Solid State Phenomena Vols. 147-149

Abstract: The purpose of this work is to segment large size triangulated surfaces and the contours extraction of the 3D object by the use of the object curvature value. The curvatures values allow categorizing the type of the local surface of the 3D object. In present work the curvature was estimated for the free-form surfaces obtained by the 3D range scanner. A free-form surface is the surface such that the surface normal is defined and continuous everywhere, except at sharp corners and edges [2, 5]. Two types of distance measurements functions based on Euclidian distance, bounded box and topology of surface were used for the curvature estimation. Clustering technique has been involved to cluster the values of the curvature for 3D object contour representation. The described technique was applied to the 3D objects with free-form surfaces such as the human foot and cube.

Abstract: In this paper, laser-induced breakdown spectroscopy (LIBS) using micro-droplet NaCl solution and set-up for control of micro-droplets are described. Micro-droplets controlling technique is important for solution quantitative analysis. In this study, micro-droplet ejection system for sampling is designed and presented. This micro-droplet ejection system enable a constant volume of the sample liquid to be obtained and it takes advantage of the liquid physical state; the density of the solution can be controlled accurately. The method presented here generates small droplets (diameter 30 μm) by confining the entire volume of the sample material in the laser beam spot area (minimum beam spot diameter: 53.2 μm) and separating it from its surroundings. Using this liquid micronizing method, improved sensitivities are obtained. The Advantage of LIBS is a useful method for determining the elemental composition of various materials regardless of their physical state (solid, liquid, or gas) and without any preprocessing; it is a type of atomic emission spectroscopy (AES). Despite the advantage of qualitative analysis, quantitative analysis is difficult because of sample and plasma fluctuations. Generating constant volume of micro-size sample and proper sample control technique contribute to LIBS quantitative analysis.

Abstract: The structure of the experimental set-up for electromagnetic ring expansion and its electric properties are presented in the paper. While earlier expanding ring apparatuses were usually equipped with shaped-charge, thyratron or ignitron switches, we propose to use the impulse high-voltage thyritor as a switch to discharge capacitor bank. Furthermore, the preliminary results of the copper ring fragmentation properties are presented for different initial charge of capacitor bank (0,5 ÷ 2 kV). On the basis of our calculated and preliminary experimental data of the ring motion for expansion at 2 kV, we estimated the radial ring velocity, which was close to 250 m/s.

Abstract: Predominantly coaches are preferred for intercity passenger transportation in our country. Vehicles are supposed to meet the passengers’ expectations in terms of safety, comfort and health during journey. Some features such as an internal environment that has an adequate and balanced temperature level is one of the essentials of the features affecting passenger comfort directly. To provide these, various coach manufacturer firms are continuing to make many trials and test studies at design stage. For that purpose, the vehicle-heating and cooling capacities of the intercity coaches were analyzed and examined in the scope of this study, by means of the thermometers and data acquisition systems (DAS). The thermal measurements related the subject were made on the intercity coaches at the Development & Test Center of a intercity coaches producer firm. The measurement results obtained from the experimental studies were examined and in consequence of the assessment of these data, implementation of the optimum resolutions was recommended in terms of passenger health and comfort.

Abstract: In order to compare the strengths of various materials it is necessary to carry out a standard form of test to establish their relative properties. The tensile test, compression test, bending, shearing and torsion tests are used for examining mechanical properties of biological materials. Except for non-destructive methods (optical, electromagnetic, sonic, thermal, infrared), destructive testing is another very important tool for the assessment of biomechanical properties and behavior of biomedical materials. The tensile strength test is one of the most common testing methods, which uses specific testing machines. Many tensile testing machines are equipped to plot a curve which shows the load or stress and the strain or movement that occurs during the test operation. In the testing operation, the load is increased gradually and the specimen will stretch or elongate in proportion to the tensile load. The load cells and extensometers measure the key parameters of force and deformation. The presented paper is a report which describes a specific and unique technical solution and upgrade of FM 1000 machine from the control and output processing point of view. Modern sensoric systems and I/O modules were used and custom software was developed. The fu

