Modern Machinery (MM) Science Journal, December 2015

VIBRATION DIAGNOSTICS OF ROLLING BEARINGS USING THE TIME SERIES ANALYSIS

DAVID KUTALEK, MILOS HAMMER
Keywords: decomposition model | time series | vibration diagnostics | Rolling bearing

Rolling bearings are an important part of most machines with rotating parts. Therefore, their technical diagnostics is an essential condition for ensuring the safe operation of the machine. This article focuses on the assessment of the condition of bearings using one of the methods of technical diagnostics - vibration diagnostics. In our case it is determination of the value of diagnostic variables of r (…)

SYSTEM APPROACH TO DETERMINATION OF RESULTING GREEN HOUSE GAS EMISSIONS OF ENGINEERING PRODUCT

KRBALOVA MARIA, BLECHA PETR
Keywords: Life Cycle Assessment | Energy Consumption | cast iron | carbon dioxide emissions

Recently, it has been possible to observe toughening of requirements to reduce environmental burden and environmental profile of products. While the first requirements were rather general, in the course of time they have toughened and focused on spheres that most considerably affect the environment, namely, on energy-related products. According to high energy consumption in the industrial sector, an inc (…)

A DESCRIPTION OF METHODS AND TECHNIQUES OF SAFETY CULTURE RESEARCH

IRINA FEDORYCHEVA, MILOS HAMMER
Keywords: questionnaire | ethnographic research | sociometry | Delphi method | safety culture

According to the analysis of disaster investigation, written safety plans can be effective, but its insufficient condition for maintenance optimal safety level. It is also necessary to ensure creating a true safety culture. As reported by S. Mohamed (2005), this fact highlights the need not only to better understand the role played by the organizational and behavioral variables, but also to measure thei (…)

A DESCRIPTION OF SAFETY TRIAD MODELS OF SAFETY CULTURE AS A TOOL IN HUMAN PERFORMANCE RESEARCH

IRINA FEDORYCHEVA, MILOS HAMMER
Keywords: human performance | organization culture | reciprocal determinism | safety culture model

The human factor plays a decisive role in most accidents, but the problems caused by them are still unresolved. Understanding safety culture will help the industry to allocate safety resources and improve occupational health and safety performance. The paper presents an overview of the main existing triad models. The models in this paper can be used to illustrate components of the system, psychological (…)

OPTIMIZATION OF SNAP-FIT DESIGNS WITH RAPID PROTOTYPE TECHNOLOGY SUPPORT

"MARTIN SEIDL, JIRI HABR, JIRI BOBEK, LUBOS BEHALEK, PETR LENFELD"
Keywords: plastics parts | assembling | demountable joints | nap-fit

This article is focused on the design of demountable joints that have to meet high safety requirements. In total two snap-fit geometries were designed in two, respectively three modifications. These constructional solutions could be divided into two categories (easily deformable mounting elements and mounting elements deformable with difficulty). Several evaluating criteria were chosen. The most importa (…)

ASPECTS OF PRESSURE SEWERAGE SYSTEM DESIGN

JAN RUCKA, TOMAS SUCHACEK, JIRI KOVAR, ONDREJ ANDRS
Keywords: pressure measurement | flow analysis | back-flow valve | research | hydraulic analysis | waste water | low pressure sewer

The article deals with some aspects and uncertainties of the design and operation of low pressure sewer systems. The most frequently used types of pumps are compared in the text with respect to the design parameters and impact to the hydraulic analysis of the pressure system. Also different methodologies of estimation of design flow are compared with the flow that was measured on the real low pressure s (…)

ERROR MOTION ANALYSIS OF MACHINE SPINDLE UNDER LOAD

JOSEF KNOBLOCH, TOMAS MAREK, ZDENEK KOLIBAL
Keywords: spindle modelling | load unit | measurement | spindle error

The present paper deals with a novel approach to the analysis of machine tools under load; it identifies the parameters of machine tool spindles simulating a real cutting process. The main focus of the paper is on evaluation of synchronous and asynchronous error motions and their dependency on spindle speed and load. To investigate the errors, a hydraulic load unit is used. This unit exerts a uni - or b (…)

