Applied Mechanics and Materials Vol. 474

Abstract: The article focuses on the field of PMMA laser micromachining at change of the technological parameters. The aim was to evaluate machined surface roughness at different setting of DPI definition (number of dots paths on square inch). Commercial CO₂ laser Mercury L-30 by firm LaserPro, USA was used for experimental machining. Ray of laser could be focused on mark diameter d=185 mm.

Abstract: The article deals with application of fractal geometry on a surface of polymeric material (artificial leather) obtained by laser micromachining. There was done an experimental manufacturing of the chosen entities at the change of a technological parameters and laser beam mode. The aim was to consider possible changes of the given surfaces resulting from different laser beam mode (pulse vs. continuous).

Abstract: This article is focused on a production of mechanically resistant physical models using Rapid Prototyping technology. There are two tested materials, ABS is the first build material and ABS-like is the second build material with similar properties. The article describes the production of a testing component - element for tensile tests by two RP technologies. The first technology is FDM (Fused Deposition Modeling) and the second PolyJet Matrix. Further the article describes the description and evaluation of the tensile tests.

Abstract: The paper deals with the possibilities of using non-contact 3D measurement systems for the digital capture and subsequent dimensional and shape analysis of multi-part forms. The paper illustrates a practical method of the 3D digitization of two-part moulds using a combination of TRITOP and ATOS optical systems. It introduces dimensional control of the cavity of a mould during its real closure and compares this method to traditional methods of measurement. The analyses carried out show the undeniable benefits of these innovative approaches in practice, because the appropriate use of optical methods often enables the detection of the errors of products and tools which would be impossible to detect using traditional approaches.

Abstract: The aim of the paper is to study the effect of the surface shape and perforation of plastics on sound absorption. Samples with different asperity heights, depths and numbers of holes were prepared by means of CNC milling machine. Experimental measurements of frequency dependencies of the sound absorption coefficient were realized by the transfer function method using Kundt ́s impedance tube at normal incidence of acoustic wave on the investigated materials. The study was performed on two types of polyurethanes. Different factors, that have influence on sound absorption, are evaluated in the conclusion of this work. Both investigated materials are also compared in terms of their ability to absorb sound.

Abstract: The article examines the change of the slip-line fields structure with the help of numerical simulation (FEM) in the case of hard turning by gradually decreasing the tool rake angle. During the examination the influencing effect of the stagnation zone on the chip removal was taken into consideration. The stagnation zone is typical of the cutting done by a negative rake angle and it is generally present in front of the tool tip.

Abstract: In rotational turning the kinematic relations between the tool and the workpiece are different from traditional turning. The cutting edge is more complex (can be typified by helical geometry) and the feed motion is the result of the tool rotation. Therefore, the characteristic parameters of the procedure must be determined by methods different from traditional turning. In this article we determine some characteristic parameters of the cutting run-in phase (which ends if the chip cross-sectional area becomes constant): the axial length, the needed rotation of the tool and the duration.

Abstract: The study summarises the results of the analysis of the diamond burnishing process. The subject of the analysis was whether the diamond burnishing can be done with the use of the type of lubricating material which hardly pollutes the environment. Of course, we used conventional oil for lubrication as well, which served as base data. The effectiveness of the process was examined by analysing the surface roughness when changing the technological parameters such as burnishing speed, feed, and burnishing force. Besides examining the parameters of surface roughness we examined the improvement ratio of surface roughness as well as the function of burnishing technological parameters. The empirical formula for determination of the improvement ratio of surface roughness was determined by the use of factorial experimental design.

Abstract: The CAD/FEM systems enable the analysis and development of any constructional solutions. They are particularly effective for the complex technical means. In this regard, investigations are conducted to develop methodological concept for the design using the virtual environment [1,2,3,4]. This paper presents the solution basing on the proposed structure of the complex technical mean consisting of three components: structural system, drive system and control system. The structural system includes the carrying and functional elements. The drive system refers to the elements responsible for activating the functions of technical means. However, the control system is responsible for the implementation of the selected sequence of actions. Basing on such formulated concept it was presented the project of the powered roof supports with the strait-line mechanism. The work describes the results of the virtual analysis of the elaborated roof support construction. They are considering with the analysis of its functioning and with the fulfilment of the requirements consider with the human factors.

Abstract: Production logistics is an element of the logistics system. This article presents its basic tasks and the scope of support for information technologists. The advance in the development of IT systems gives a new form to production enterprises supporting professional management of all logistics processes. Thanks to modern IT technology, production enterprises have the possibility of transformation, which enables them to carry out a new range of activities. The Author highlights in the paper the revolutionary role of integrated IT systems using the examples of selected systems, whose efficient implementation enables covering the operational needs of production enterprises. Although in the case of logistics, information has always constituted the basis for management, it is now when, thanks to the suitable technology, it has become the basis for competitive logistic strategies. Information, apart from workforce, capital, materials, is one of the basic resources of an enterprise, while IT systems have significantly extended the opportunity to make use of information which serves not only building reports or lists, but also covering operational needs of an enterprise. Thanks to those systems certain pieces of information can be used repeatedly without paying attention to their relevance. Proper implementation and use of integrated IT systems currently constitutes the basis for business management.