Abstract: Adhesively bonded joints are used extensively in various industries. Some imperfections like holes, thermal residual stresses occurring in the bolted, welded, riveted, and soldered joints don't take place in adhesively bonded joints. Hence, the main advantages of bonded joint are lightness, sealing, corrosion resistance, heat and sound isolation, damping, and quickly mounting facility which have been highly proved. This paper introduces an attempt to study the dynamic analysis of adhesively bonded joint for composite structures to investigate mainly the influences of lamina code number, bonded adhesive line configuration and boundary condition on the dynamic behavior of the test specimens containing composite assembly. The numerical based on the use of finite element model (FEM) modified by introducing unified mechanical properties are represented and applied to compute efficiently the Eigen-nature for composite bonded structures. The experimental tests are conducted to investigate such adhesive bonded joints using two different techniques. The first technique includes an ultrasonic technique in which the magnetostractive pulse echo delay-line for material characterization of composite material is used. The second technique is bassed on the use of the frequency response function method (FRF) applying the hammering method. The comparison between the numerical and experimental results proves that the suggested finite element models of the composite structural beams with bonded joints provide an efficient by accurate tool for the dynamic analysis of adhesive bonded joints. The damping capacity is inversely proportional to the stiffness of the bonded joint specimens. The type of the proportionality depends mainly on the bond line configuration type, lamina orientation, and boundary conditions. This in turn enables an accurate evaluation for selecting the proper characteristics of the specimens for controlling the present damping capacity and the proper resistance against deformation during the operating process. The present study provides an efficient non-destructive technique for the prediction of dynamic properties for an adhesive bonded joint for the studied composite structure systems. The coordination of the experimental and numerical techniques makes it possible to find an efficient tool for studying the dynamic performance of adhesively bonded joint for composite structures.

Abstract: This paper presents the method of designing a mechatronic system, as a result of an integration. As an example of the integration automation components, in one coherent measuring system, a measurement path for temperature sensors is proposed. A measuring path can be defined as a scale model, which reproduces thermal states of a temperature sensors system, used in real industrial applications. The system is extended by database application based on Access. Taking advantage of an iFIX special database block the temporary values of temperature are recorded in Access database with permanent period of time. The final analysis is performed in an Excel sheet.

Abstract: The precision line scale calibration in dynamical mode of operation is considered. A new interferometer-controlled comparator with moving microscope has been developed and optimised in order to reduce both the measurement uncertainty and calibration process duration. Modal analysis performed and measurements conducted of the spatial vibrations of comparator structure revealed that dynamically-induced errors can noticeably contribute to the measurement uncertainty budget. They can be prominently reduced, in particular, by proper improvement and optimisation of the carriage structure and elimination of the dry friction in the carriage drive.

Abstract: For perfect surface roughness description is not enough to know characteristics of surface profile. It is necessary to use topography methods, so called microtopography. Thereby, surface roughness in microtopographycal understanding must be described with three coordinates, whose in Cartesian coordinates system compose point under consideration height h, abscissa and ordinate, determines point position in the plane. Most efficient methods in irregular surface roughness research are random function theory methods. Therefore, microtopography, analogically to profile, may consider as random function, but two dimensional function, i.e. two variable x and y random field h(x,y). From analogy with random process, random field can be normal – ordinates are distributed by normal (Gaussian) distribution. Moreover, random field can be homogeneous and heterogeneous. Random field is deemed homogeneous if its mean value is discretionary and correlation function depends only from distance between surface points. Important characteristic of random field is correlation function, whose depends of two variables t1 and t2 – orthogonal Cartesian coordinates of vector t. Random field is homogeneous and isotropic when its characteristics are equivalent in any direction. There are three types of surface anisotropy: • General event of surface anisotropy. Characteristics of this event roughness parameters are depend of surface split direction. • Surface roughness with direct anisotropy. Those surfaces are with typical traces of tool and they proper two mutually perpendicular surface roughness directions. • Extended anisotropy area – special event of anisotropy roughness. Of analytical opinion, gainfully anisotropy roughness see as extended occasional isotropy area. This let easy cross from anisotropy surface to isotropy and contrariwise, thereby embrace amount class of surface roughness. Let’s formulate microtopography model of rough surface [1]. Surface roughness is described with homogeneous normal random field h(x,y) that has uninterrupted correlation function and uninterrupted deriviates. We may consider that E{h(x,y)}=0. The mean random field value is plane called mean plane. For describing random field we must know mathematical expectation and field correlation function, what in fact reduces on determining dispersion and rationed correlation function r(t1, t2). Homogeneous random field dispersion D{h} doesn’t depends of direction and can be founded in any surface split. Given model of rough surface let inspect surfaces produced by abrasive instruments and friction surfaces after wear-in period.

Abstract: Dependence of a comparator reading dynamic error on vibro activity of a carriage is analyzed in the paper. There is shown how change reading errors at action only carriage drive vibrations and at artificially provoked carriage vibrations at different frequencies. Results achieved enable to evaluate the influence of vibration components on reading errors.