QUALITATIVE MODEL OF PERFORMANCE SHAPING FACTORS IN HRA

LEISAN MUKHAMETZIANOVA, LUBOS KOTEK, MIRKO DOHNAL
Keywords: qualitative model | performance shaping factors | human error | human reliability analysis

A lot of Human Reliability Analysis (HRA) methods calculate human error probability (HEP) based on different performance shaping factors (PSF). In calculating HEP, interdependency is generally ignored or addressed through varying parameters in linear or loglinear formulas [Groth 2009]. These dependencies could be more precisely represented by a qualitative model of PSF relationships. The aim of this pap (…)

EXPERIMENTAL INVESTIGATION OF LUBRICATION FILM FORMATION AT START-UP OF SMOOTH SURFACES

PETR SVOBODA, DAVID KOSTAL, IVAN KRUPKA, MARTIN HARTL
Keywords: non-conformal contact | start-up | Film thickness | transient | EHD lubrication

Many machine components are operated under transient conditions that can cause the lubrication film breakdown. In such a case, surface interactions can lead to wear and significantly reduce life of these components. Start-up of the machine components to the relative motion is one of the transient phenomenon where surfaces are not fully separated by a continuous layer of lubricant. This article summaries (…)

FILM THICKNESS MAPPING IN LUBRICATED CONTACTS USING FLUORESCENCE

"DAVID NECAS, PETR SPERKA, MARTIN VRBKA, IVAN KRUPKA, MARTIN HARTL"
Keywords: compliant | fluorescence | Film thickness | elastohydrodynamic | isoviscous

The present paper presents experimental method for film thickness mapping inside the contact of two bodies. Despite extensive experimental research in the area of contacts of rigid bodies, little is known about the film formation when at least one of the bodies is compliant. This is due to limitations disabling the usage of conventional methods. In present study, mercury lamp induced fluorescence is dev (…)

MEASUREMENT-INDUCED WEAR OF ALUMINIUM ALLOY PARTS

ROBERT JANKOVYCH, MARTIN WEIGL, JAN KUR
Keywords: measuring in automotive | Dutch diamond | black diamond | measuring probe | dynamic measuring

This article presents influence of measuring probes on a dynamically measured part made from automotive aluminium alloy. Dynamic measuring (during rotation or translation) is limited not only by scanning rate of measuring sensors and processing devices, but also by physical and metrological attributes of measuring probes, which are in direct contact with the measured part. Current trend in automotive in (…)

LASER MARKING OF METAL MATERIALS

LYDIA SOBOTOVA1, PETER DEMEC2
Keywords: material | marking system | laser technology

The contribution deals with the implementation of new information from the area of laser marking processing. The marking of various types of metal and non-metal materials are very actual topic of these days. The focus is on the production technical aspects of laser engraving and the introduction of processing strategies. Less attention is paid to the complex chemical process that can be observed when us (…)

SOFTWARE QUALITY CONTROL WITH THE USAGE OF IDEAL AND TMMI MODELS

PETR BRIS, MICHAL FRANTIS, MONIKA KOLKOVA
Keywords: competitiveness | modelling | TMMi | software testing | quality control

Our work focuses on process of software testing with the regard on his control and quality securing. Theoretical part explains basic terminology used later in our work. It explains the terms such as quality, process control management or software. Later our work describes software testing in relation with methodology of software development, quality improvement of process testing with the usage of mode (…)

MANUFACTURING MULTI-AGENT SYSTEM WITH BIO-INSPIRED TECHNIQUES: CODESA-PRIME

LUKAS DURICA, BRANISLAV MICIETA, PETER BUBENIK, VLADIMIRA BINASOVA
Keywords: CODESA-Prime | biologically inspired techniques | advanced industrial engineering | sustainable production | multi-agent system

This paper deals with the multi-agent manufacturing system with application of bio-inspired techniques and new approaches to the development trends of advanced industrial engineering (AIE) in energy efficient manufacturing. This integration represents a sustainable development so that more effective use of natural and energy resources is achieved and energy costs are reduced. The new solution of referen (…)

CONTRIBUTION TO MAINTENANCE ISSUES IN COMPANY PRACTICE

HANA OPOCENSKA, MILOS HAMMER
Keywords: reliability centered maintenance | total production maintenance | after-failure maintenance | preventive maintenance | systems of maintenance | classification of maintenance | maintenance

