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Shaping of the surface roughness in traverse grinding is much more complex compared to plunge grinding. What significantly influences the roughness of the machined surfaces in traverse grinding is the dressing of the grinding wheel, grinding parameters, and the form of the grinding wheel wear in this proc-ess. The occurrence of wear steps on the active grinding wheel surface (AGWS) causes that the...
In the process design stage of deep drawn components, an innovative concept means introduction of new features in the area of blankholders. When deep drawing the complex sheet metal parts, one must be able to control the flow of the non-uniformities of material between the punch and die in order to elimi-nate the undesired occurrence of wrinkling and tearing of a drawn component. This can be made...
The aim of the paper was to analyse the estimation errors of total duration of tasks performed in se-quence and simultaneously, on the basis of estimates of duration of individual tasks at various probability distribution of these durations. The estimates are directly connected with buffer sizes in Critical Chain Project Management (CCPM). An analysis of the total duration of tasks performed in sequence...
The geometry of the dresser is a quantity influencing the real conditions of the grinding wheel dress-ing. Monitoring of the dresser wear is necessary because the active grinding wheel surface depends on it, together with the resulting workpiece surface roughness. The structure of the monitoring system of the single-point diamond dresser wear, the methods of carrying out measurements and their examples...
This study presents the theoretical bases and the concepts of modelling the interaction between em-bankment and mining subsoil and predicting its deformations. These bases and concepts mainly focus on examining the mining tension strains and on the safe operation of road constructions. Some solutions (by employing MES) in the flat and spatial state of strain, including a change in location of the...
The paper presents the mutation of standard local interpolation of a sequence of points by the Bezier segments. This method is applied in photoelastic experiment, but can be used in any approximation where the data are distributed sparsely. Finally the results of approximation of photoelastic experiment to be as-sessed in FEM calculations have been presented.
The results of macroscopic and microscopic investigation, hardness tests and abrasive wear out tests of different pad welded layers made with thirty nine kinds of electrodes are presented. Defectiveness of the layers was connected with a foreseen character of their wear out. The possibility of simplifying the chemical composition of electrodes without deterioration of application properties of pad...
The paper deals with the planning of assembly sequences. An evolutionary algorithm for the planning of assembly sequence has been developed. Its use is illustrated by an example and the results obtained are discussed. The application of the algorithm to production process control can bring substantial benefits, which involves quick preparation of the system for performing manufacturing tasks and for...
This paper analyses the issue of optimization of composite materials – Self-Compacting Concrete with cement–fly ash matrix. The characteristic and experimental testing of Self-Compacting Concrete are presented. The issue of optimization is outlined, the objective function is formulated and preferred solu-tion is calculated, i.e. the point from the set of compromises, the one closest to ideal point,...
The features and the effects of hybrid machining have been described in this paper. The grinding process has been assisted by electric discharges (AEDG – Abrasive Electrodischarge Grinding). The ex-periments have been performed with the electrodischarge machine tool from the Charmilles Technologies (model FORM - 2LC ZNC), equipped with extra grinding wheel made of metal bond CBN grains and functioning...
Based on viscoelastic analogy and Laplace’s transformation, a constitutive equation for creeping buckling of standard viscoelastic compressed bar model is derived taking into consideration non-dilata-tional strains. The equation derived is solved and critical bearing capacities as well as creep coefficients of compressed bars of a standard model are determined. The table illustrates time displacements...
The high-pressure hybrid jet treatment is a new technology that has grown recently in popularity. Such technology is based on a high-pressure abrasive-water jet with addition of dry-ice pellets. Theoreti-cal basis of treatment taking account of the kinetics and thermodynamics of solid particles and their dis-tributions and pressure in hybrid jet is discussed. Based on theoretical results we undertook...
Abrasive instruments in the form of sheets and rolls are often used in industrial processes. Hence, the quality of the related work is entirely associated with the roughness of their surfaces. In order to charac-terize the topography of the latter, the optical techniques are employed. In the present paper, the methods based on light scattering and self-shadowing phenomena are presented. Unlike other...
The aim of the article is to present the author’s proposals of calculating concrete ultimate direct shear strength fctb and fatigue direct shear strength fctbf. The effect of scale, important in investigating concrete strength, has been taken into account. The conclusions are valid for concrete class B 30–B 50, hole diameter ř = 20–40 mm and strip thickness t = 12–20 mm. The doubts about the diameter...
In order to reduce the time of designing technological process and selection of optimal variant of process with regard to qualitative and economic aspects, expert systems are often used. Computer tech-niques improve and speed up the selection of assembly devices and also allow us to calculate the costs of their application in assembly process of a given product. Knowledge and experience of designer...
The study presents the results of examining the distribution of strains and stresses in the normal cross-sections of bended gypsum beams, dry prepared, made of building gypsum pastes at water-to-gypsum (W/G) ratios equal to 0.5, 0.6, 0.8, 1.0 and 1.5. The strain was measured by the strain gauge method, whereas deflections of the beams were measured with displacement sensors. Strain distributions were...
Research on bond under cyclic loading is usually performed using specimens of a very short bond length. Results of such a research show very often that bond can be completely destroyed. According to that, most standards demand some extra anchorage length of steel bars. Different results were obtained by the author from experiments on long specimens under eccentric tension. If a concrete member is...
In the paper, the capabilities of the MSC/NASTRAN system in the field of stability analysis of com-posite laminated shells are critically tested. Two selected benchmark examples of laminated cylindrical panels under axial compression are examined. The MSC/NASTRAN results obtained either in buckling analysis or in nonlinear incremental calculations are compared with the solutions available in the litera-ture.
Composite structures consisting of thin reinforced laminas, modelled as orthotropic bodies, are con-sidered. The problem of the optimal shape is examined within the scope of sensitivity and optimization theories, particular consideration being given to shape sensitivity and optimal shape design. The boundary element method (BEM) approach has been formulated and implemented in the computer code, which...
In this paper, the dynamic response of a linear structure to a random train of pulses driven by a Pois-son process is considered. An analytical method is developed to determine spectral density function of the response of the structure. Both stationary and non-stationary vibration problems are considered. To as-sume simple algebraic relations for both cases of response the dynamic influence function...
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