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Open access

Michal Frivaldsky, Michal Pridala and Peter Drgona

References [1] Varde P.V., Physics-of-Failure Based Approach for Predicting Life and Reliability of Electronics Components, Barc Newsletter, vol. 313 (2010). [2] Gasperi M.L., A Method for Predicting the Expected Life of Bus Capacitors, IEEE Industry Application Society, Annual Meeting, Lousiana, New Orleans, USA (1997). [3] Bâzu M., Gălăteanu L., Ilian V.E., Vârşescu D., Lifetime prediction for components with scarce data: The “worst case” approach, IEEE 17th International Symposium for Design and Technology in

Open access

Gregor Izrael, Juraj Bukoveczky and Ladislav Gulan

Utilisation of Modeling, Stress Analysis, Kinematics Optimisation, and Hypothetical Estimation of Lifetime in the Design Process of Mobile Working Machines

The contribution deals with several methods used in the construction process such as model creation, verification of technical parameters of the machine, and life estimation of the selected modules. Determination of life cycle for mobile working machines, and their carrying modules respectively by investigation and subsequent processing of results gained by service measurements. Machine life claimed by a producer is only relative, because life of these machines depends not only on the way of work on that particular machine but also the state of material which is manipulated by the machine and in great extent the operator, their observance of security regulations, and prescribed working conditions.

Open access

Ana Diana Ancas, M. Profire, I. L. Cirstolovean, M. Hornet and G. Cojocaru

Abstract

The lifetime of glass reinforced plastic pipes is 50 years. Extensive use of this type of pipe in its various applications, led to investigate their behavior in land that anthropogenic or natural causes, shows the different values of pH to neutral. The paper presents experimental results conducted on three samples of a PN SN10000 DN150 PN10 pipe buried in three different types of terrain: neutral, acidic, basic. They were subjected to axial load, measuring the force applied deformation force function. On the basis of the calculation formulas determined rigidity of the pipeline, the deformation speed of 50 mm / min. This concludes the type of land affects the rigidity of the pipe so its length of life decreases to that provided by suppliers in order to be taken compensatory measures in this regard such as choosing a higher class of pressure and stiffness pipeline than those arising discounted. This will allow for long-term value (50 years) in the mechanical characteristics sufficient for safe operation.

Open access

Miroslava Ťavodová, Daniela Kalincová, Martin Kotus and Ľubomír Pavlík

/0826/15, scientific peer-reviewed collection, pp. 80-89. ISBN 978-80-228-2920-5. MÜLLER, M. - HRABĚ, P. 2013. Overlay materials used for increasing lifetime of machine parts working under conditions of intensive abrasion. In Research in Agricultural Engineering, vol. 59, no. 1, pp. 16-22. STN 01 5084. 1974. Determination of metal material resistance against wear by abrasive cloth. SÚTN Bratislava. STN 41 4220. 1976 Manganese-chromium steel 14 220. SÚTN Bratislava. STN EN ISO 148-1. 2017 Metallic materials - Charpy

Open access

Niusha Safarpour and Ilkka Sillanpää

References [1] Kothandaraman P., Wilson D.T., The future of competition: value-creating networks , Industrial Marketing Management, 30, 379–389, 2011. [2] Chesbrough H., Rosenbloom R.S., The role of the business model in capturing value from innovation: evidence from Xerox corporation’s technology spin-off companies , Industrial and Corporate Change, 11, 3, 529–555, 2002. [3] Drucker P.F, Innovation and Entrepreneurship , Butterworth Heinemann, 2007. [4] Jain D., Singh S.S., Customer lifetime value research in marketing: a review and

Open access

Krystyna Kazimierowicz-Frankowska

Abstract

This paper focuses on a better understanding of the process of reflective cracking propagation through the pavement structure. A series of finite element numerical simulations were conducted to investigate the initial stress and strain states in typical semi-rigid pavements with and without reflective cracks under traffic loading. It was assumed that reflective-cracks propagate from the base layer to the pavement surface. The influence of selected parameters, such as the load position, overlay thickness, and subgrade quality on stress and strain concentrations was investigated. The behaviour of the pavement structure under repeated traffic loading was analyzed in terms of ground compaction. The original theoretical model proposed by Prof. Andrzej Sawicki was used to predict the deformation of a pavement subgrade subjected to traffic loading. The damaging effect of cracks appearing in the pavement structure was investigated. It was found that even a single crack in the pavement structure may significantly reduce the pavement lifetime.

Open access

Michal Šajgalík, Andrej Czán, Juraj Martinček, Daniel Varga, Pavel Hemžský and David Pitela

Abstract

Machined surface is one of the most used indicators of workpiece quality. But machined surface is influenced by several factors such as cutting parameters, cutting material, shape of cutting tool or cutting insert, micro-structure of machined material and other known as technological parameters. By improving of these parameters, we can improve machined surface. In the machining, there is important to identify the characteristics of main product of these processes – workpiece, but also the byproduct - the chip. Size and shape of chip has impact on lifetime of cutting tools and its inappropriate form can influence the machine functionality and lifetime, too. This article deals with elimination of long chip created when machining of shaft in automotive industry and with impact of shape of chip-breaker on shape of chip in various cutting conditions based on production requirements.

Open access

Constance Moretti, Xuyuan Tao, Vladan Koncar and Ludovic Koehl

Abstract

Using their ability to change their color according to an external stimulation, chromic materials can be used to form a color-changing textile. Electrochromism, more particularly, is a colour change phenomenon caused by the application of an electrical potential. A flexible textile electrochromic device composed of four layers is presented. In order to improve the lifetime of this structure, the electrical performances of the electrolyte layer are studied. A method to measure and calculate the resistance variations of the electrolyte applied on a textile cotton substrate is given. Relations between the electrical performances of the electrolyte and the electrochromic effect of the device are also highlighted.

Open access

Paweł Lindstedt and Rafał Grądzki

A Synthetic Method for Examination of Potential Reliability and Safety Level Demonstrated by Technical Facilities During Their Lifetime

The paper presents fundamentals for an innovative method that takes advantage of diagnostic information defined with participation of an expert. (presented as a score of points). Defined number of points is assigned to each signal change, depending on the signal value and the moment when the change occurs, whilst the number of points is preliminary defined by an expert. The proposed innovative method consists in the use of signals represented by the scores to determine combined status equations [3, 5] for parameters of the adjustment control state and technical state (equations 3 and 4) and then parameters of reliability and safety (equations 5 and 6). Such an approach enables continuous monitoring of the reliability and safety states of facilities during their lifetime. The presented approach may prove to be extremely useful as it unambiguously presents wear and tear of the facilities and enables to predict when the facilities should be repaired (overhauled).

Open access

Henryk Tomaszek, Ryszard Kaleta and Mariusz Zieja

Abstract

A model to monitor the risk of a failure/damage (undesirable event) to a means of transport has been outlined in the paper, with findings presented in [2] applied. Destructive processes such as the wear-and-tear, fatigue, and ageing, which arise in the course of the system’s (here: the means of transport) service are most fundamental factors that make health/maintenance status thereof deteriorate. A relationship that describes the probability of an undesirable event (failure) against the system’s service life has been formulated. The rate at which undesirable events may occur, i.e. the failure rate, has also been defined. What results from derived relationships is the statement that failure rates are functions of time the system remains in service. With the permissible risk level assumed, there is a chance to determine the permissible time of failsafe operation.