Applied Mechanics and Materials Vol. 657

Abstract: The strongest vibration in the Saarland has caused some significant damage patterns mining induced as a consequence vibrations. This paper discusses about the technical options to eliminate resulting incurred damage to the buildings.

Abstract: The measurement of symmetry and nominal position deviation from theoretical point of view is not a problem, the main issues appears when these theoretical aspects aren’t applicable in industrial practice. The problem addressed in this paper is to identify the possibility to develop a method for the intermediary control like a necessity to industrial practice but for a small series production.A theoretical analysis was developed in order to identify the measuring possibility of symmetry and nominal position deviation for a specific keyway. Using chart ideas and making a case study, we thought to find a practical solution of the intermediary control for specific keyways gears, in small series production case. The research tries to highlight some common and distinct aspects specific for those measuring methods and to solve the issue of intermediary control for a small series production in case of gears internal keyways.

Abstract: The present paper presents the implementation of a numerical model for a natural storage transformed into a deposit which takes into consideration the geometry of the storage, the properties of the rocks and in which the movements of the gases can be described. The model is two-dimensional nonstationary and allows the dynamic simulation of the processes of injection and extraction. The location of the wells and their flows can be thus studied and optimized to maximize the amount of the stored gases. The presented model allows the quick finding of solutions for a whole cycle of storage in a short time so that it could be used successfully in the operation process.

Abstract: Weighing in motion systems, regardless the type of sensor that a system utilizes is working in difficult conditions: dust, slag, layer of ice or snow, high humidity, varying temperatures during a day, or a year [. All these conditions influence the accuracy measures of the work done and require the correction factors application.In this paper it presents the analysis of the temperature influence on a new type of weighing in motion sensor, namely hydraulic sensor. Is presented the simulation scheme designed to simulate the experimental model used in the laboratory and the results obtained through simulation, on the temperature influence on the experimental model tested.

Abstract: Noncircular gears are continuously challenging the specialists from the gear industry, due to their industrial performance and new research abilities induced by the advances in virtual modeling and processing technologies. The authors propose the Gielis’ supershape as the chosen geometry for the driving pitch curve in order to generalize the noncircular gears design. Specific algorithms are developed in accordance to the supershape geometry complexity and restrictions resulting from a “technical” selection of a proper pitch curve from the wide family of supershapes. Original steps and codes enrich the traditional noncircular design procedure, divided into: i) studies on the influence of the supershape defining parameters on its scaled geometry, according to specific gear data such as number of teeth and gear modulus; ii) generation of the driven gear pitch curve, based on the kinematics and geometric conditions of pure rolling between mating centrodes. New codes and an iterative procedure are applied to solve the step key problem, respective the center distance determination, respectively; iii) noncircular gear virtual generation, developed using both solid modeling, for the gear cutting process simulation, and analytical procedure.

Abstract: Important investmentsare made lately in the area of district heating, as a technology capable ofhelping countries to reach sustainability goals. In Romania, European fundswere spent for transition from the 2^nd to the 3^rdgeneration of district heating systems. The lack of appropriate monitoringsystems in old district heating systems makes optimisation nowadays very difficult,especially because nominal values used in the first design stage areoverestimated. Realistic nominal heat loads are necessary to make goodestimations of hydraulic parameters to be used for redesign. This studyproposes a method that uses the heat load duration curve theory to identify theappropriate nominal heat loads to be used for redesign. Comparison betweenresults obtained by applying the nominal heat loads of each consumer, as theywere established in the first design stage, and the ones identified by theproposed method are analyzed in a case study. The results show that errors arein the +/- 3% band, between the metered heat consumption rates and the proposedrates. The new method can be used for the sizing of pumps and district heatingnetworks after retrofit, in order to get better adjustments of the circulationpumps and increase of the energy efficiency.

Abstract: The paper presents the results of an experimental study performed on specific measuring devices micrometers, study aimed at determining the calibration life of these measuring devices as a function of the metrological reliability, due to the internal parameter deviation. The experimental study conducted is aimed at determining the calibration life of external micrometers for 0 - 25 mm. The experimental data is obtained in the laboratory conditions and it is represented by the measuring errors, obtained for the same nominal size, experimental data being grouped in samples produced at a certain interval of time, by measuring the same dimension with a set of micrometers.The research performed on the considered set of micrometers can lead to the conclusion that the appropriate moment for performing the calibration for a specific set of measuring devices can be estimated by determining the calibration life based on parameter deviation functions, these being obtained by means of regression analysis. The algorithm for estimation of the calibration life of the measuring devices as a function of the metrological reliability can be used for determining the calibration life of the analysed measuring devices, such as to compare the estimated calibration life with the requirements set in the appropriate standards. In the case of the set of micrometers analysed, the pre-set calibration life proved to be earlier than necessary and the estimation of the calibration life by means of parameter deviation would reduce the total costs of the appropriate operation.

Abstract: This paper work presents some aspects of modeling the behavior an object in an upward airflow with possible applications in pneumatic elevators. In the premises known from the literature, was formulated the physical model of corp behavior at air flow varying. In the first stage of the work, was completed in Solid Works the physical model and the functioning simulation in Flow Simulations. The imput data was provided in solving the mathematical model in Matcad 13. To achieve the control system was chose an open sources software solution with SCADA interface made in Pro wiew.

Abstract: Besides the actual average pressure, the actual specific fuel consumption and the actual performance, the actual torque is one of the characteristic indicators considered when designing a spark-ignition engine. In order to determine the effective power, special and quite expensive benches are required. This paper intends to determine certain computational relations for the determination of the actual torque both for a standard engine and for a ceramic-coated engine. In order to obtain the experimental results, we used the spark-ignition engine 810-99, and the actual torque was determined on a specialized bench. All measurements were performed at 28°C air temperature, and 740mmHg atmospheric pressure, the temperature of the cooling liquid being 82÷91°C and the oil temperature 92÷116°C. For the engine with ceramic crown’s piston, was maintained the same compression ratio, and the atmospheric pressure and temperature conditions were close to those of the standard engine. Both for the standard engine and for the ceramic engine all measurements were performed under full load. After computer processing the experimental data, empirical formulas were determined for the computation of the effective power both for the ceramic engine and for the standard engine.

Abstract: This paper presents an approach to various forms of security and different access levels required in an information system by analyzing mathematical models that can be applied to this field. By describing their structural characteristics and how they find implementation in the study of information security, this paper underlines the necessity, means and effectiveness of information security modeling. The conclusions of this paper highlight the importance of a well-defined security risk management and how achieving this goal provides an opening for future research.