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  • Author: Marek Krynke x
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Abstract

The strategy should be designed in such a way as the risk management can operate not only as a system for avoiding losses, but also risk management should allow recognizing and making use of occasions and create new opportunities for the organization. Risk management includes both an evaluation (analytical and evaluation) undertaking as well as planning and control activities aimed at minimizing (reducing) risk or maintaining it at an acceptable level. Security management can in particular be reduced to the issue of risk management, because risk is a quantitative expression of the functioning of systems in an environment where there are active sources of threats to system security. The article presents the problem of personnel allocation in hazardous conditions, emphasizing the possibilities of undertaking optimization actions in the safety management process. A mathematical model was formulated for this issue. An algorithm solving the problem of personnel allocation is presented. The proposed analysis is the starting point for determining the risk when using multi-station work.

Abstract

The allocation of production tasks to specific production resources is an important part of preparing the manufacturing process. The amount of profit and costs incurred depends on this division. The efficiency of production resources depends not only on the technologies used, but also on the tasks that will be carried out on them. Therefore, the management of machine efficiency includes both an evaluation (analytical and assessment undertaking, e.g. OEE) and planning activities aimed at maximizing the efficiency of machines by appropriately assigning production tasks to them.

The article presents the problem of the allocation of production of various products to various production resources, including the efficiency of the use of machines and devices, emphasizing the possibilities of undertaking optimization actions in the cost management process. A mathematical model was formulated for this issue. An algorithm solving the problem of allocation of production tasks is presented. The solution was obtained using the Octave computing environment.

Abstract

The article analyzes of the load capacity of the rotation mechanism of the boom arm sub-assembly for a self-propelled crane. The uneven flexibility of systems supporting structures of the machine was taken into account in the identification of the load. The consideration are illustrated by the example slewing bearing from self-propelled crane. FEM method was used for calculations. The basic problems of construction of numerical model were discussed. Sample calculations of bearing carrying capacity has been done taking into account flexibility of bearings supporting structures, which also allowed to define the internal load distribution in the bearing. On example of the supporting structure of the mobile crane DST 5050 the internal load distribution in the crane bearing at different positions of the crane machine body were defined. During the rotation of the crane body priority angels were indicated. It has been shown that the deformations of the supporting frames are so large that they significantly change the distribution of forces transmitted by the individual bearing rollers.

Abstract

The paper is focused on determination of the accuracy and reliability of static and dynamic (portable) hardness testers. The paper deals with the measurement of hardness of calibration hardness plates by 4 different methods (Brinell, Vickers, Rockwell and Leeb) with using 5 different hardness testers (3 static and 2 portable). The hardness values measured by the different hardness testers were compared to the reference hardness listed in the calibration hardness plates and consequently, the accuracy of these measurements was evaluated. The aim of the work has been to determine the accuracy and reliability of portable hardness testers in comparison with static hardness testers.

Abstract

The proper organization of work is to set the workflow to the slightest effort of man and machine operation to obtain maximum results. The article presents the problem of the allocation of personnel that occurs in a real company. The mathematical model for this issue was formulated. An algorithm solving the problem of personnel allocation is presented. The proposed analysis is a starting point for determining the production capacity and load of each workstation, which is particularly important when using multi-station work and balancing the production line.

Abstract

In the article some forms of damage to raceway of slewing bearings for single-row ball bearing slewing ring with four-point contact and their causes were shown. Changes of the contact angle and its influence on the geometry for contact zone of the rolling elements raceway were analyzed. An identification of changes for contact angle of individual balls for different parameters of the contact was received. It was showed that contact angles of some rolling elements were increasing. It can cause damage to the raceway by spalling or rolling out of edge of the bearing ring. Ways of avoiding too early damage to the raceway at the stage of the design and the selection of coronary bearings were suggested.

Abstract

In recent years, the research of nodular cast iron has been focused on increasing fatigue resistence. In the paper, two types of alloyed nodular cast irons have been investigated – SiMo-nodular cast iron alloyed by 4% of silicon and 1% of molybdenum and SiCu-nodular cast iron alloyed by 4% of silicon and 1.5% of copper. SiMo-nodular cast iron is suitable for high-temperature applications, for example the exhaust manifolds of the combustion engines. SiCu-nodular cast iron is used in various components of tribotechnical units. These components are often loaded by fatigue. The mechanical and fatigue behaviour of both nodular cast iron types has been studied by means of tensile test, impact bending test, hardness test and fatigue tests. Fatigue tests were realised at low frequency cyclic push-pull loading up to 10 million cycles. The relationship between the amplitude of stress and number of cycles to failure was investigated and the fatigue strength was determined. Mechanical and fatigue properties of both nodular cast iron types are correlated with the microstructure of specimens.

Abstract

In this paper TPM and PAMCO coefficients were shortly characterised. On the basis of TPM coefficients its effectiveness was estimated. Thanks to using time and PAMCO coefficients, the utilization of working time machines was researched. Moreover, there a correlation between TPM coefficient and the quality level was examined. A histogram was drawn up in order to illustrate the distribution. The obtained results allowed to evaluate the effectiveness of the machine. The period of research embraced fifty-two weeks (1 year) and the object of the analysis is the injection moulding machine.