The stability of a machining process is a function of the dynamic response between the spindle and table, which varies within the machine work volume. This paper deals with computationally efficient methodology to evaluate and simulate dynamic performance of the machine tool. A position-dependent virtual model is assembled using finite element model reduced via component mode synthesis and transformed t (…)
The paper focuses on the drinking water supply with public water mains without the use of disinfectant residues in the transported water. This method of delivering drinking water can only be considered if a sufficient number of functional barriers are present in the distribution system to prevent the penetration of pollution into the transported water. One of these barriers is, for example, a good techn (…)
Materials and elements with a high melting point, including molybdenum, are suitable for high temperature physical applications and the fabrication of components such as welding electrodes or wires to be used in spark erosion wire-cut machines. The classic, or conventional, approaches to machining pure molybdenum are aptly complemented with the frequently used unconventional wire electrical discharge ma (…)
The unconventional wire electric discharge machining technology (WEDM) is widely used in many industries, which is why there is a permanent emphasis on increasing the quality of suchmachined surface. The aim of this study was to carry out a design of experiment (DoE) to reduce the surface qualit yparameter Pq. During the 33-round experiment, the input factors – machine setting parameters, such as gap vo (…)
The present article focuses on the use of neural networks to predict the behaviour of certain diagnostic parameters of spindles of machine tools. An online vibro-diagnostics is used, and from many specific measured parameters, the effective value of some variables in the time series. The results are used in the maintenance based on the technical condition, in particular, in preventive and proactive main (…)
This paper discusses changes in the field of maintenance brought by the Fourth Industrial Revolution - Industry 4.0. Main pillars of the Industry 4.0 are as follows: digitization, interconnection, linking and visualization of all corporate parts, starting from production, through maintenance, and ending by logistics. Maintenance is one of the areas affected most by these changes. It is not enough to m (…)
The present article describes how to use multiparametric diagnostics in maintenance. First, the maintenance is defined and its history is briefly analysed. Subsequently, the maintenance is divided according to current considerations. It is stated that the proactive maintenance represents the state-of-the-art approach to maintenance management. The use of multiparametric diagnostics, such as vibration an (…)
The publication describes an on-the-fly tracking experiment using a self tracking interferometer on a small three-axis machining center. On-the-fly based on continuous measurement, you can get much more measured points while reducing the time required for machine tool calibration than using Trigger or time measurements. The present publication compares the time required for calibration of the machine, a (…)
All of the technical devices that are powered by the frequency converter, apart from their great advantages, also bring considerable pitfalls and risks. When designing a machinery, it is necessary to consider the negative effects of characteristics of the frequency converter on the rotating parts, especially on the bearings of motors, gearboxes, gears, seals, etc. These devices and their parts are usual (…)
This paper describes utilization of a multilateration principle in the multi axis machine error modeling. Multilateration plays an important role in the identification of the exact position of the point in a machine tool workspace. The measured data were obtained using laser tracer in spherical coordinates. The multilateration attempts to improve the data accuracy using only a radial component. Two appr (…)
All photometer-based direct-reading aerosol monitors use the principle of the light scattering to determine airborne particle concentration. Most photometers are calibrated in the factory using a „standard test dust” and are adjusted to agree with respirable dust concentration measurements made using reference gravimetric methods. In practice, it is highly unlikely that the „standard” test dust will exh (…)
The aim of the present article is to provide information on the results of the safety culture assessment carried out in three engineering companies in the Czech Republic in 2017. Determining the level of safety culture helps to reveal the weaknesses in the work process from the point of view of safety in a particular company and, of course, it also allows to propose the necessary measures for improvemen (…)
Low roughness of free-form surfaces represents a challenge in production of forming tools. In the industry, the free-form surface is grinded and polished manually. The technology of hammer peening has the capability to replace the time consuming handcraft by automated machining with high productivity and other positive effects, like increased hardness and compressive residual stress in the surface layer (…)
Mulchers with vertical axis of rotation are highly energy demanding machines and it is expedient to increase their effectiveness. The paper deals with evaluation of the effect of the shape of mulcher’s workspace cover on energy demands and pressure conditions of the workspace of mulcher with vertical axis of rotation. The pressure conditions inside the workspace are connected with the airflow which is v (…)