Currently, companies are more and more interested in the issues of maintenance. The present article provides basic information about maintenance, describes its development stages; it also refers to the classification of maintenance and analyses the maintenance systems used in practice. Moreover, some modern approaches to maintenance are presented and supported by selected specific cases from engineerin (…)

IMPACT RESISTANCE OF LATTICE STRUCTURE MADE BY SELECTIVE LASER MELTING FROM AlSi12 ALLOY

RADEK VRANA1, DANIEL KOUTNY1, DAVID PALOUSEK1, TOMAS ZIKMUND2
Keywords: AlSi12 | energy | particle distribution | impact resistance | lattice structure | selective laser melting

This article describes the impact resistance of lattice structure made by metal additive technology Selective Laser Melting using AlSi12 aluminum powder material. Powder particle distribution was analyzed for verification of distribution and shape of particles. Samples of lattice structure are consisted of three segments. The main part – lattice structure is made from repeated Body Centered Cubic (BCC) (…)

BORE QUALITY OF SHOTGUN BARREL BLANKS

ROBERT JANKOVYCH, MILOS HAMMER, MATEJ HARCARIK
Keywords: radial forging | barrel blanks | shotguns | firearms | surface metrology | surface texture

This paper provides a novel manner of shotgun barrel bore surface texture specification. The current state of shotgun barrel blank bore surface texture specification and measurement is analyzed. Comparative measurements of samples with good and inferior surface quality are used to demonstrate the shortcomings of current specifications. In seeking improvement, six profile parameters are evaluated and the (…)

CONTRIBUTION TO DIAGNOSTICS OF ASYNCHRONOUS MOTORS

VLADIMIR VESELKOV, MAXYM ZHALO, ANDREI TURYGIN, MILOS HAMMER, ROBERT JANKOVYCH
Keywords: angular misalignment | fuzzy subsystem | fuzzy expert system | expert system | electric drive | asynchronous motor | diagnostics

Asynchronous motors are a frequent power member of electric drives. In engineering practice their reliability is important. Although the available literature indicates a high reliability of these machines, in many applications reliability needs to be monitored and evaluated. A significant role in this process occupies technical diagnostics. Engineering practice knows a considerable amount of diagnostic (…)

VIBRATION DIAGNOSTICS ON A HYDRAULIC ROTATOR

TOMAS BUDIK, ROBERT JANKOVYCH, MILOS HAMMER, TADEAS LIPUS
Keywords: vibration diagnostics | zones boundary | rotator

This article focuses on the philosophy of vibration diagnostics on an Indexator hydraulic rotator. Following the analysis of the construction and machine functions, defect frequencies are calculated. The vibration measurement system for the technical diagnosis of the rotator were then designed. According to the vibrations measured on the GV6 rotator, limits for a new machine are proposed (the boundary b (…)

MACHINE TOOL HEALTH AND USAGE MONITORING SYSTEM: AN INTITIAL ANALYSES

LUDEK JANAK, ZDENEK HADAS
Keywords: industry 4.0 | reliability | sensors | HUMS | usage monitoring | health monitoring | Machine tools

In order to be competitive on a present-day machine tool market, it is needed to produce a high quality, highly reliable systems with low operating and overall lifecycle costs. Health and usage monitoring systems are one of the promising technologies which are being developed to support this effort. The health and usage monitoring systems have been widely employed in the aerospace branch where the condi (…)

PREPARATION AND CHARACTERIZATION OF TiO2 THIN FILMS FOR UV SENSOR

"LIDIYA BEDIKYAN1, STOIL ZAKHARIEV1, PAVEL KEJZLAR2, LUKAS VOLESKY2, ARGARITA ZAKHARIEVA1, NIKOLAY PETKOV1, PETR LOUDA2"
Keywords: UV sensor | surface analysis | band gap | spectral characteristics | titanium dioxide

Nanosized TiO2 thin films were deposited by conventional vacuum thermal evaporation and triode-cathode sputtering of Ti on silicon and quartz substrates. To form TiO2 a high temperature annealing of the Ti films was carried out in the range of 450÷800 ºC. The optical properties of TiO2 were studied by measuring UV-VIS transmittance spectra and the indirect band gap was evaluated. Scanning electron micro (…)

