Solid State Phenomena Vol. 199

Abstract: In the article, new method of monitoring of rotor machine blades technical condition is presented. This method is based on diagnostic model φ_T12T01 [ which uses phase shift difference of signal fragments resulting from blade operation y (t) during blade recession from sensor and during approach of blade tip towards the sensor as well as signal of its environment x (t) described using proper distribution. The assumed diagnostic model also indirectly includes actual blade environment x (t) without necessity of its measurement [3,. Contactless inductive sensor constantly measures the signal of operating blade transition below the sensor. However, several difficulties with determination of last sample of blade receding from the sensor with first sample of blade approaching the sensor exist. Additionally the problem occurs with measurement of space between blades. So far, the case was solved by use 90% of this space range (in order to eliminate the overlapping of adjacent blades signals). Hence the problem of assessment of measurement period breadth on obtained models (images) of blades. The possibility of blade damage detection by analysis of less than 90% signal course was tested.

Abstract: In the operation process, a complex method evaluating technical condition and regulatory status (activities) of the bearing system is used. The method of determination of technical parameters and operating status is known. This is achieved through the interaction of two coupled equations and [2, 3, 7]. It was demonstrated that, on the basis of waveform parameters of technical condition and operating status (respectively), the identification of parametric and momentary damage can be carried out. During the identification process of parametric and momentary damage, it is assumed that damage arises when a parameter threshold value at the time of operation is greater than current permissible value. It is shown how the threshold value of the parameter and its current permissible value, taking into account the number of measurements, are determined.

Abstract: The author of this article considers new approach based on operational reliability models, written in the form of matrices and digraphs methods. At a core of the method the author used the theory of systems and their decomposition consistent with the FMEA methodology [, that allows a simplification of the distribution of elements within the system into smaller parts having a greater susceptibility to the error analysis and forecasting of their states. The method mainly refers to decentralized systems, linked via reciprocal relationships (that can be applied to manufacturing work centres, transport lines, etc.), containing subsystems that use the control, power, noise and mass flows streams. Article includes also main assumptions of described method, realizability studies, application areas and significant restrictions.

Abstract: Author of this article presents an authorship reliability model of a AC-asynchronous drive written in accordance with assumptions of the multilevel prognosis system based on matrices and digraphs methods. Described model take advantage of knowledge gathered from specialists on the basis of their experience. It is worth to stress that parameters of the reliability model of the AC-drive meet the requirements of units utilized in case of distributed drives. Each change of its application range requires a modification of internal parameters, but the functional structure remains without any variations, because presented reliability model has been based on the functional structure. An intention of the author is focused on an elaboration of a collection of reliability models [ of distributed drives components, prepared in accordance with the multilevel system of prognosis based on matrices and digraphs methods. The model has been specified to the level of the independent subsystem. This approach allows the use of this model in the analysis of complex systems, consisting of separated drive subsystems, which meet the requirements of the method. Using multilevel prediction models should be possible in all applications of electric drives, regardless of purpose functions.

Abstract: The main aim of the work is determination of numerical and numerical-analytical methods of evaluation of fatigue strength and life of geared tooth considering tooth breakage phenomenon. The discussed tasks were performed using the following tools: dual boundary element method, BEASY package as well as fracture mechanics

Abstract: The paper presents a multi-dimensional harmonic balance analysis utilized to study the vibration responses of the cracked rotor subject to gravity, unbalance and an additional lateral harmonic force generated by an active magnetic bearing. The nonlinear terms resulting from the shaft crack are included via an alternating frequency/time domain (AFT) method. The example addressed in this paper is a simple rotor modeled by using the rigid finite element (RFE) approach. Combination frequencies are recognized as evident symptoms of the shaft crack.

Abstract: Modern air transportation systems prove to be of numerous advantages, but there is always a risk of an air accident. Air accidents occur for many and various reasons. The group of aircraft accidents due to engineering causes, includes events directly resulting from the malfunctioning of the hydraulic circuit that controls high-lift devices. In this paper presented is a mathematic model of dynamic behaviour of a wing flap system, which has been intended to enable simulation tests with account taken of operation-induced failures/damages. Major emphasis has been put on analyses of the simulation-tested dynamics of a flap-driving hydraulic circuit, with account taken of the following defects: changes in compressibility of hydraulic fluid, internal leakages in the hydraulic cylinder, external leaks of hydraulic fluid.

Abstract: During diagnostic thresholds research, sequence of numbers emerging from proper measurements, are analysed. These are sequences characterizing environment (e.g. amount of hours worked sequence x and sequence of numbers emerging from diagnostic signal measurement sequence y). Hence, two sequences exist: {x₀, x₁,, x_m} and {y₀, y₁,, y_m}. Relation between these sequences might be determined by Cauchy product. The Cauchy product can significantly expand opportunities of applications of signal processing and analysis. Auto and cross Cauchy products of signals as well as quotients and subtraction result of the diagnostic and environment signals, for the standard condition and the condition resulting from the current diagnosis can be determined. These allow to make diagnostics more precise, particularly in case of small number of measurements, and low accuracy of the diagnostics thresholds determined from them.

Abstract: The article presents the research results referring to the analysis of the influence of finish treatment ( lathing, grinding, burnishing) on the contact fatigue of steel applied to marine pump shafts. The research was performed on a roller 40 mm in diameter made of 304L stainless steel. Within the research, the optimalization of burnishing technological parameters was conducted on account of the minimalization of Ra surface roughness coefficient as well as the maximalization of S_U degree of surface layer relative hardness [. The multi criteria optimalization conducted by min-max method [ with regard to minimum surface roughness as well as maximum degree of surface layer hardness demonstrated that burnishing process should be carried out at the following technological parameters: burnishing force 1.1 kN, burnishing speed 35 m/min, feed 0.13 mm/rev. In addition, the influence of the burnisher passes number on the surface layer quality was determined [.The paper will present the research results of contact fatigue examination of samples after finish machining.

Abstract: In this paper, a method of evaluation of the turbojet engine regulation condition in flight, based on information from its ground tests was presented. The tested engine was presented by the single comprehensive model which links input (in form of the modified signal mp4) and engine output (in form of the modified signal np2). Changes of the model parameters following during its operation can be defined using changes of the proposed simulation model parameters describing the engine operation both in flight and during ground tests.