causa (DHC) including two from foreign universities for the development of applied mechanics and mechatronics. Peter Frankovský, Ing. PhD. He is a senior assistant on Department of Applied Mechanics and Mechatronics. In 2010 he received PhD. in the field of applied mechanics. He works on scientific and research projects on the department and publishes the results in journals and conference proceedings at Slovakia and abroad. He made remarkable work on the building of laboratories and on publication of monographs and university textbook at the department. Jozef Bocko, doc. Ing. CSc. is an associated professor of applied mechanics on the Department of Applied Mechanics and Mechatronics, vice-dean of the Faculty of Mechanical Engineering. He is author of 1 monograph, 2 university textbooks and more than 90 publications in journals and conference proceedings at Slovakia and abroad. His research interests are oriented to the field of the finite element method, shell theory, nonlinear mechanics and application of Lie group theory in mechanics. He worked on several grant projects and research works for practice. Miroslav Pástor, Ing. Ph.D. He is a senior assistant on the Department of Applied Mechanics and Mechatronics. In 2008 he received PhD. in the field of applied mechanics. He works on scientific and research projects on the department and publishes the results. He made remarkable work on the building of laboratories and on publication of monographs and university textbook at the department.