STUDY OF SUSPENSION CHARACTERISTICS BY USING FLEXIBLE SUBFRAME

TOMAS VRANA1, JAN KOVANDA2, JOSEF BRADAC3
Keywords: hyperworks | toe angle | camber angle | subframe flexible model | MBS model | single-axle suspension

This paper analyzes the impact of subframe flexibility of single-axle suspension on elasto-kinematic properties of axles. Geometrical parameters of the suspension, such as camber angle β and toe angle α and their change upon vertical movement of the wheel or when exposed to longitudinal and lateral forces affect very significantly driving properties of the vehicle. Using HyperWorks simulation software t (…)

STUDY OF CHANGES FOR SELECTED FIRE PARAMETERS AT ACTIVATION OF DEVICES FOR SMOKE AND HEAT REMOVAL AND AT ACTIVATION OF FIXED EXTINGUISHING DEVICE

JIRI POKORNY, MARIANNA TOMASKOVA, MICHAELA BALAZIKOVA
Keywords: CFAST | active fire safety devices | change of conditions | course of fire

This article demonstrates changes of the selected parameters of fire development using a fire model, which is applied in the case of chosen fire example (simulated fire). There is analysed an influence of the active fire-safety devices on the fire parameter changes (in the Part No. 3 – Discussion of Results). The main purpose of this article is to present a basic importance of the active fire-safety de (…)

IMPROVEMENT OF HEAVY MACHINE TOOL DYNAMICS BY PASSIVE DYNAMIC VIBRATION ABSORBER

TOMAS BREZINA1, LUKAS BREZINA2, JAN VETISKA3
Keywords: optimization | dynamic vibration absorber | state space LTI | vibrations | Machine tool

The article deals with evaluation of frequency responses of heavy machine tool for different attachment places of dynamic absorbers or dynamic vibration neutralizers in order to substantially suppress vibrations occurring during a machining process. The approach is based on methodology utilizing a multi-body model of a machine tool with flexible bodies in linear state-space form with added structure rep (…)

EXPERIMENTAL ANALYSIS ON MACHINABILITY OF ALUMINUM ALLOY USING WEDM TECHNOLOGY

KATERINA MOURALOVA, JANA DVORAKOVA, JAROMIR DVORAK, JIRI KOVAR, ZDENEK KARPISEK, PETRA SLIWKOVA
Keywords: Analysis of variance ANOVA | DOE | analysis of machinability | machining of Aluminium alloys | WEDM

Wire electrical discharge machining (WEDM) is unconventional method commonly used for manufacturing of components with difficult shapes or profiles. It is very useful for machining very small – micro components with high dimensional accuracy and quality of surface finish. This technology allows even cutting of very hard materials, provided they are conductive. First part of this paper deals with machin (…)

THE APPROACHES OF ADVANCED INDUSTRIAL ENGINEERING IN ENERGY EFFICIENCT MANUFACTURING

BRANISLAV MICIETA, VLADIMIRA BINASOVA, MICHAL HALUSKA
Keywords: cost optimization | advanced industrial engineering | sustainable production | energy efficient manufacturing

This paper deals with new approaches to the development trends in the advanced industrial engineering (AIE) in energy efficient manufacturing. This integration represents a sustainable development so that more effective use of natural and energy resources are achieved and energy costs are reduced. The progress of energy efficiency improves the competitiveness of manufacturing enterprises and reduces the (…)

QUALITY OF DIMENSIONS ACCURANCY OF COMPONENTS AFTER WEDM DEPENDING ON THE HEAT TREATMENT

KATERINA MOURALOVA, JIRI KOVAR
Keywords: steel X210Cr12 | kerf width | heat treatment | electrical discharge machining | WEDM

The main purpose of this paper is to examine the gap width of the wire cut after WEDM depending on the heat treatment of machined material - high-alloy steel X210Cr12. This steel is usually used for the production of cutting tools. Cutting gap occurs during the discharge between the tool electrode and the machined material. This discharge causes melting of microscopic particles of the workpiece; the par (…)