Applied Mechanics and Materials Vol. 186

Abstract: The paper presents an analytical calculus for the bending beams on elastic environment. The elastic environment sends in all points a reaction force proportional to the deformation with the same constant of proportionality in all points. The calculus of the state vectors associated at the origin section and at the end section of the beam is made by Transfer-Matrix Method, putting the conditions on the supports (extremities) of the beam. After, we can calculate all state vectors for all sections of the beam.

Abstract: The present research aimed to study the possibility to increasing flame retardancy of polymeric composite materials reinforced by fibers by coating by a flame retardant layer represent antimony tetroxide (Sb4O6) as a coating layer (4mm) thickness to react and prevent spread of flame on surface of composite material consist of epoxy resin reinforced by Kevlar fibers and exposed this coating layer to oxyacetylene flame with different exposure intervals (10,15,20mm) and study the range of resistance of flame retardant material layer to the flames and protected the substrate .The experimental results show that a great increment in thermal resistance and flame retardancy after coating by tetroxide as well as rising flame resistance increased exposure distances to flame . Determination the percentage contribution effects of main factors were time , exposure interval ,and noise variables (error) to the variability of the surface temperature at significant level (α=0.05) .Results show that the percentage of main factors were :time=63.15% , exposure interval=14.81% and noise variables=22.04%.

Abstract: This paper presents the mathematical model of the straight bevel gear flanks with octoid II teething which is measured with a coordinate measuring machine, type DEA Global Performance. The mathematical model is realized by theoretical equations which occur in the face gear. The experimental data, obtained by using the coordinate measuring machine, is analyzed and the compensation of the probe tip is calculated. The differences between the surfaces are determined.

Abstract: Reconditioning materials by thermal spray metalizing is a rapidly growing field. In this paper we conducted a comparative study of three methods of metal deposition: flame spraying, atmospheric plasma spraying, arc spraying. This was done considering two of the properties of layers obtained in metalizing process: surface adhesion strength and porosity. The result of ultrasound examination by immersion shows that adhesion obtained through APS method is better than the others two obtained through AS and FS methods.

Abstract: This paper presents a tools management ways (VB for Excel) for small and medium enterprises. The implementations are simple and accessible. The monitoring tools and insurance a minimum stock (for the manufacturing process without interruption) are the necessary elements to manage. The technological itinerary dictates the type and list of needed tools, to ensure the manufacture process. By using a mobile system for transfers the used tools into warehouse and the necessary tools to CNC manufacturing center, the preparation time for the manufacturing process, can be reduced. This can be monitored and managed by using a barcode scanner and dedicated software.

Abstract: One of the most important factors which influence on the dynamical behavior of the linear motor servo drives for CNC machine tools is position loop gain or Kv factor. From the magnitude of the Kv-factor depends tracking or following error. In multi-axis contouring the following errors along the different axes may cause form deviations of the machined contours. Generally position loop gain Kv should be high for faster system response and higher accuracy, but the maximum gains allowable are limited due to undesirable oscillatory responses at high gains and low damping factor. Usually Kv factor is experimentally tuned on the already assembled machine tool. This paper presents a simple method for analytically calculation of the position loop gain Kv. A combined digital-analog model of the 4-th order of the position loop is presented. In order to ease the calculation, the 4-th order system is simplified with a second order model. With this approach it is very easy to calculate the Kv factor for necessary position loop damping. The difference of the replacement of the 4-th order system with second order system is presented with the simulation program MATLAB. Analytically calculated Kv factor is function of the nominal angular frequency  and damping D of the linear motor servo drive electrical parts (motor and regulator), as well as sampling period T. :The influence of nonlinearities was taken with the correction factor. Our investigations have proven that experimentally tuned Kv factor differs from analytically calculated Kv factor less than 10%, which is completely acceptable

Abstract: The paper presents the structure and performance of the system created by a work team at Department of Production Systems and Robotics at Technical University of Kosice. System MSEVR – „ Modular system for experimentation in virtual reality“ is universal flexible system created for teaching automated and robotic systems by means of new advanced teaching aids, including virtual reality. It has been created as a specialized website and its possibilities are varied. Particular use depends on creativity of a user. Built-in tools enable to use it adequately when teaching construction of industrial robots, to present their kinematic structure or other properties of individual machines. It also enables to work with machine aggregate. In real-life working the system has been tested for optimization of process layout where the full advantages of virtual reality were taken.

Abstract: Analysis of the torsor evolution in milling process is very important for optimization of the cutting process to achieve high quality of manufacturing, productivity and cost. Our study is based on the analysis of the Mx, My and Mz moments‘ evolution at the tooth tip of the tool during the milling process. A complex experiemntal setup is designed and realized to obtain a three-dimensional response of the mechanical actions. During the tests, the complete torsor of mechanical actions generated by the cutting process were measured by six components dynamometer (forces and moments according to each direction). In this paper a method for tool position determination in milling process is presented, with purpose to transport and evaluate the moments to the tooth tip of the milling cutter.

Abstract: Titanium and its alloys have found wide application in the aerospace, biomedical and automotive industries owing to their good strength-to weight ratio and high corrosion resistance. However, these alloys have very poor machinability, which is attributed to their inherent high strength maintained at elevated temperature and low thermal conductivity leading to high cutting temperatures. This paper presents the findings of an experimental investigation into the effects of cutting speed, feed rate and depth of cut when milling titanium alloy Ti-6Al-4V. The cutting forces were the response variables investigated. This experimental investigation is translated into a mathematical model of cutting forces designed on the basis of the results obtained from this research.

Abstract: In this paper we study the behavior of Rul1 layers deposited by thermal metal spraying to the thermal shock using infrared thermography. It will present thermo grams obtained for the thermal field distribution during heating and the resulting defects. In particular it aims to interfaces defects such as lack of adherence.