The topic of the impact of electromagnetic fields on human body is nowadays very actual. One of the physical factors of the work environment is the electromagnetic fields emitted by the electric devices. The effect of electromagnetic fields on human body is various and depends mainly on frequency and intensity. Electromagnetic fields create a wide range of resources with which the workers can meet in th (…)
The paper addresses identification and analysis of individual costs of a life-cycle of engines for railways that meet required emission limits according to STAGE III.B.A cost analysis ofa life-cycle is an effective tool, which allows for observation of various options of technical solutions. The result of an LCC analysis is the basis on which a decision is made about selecting a technical solution of po (…)
The main purpose of this article is to present a new way of straightening hardened shafts. The straightening of regular shafts is usually not difficult, but the situation is very different in case of hardened shafts. The regular shafts are usually straightened by bending of the shaft in the opposite direction than the original deformation. Sadly, this approach cannot be applied on hardened shafts, becau (…)
Increasing demands for manufacturing quality and new standards in surface metrology foreshadow a widespread adoption of 3D surface topography measurement in manufacturing quality control. This raises the question of instrument selection. Coherence scanning interferometry and laser scanning confocal microscopy are some of the most common technologies in optical measurement of surface topography. These me (…)
A dynamic behavior of machine tools always depends on dynamic properties of machine tool individual parts; for example, a spindle unit, frame, ball screw, linear guide, etc. The present paper deals with an analysis of dynamic properties of linear guide RA55AN. The guide was fixed to a special testing stand which enabled us to change and measure radial force loads of the linear guide via a thread mechan (…)
The present paper deals with predictive modelling of thermal deviation of the machine tool due to thermal deformations. Thermal deformation of the machine tool structure is one of the basic problems that need to be addressed when increasing the accuracy of machine tools. For each particular machine tool, it is necessary to measure its behaviour, evaluate it, and, based on the acquired knowledge, create (…)
There are differences in the dynamic behaviour of a machine tool between standstill and process because of preloads, process damping and gyroscopic moments. The standard method to characterize the dynamic behaviour, the experimental modal analysis (EMA), is performed only in the standstill and neglects these effects. In contrast, operational modal analysis (OMA) makes possible a characterisation of the (…)
This article focuses on parameters that influence production of parts by different 3D-printing technologies (FDM, Polyjet Matrix, SLA and SLS). This article acquaints its readers with data and results of research dealing with influence of production process parameter settings on the magnitude of internal material tension of the printed part, or its influence on dimension and shape precision of products (…)
This article is focused on the analysis of tool wear in milling of Inconel 718. Inconel 718 is tough and highly temperature resistive material, which is used due to its excellent properties especially in aggressive corrosive environment. Machining of this alloy is still complicated. The feasibility of three inserts tested for milling of Inconel 718 has been shown in this work. Different cutting speeds a (…)
The influence of high doses of beta radiation on the changes in the structure and selected properties (mechanical and thermal) polymers were proved. Using high doses of beta radiation for polybutylene terephthalate (PBT) and its influence on the changes of mechanical properties of ultra nanohardness has not been studied in detail so far. The specimens of polybutylene terephthalate (PBT) were made by in (…)
DURAMID with 45 % of glass fibre (PA 9T) have been successfully modified using beta rays. PA 9T samples were prepared by injection moulding technology and then were irradiated from 33 to 198 kGy in electron accelerator RHODOTRON. The thermal properties (e.g. DSC and TGA) of modified PA 9T samples by beta rays were measured. The tested samples showed significant changes of thermal properties after irradi (…)
Currently, FDM (Fused Deposition Modelling) is one of the most widely used methods in field of functional prototypes of components creation in various industries. When using RepRap type of printing in some cases occurs to reduced quality of surface area of component that is located on a support, or complications when removing the supporting material. For low surface quality of components produced by usi (…)
Natural zeolite has found important uses in environmental protection and water treatment.In term of chemical, the zeolites belongs to hydrate aluminosilicates and against the their structure they have unique physical-chemical properties. This atribute affords the zeolites utilisation at water cleaning from metal ions. The most offen method of removing metals from solutions is precipitation, which is par (…)
Pneumatic muscle actuators have the highest power/weight ratio of any actuator and therefore it has a broad application prospect in soft robotics. This paper presents a two degree of freedom (2-DOF) pneumatic muscle actuator that consists of four pneumatic artificial muscles (PAMs) and two rotation joins. However, this pneumatic muscle actuator has highly nonlinear and hysteretic properties (among muscl (…)
The article describes the process of optimizing the design of functional parts of radial fans. The main goal was to improve their performance characteristics. The proposed methodology was experimental measurements and the testing station had been built. After processing the results of the experiment the best fan construction option was chosen with optimum performance characteristics.
