Solid State Phenomena Vols. 220-221

Abstract: The article presents the methodology, test stand and results of noncontact tests conducted using a laser sensor-equipped system for measuring displacement. The tests were carried out in an attempt to determine the sensitivity of the measurement system to the angular position of the sensor against the surface onto which the laser spot was projected. The scope of investigations constitutes a crucial problem dealing with the determination of tolerance of assembling a laser head in the measurement system for a laser penetrometer used for examining substance consistence. The tests were executed in the measurement range between 5 and 50 mm taking into account 5 angular positions of the laser sensor. The readings of the laser head were referred to the value of displacements adjusted with the use of a micrometric head. In the case of the tested system, the dispersion of measurement deviations was estimated as a function of the measured distance.

Abstract: The paper presents an analysis of tribological processes on the surface layer of large roller bearings parts carried out on bearing steel 100CrMn6. Laboratory tests carried out on roller bearings elements eg. the axle railway wagons exploitation around 600 thousand km. Modern optical microscopy with fiber optic transmission and special software was used; scanning electron microscope was applied to analyze surface stereometry; profilometers made an analyze of seizure of co-working tribological parts: roller – race roller bearings. In addition, the documentation of characteristic tribological processes occurring during the exploitation the bearings was completed. Seizure zones contact surface which occur under high and variable loads and friction were found.

Abstract: There is presented an effect of the changes of the concentration of magnetic particles included in the ferrooil on the dynamic viscosity in the presence of external magnetic field in this paper. The study was conducted in the context of temperature’s changes. In that way, the influence of external physical conditions of ferrooil’s employment was also taken into account. Ferrooil’s dynamic viscosity changes significantly alter the tribological properties and thus its usefulness as a lubricant of the sliding journal bearings. Due to the fact that the ferrooil demonstrates strong magnetic polarity in the presence of an external magnetic field, it is possible to control the viscosity by means of an external magnetic field just by changing the intensity as well as by changing of the concentration of magnetic particles.The paper presents, in the form of graphs, the changes of ferrooil’s dynamic viscosity as a function of temperature and concentration of magnetic particles. The results of research were also subjected to analysis.

Abstract: The paper presents an approach to develop a system for fatigue crack growth monitoring and early damage detection in the PZL – 130 ORLIK TC II turbo-prop military trainer aircraft structure. The system functioning is based on elastic waves propagation excited in the structure by piezoelectric PZT transducers. In the paper, a built block approach for the system design, signal processing as well as damage detection is presented. Description of damage detection capabilities are delivered in the paper and some issues concerning the proposed signal processing methods and their application to crack growth estimation models are discussed. Selected preliminary results obtained during the Full Scale Fatigue Test thus far are also presented.

Abstract: The present paper proposes an analytical method for determining the course (path) of crack propagation. A fatigue crack arises at the tooth root of a cylindrical geared wheel due to loading connected with gear work conditions. The cracking model was built using the adequate NASGRO2/3 formula; moreover, for comparison purposes, Forman and Paris-Erdogan’s laws were utilized. The length of an increase (propagation) in the crack was directly calculated by means of the boundary element method.

Abstract: The article presents one of the concepts of the performance of keeping up the movement of a gantry behind the load. For reaching this solution, a PID controller has been applied. The worked out control algorithm has been implemented and tested employing a 3D Crane 3D. The results of experimental research have been compared with the findings of numerical simulations.

Abstract: The paper presents the first results of research on an artificial cochlea based on a mechanical filter bank that could be produced by MEMS (Micro Electro Mechanical Systems) technologies and power supplied by energy harvesting systems. First, the basic configuration of the artificial cochlea proposed by our team is described. Then, the configuration of mechanoelectrical transducers (polycrystalline diffused piezoresistors) displayed in the first experiment is offered. Finally, the eigenfrequencies of resonant membranes calculated employing finite element systems Ansys and CoventorWare are introduced.

Abstract: The paper presents an application of resistive ladder sensors (or resistive crack gages) for health monitoring of an aircraft structure. An experiment was conducted during a Full Scale Fatigue Test (FSFT) of PZL 130 ORLIK TC II turbo-prop military trainer. The sensor can be successively used to detect and quantify fatigue cracks. It is a parametric transducer, similar to foil strain gages. Differences in shape of the measuring grid can be noticed. Principle of operation, sensor’s characteristics as well as block diagram of measurement system is presented in the paper. Also examples, both laboratory and FSFT data are delivered to prove surface crack detection capabilities. Simultaneously with new data collection, some investigation is carried out, connected with customize hardware elaboration, signal processing and structure-sensor integration method, what is briefly described.

Abstract: This paper presents application of magnetovision scanning system for detection of dangerous objects in weak magnetic fields. Measurement system was developed to study the magnetic field vector distributions. The measurements of the Earth’s field disturbances caused by dangerous ferromagnetic objects were carried out. The ability for passive detection of hidden dangerous objects and determine their location was demonstrated.

Abstract: A number of different mechanisms and devices may involve sliding-friction surfaces. The issues of service life and its prediction for the details of such surfaces have always been of particular importance. The article determines the most suitable wear calculation model that allows considering the set of parameters necessary for calculating slide-friction pair. The offered model is based on the application of the theories of several branches of sciences. Since the wear process is variable and many-sided, it is influenced by numerous different parameters, for example, surface geometry (roughness, waviness, form deviation, etc.), physical and mechanical conditions of the upper layer, material components, wear regime, wear temperature, etc.