Vibrations are one of the important monitored parameters, which allow acquiring primary information about the operating condition of the device. It is necessary to bear in mind that vibrations of rotating machines are closely linked to the dynamic stress of the parts like bearings or transmissions. The paper is dealing with the issue of monitoring and diagnosing the size of the two based parameters of v (…)
The aim of the presented paper is to point out the possibilities of determination of new types of belts of the belt gear in case of a newly developed device. The developing and structural-design stage was followed by production and installation of the device. An electric motor serves as a device drive and belt gear input. The other electric motor represents a system load factor. The frequency converters (…)
The degradation behavior of magnesium-based alloys is obviously important for medical applications of biomaterials. Magnesium alloys were investigated as implant materials. This article critically summarizes the in vivo knowledge and experience that has been reported on the use of magnesium and its alloys to advance the field of biodegradable metals. The efficiency of the development approach is discus (…)
The paper is focused on the analyses of the mechanical and physical properties of the hybrid composite systems based on the polypropylene matrix with implemented reinforcing cellulose fibres. The polymer phase of this conventional composites is furthermore modified by physical blowing agents, which are utilized for the formation of light microcellular structures. Interactions of all the components of th (…)
In the area of elastic deformation there is linear dependence between the applied stress and final deformation, which is described by the Hooke´s law. Thus stress and strain are proportional to each other and constant of proportionality is termed as modulus of elasticity (even. Young´s modulus). So this material constant characterizes the elastic deformation behavior of the given material and its magnit (…)
The polypropylene samples for testing were injection moulded and subsequently irradiated by beta radiation at the dose of 15 and 33 kGy with the kind help of BGS Germany. Temperature stability, tensile test, bending test and Charpy-impact test were applied. The influence of beta irradiation low doses on thermal and mechanical properties was subsequently compared. Just dose of irradiation 15 kGy improves (…)
The paper is focused on evaluation of operational safety of chosen electrical set elements in specific conditions of agricultural biogas plants with using of infrared thermography method. The goal of the paper is thermography monitoring of the surface temperature of electrical set elements with detection of high warmed parts. Next goal is evaluation measured temperatures with criteria and requirements o (…)
The objective of gating system design and construction process using high pressure die casting is manufacturing of castings with good mechanical and quality properties. The design must take into account various parameters, ranging from the alloy properties through technical parameters of the casting cycle to the construction of the machine and the mould dimensions. If the design of gating system is mean (…)
The presented paper deals with a design and generation of a program for calculation of stiffness and shear stress of forcing springs. The given calculation program was generated in the program of Microsoft Office through the Excel application by means of defined sequences of the individual orders. The calculation program serves for calculation of stiffness of cylindrical and conic helical forcing spring (…)
The aim of the paper is a structural design of a cutting device with option of length adjustment of cutting material. The introductory part of the paper is devoted to an analysis of available devices standardly employed in the process of wooden substance cutting. The core of the paper contains structural design and calculation of the individual parts, disposition solution of the device and a complete vi (…)
The paper focuses especially on comparison of available programs for design and check of the mechanical components. The main aim of the paper is to analyse in the introductory part the individual programs from the perspective of content and functionality and consequently to compare the results experimentally in selected cases. The paper evaluates simplicity or complexity of work with the individual soft (…)
In manufacturing technology, we often encounter the demand for increasing surface hardness of the machinery components. Although there are new varied coating and surface hardening technologies, those are processes implying increasing costs, economic burden and time required for the manufacturing process including increase in production capacities, increased need for machinery and equipment, or possible (…)
This paper briefly describes some features of control of the hydrostatic recovery module developed within the framework of a research project. This project was focused on research and development of a new product - a hydrostatic system for energy recovery through breaking and start-up of commercial vehicles using control for energy transfer and optimization based on mathematical modeling of the system a (…)
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