Marek Iwaniec

Low Frequency Damage Analysis of Electric Pylon Model by Fuzzy Logic Application

The paper presents a proposition of a new method for calculating the damage degree of electric pylon model by fuzzy logic application. Damage changes in constructions manifest themselves in small but detectable variations of frequency. The change of the speed of wave propagation, which is associated with the change of the natural frequency in the system, is caused by the deformation of the examined material. This phenomenon can be used for an indirect analysis of the construction damage. The main aim of the article is presentation of the results of the vibrations analyse of the electric pylons. In the preliminary tests the research was conducted on the simulation data of the electric pylon of power grid. Eight construction elements of pylon in different positions were chosen to simulate the damage by decreasing step by step the Youngs modulus. The simulation data was obtained on the basis of the stiffness matrix updated in conjunction with the Finite Element Method. The preliminary research presented in the paper is aiming at creating the software which can monitor in real time the state of electric pylons.

Diagnosis of Supporting Structures of HV Lines Using Magneto-Mechanical Effects

This paper concerns the idea of using magneto-mechanical effects in prophylactic activities to reduce the risk of occurrence of an extensive blackout on high voltage (HV) lines. The subject matter of the paper is related to the event from April 8, 2008, which deprived approximately 600,000 recipients from 18 cities of the West Pomeranian voivodeship of power and caused millions in losses for the national economy. In theoretical considerations, the idea of diagnosing the technical state and level of effort of steel power line towers using the metal magnetic memory method (MMM) is presented, with a consideration of the methodology for obtaining a reference signal from the external magnetic field. The capabilities of the MMM method have been illustrated by examples of active and passive experiments. Finally, the authors indicated the need of IT support of MMM data analysis using a 3D model of the predicted distribution of the magnetic field in the vicinity of the tested object.

Output-Only Identification of Vibratory Machine Suspension Parameters under Exploitational Conditions

The paper concerns model based identification of vibratory machine body suspension system on the basis of dynamic responses measured under exploitational conditions. The research was carried out by means of the restoring force, boundary perturbation and direct parameter estimation techniques which, on the contrary to classical nonlinear system identification methods, requires neither excitation measurements nor linear behaviour of the considered system around an operating point. At the first stage of the research, parameters of the machine body suspension system were identified. Results accuracy was verified by determining percentage relative error of mass estimation with respect to the value calculated based on the machine geometrical and material properties. In the next step, the suspension system was modified by introduction of a nonlinear damping system. Obtained results proved that the assumed identification method is convenient for vibratory machine suspension condition monitoring and determining forces transferred on machine foundations.

Development of vibration spectrum analyzer using the Raspberry Pi microcomputer and 3-axis digital MEMS accelerometer ADXL345

In the paper, the spectrum analyzer of vibration accelerations using the Raspberry Pi microcomputer and 3-axis digital MEMS ADXL345 accelerometer has been developed. The system includes accelerometer driver for Raspberry Pi, software for data acquiring and processing from the acceleration sensor, conversion of the vibration acceleration signals from time domain into frequency domain using DFT, graph plotting of the vibration accelerations and their spectra.

Non-Invasive Methods of Delamination Monitoring in Multi-Layer Structures

In the paper there are discussed the most interesting methods dedicated to frescos structural health monitoring. In the further part two methods and devices for fresco delamination detection developed by authors are presented. In order to enable future automation of developed measurement techniques and autonomic detection of fresco structural defects, the novel measures quantifying the probability of critical condition appearance (the lack of adhesive force) were introduced. Finally, the results of measurements of dynamic characteristics of healthy and delaminated structures are presented.

Transverse vibrations of transmission tower of variable geometrical structure

The research concerns analysis of transverse vibrations of power line transmission tower of variable cross section (changing on its length). Such constructions are subjected simultaneously to internal and external loads, which results in transverse and longitudinal vibrations. These vibrations are described by two partial differential equations of distributed parameters depending on two independent variables. If vibrations are small, the terms connecting equations of transverse and longitudinal vibrations can be neglected as infinitely small with respect to other quantities. Consequently, each vibration can be considered separately.

Numerical simulation of dental implant insertion process

The paper presents the results of the numerical simulation by finite element method of dental implant insertion into mandible.

Development of a system for monitoring vibration accelerations based on the raspberry pi microcomputer and the ADXL345 accelerometer

A system for monitoring and analysis of the vibration acceleration spectrum based on the Raspberry Pi 3 microcomputer and the triaxial digital ADXL345 accelerometer for a real-time operation has been developed. In the process of implementation of the system, the structure and algorithm of functioning of the system for monitoring and analysis of the vibration acceleration spectrum were constructed. The designed structure is based on the modular principle which enables fast improvement of the system. A specialized system software has been developed. It includes a driver for adjusting, collecting and processing the accelerometer data and the corresponding software for plotting vibration acceleration signals in time and frequency domains. Moreover, the software is based on the use of free programs, it features the ability of real-time study of the vibration effect on an object, determining vibration amplitudes and frequencies, plotting graphs of vibration change in time, calculating discrete Fourier transforms and obtaining spectra. The physical model of the system for monitoring and analysis of the vibration acceleration spectrum has been developed. It includes the Raspberry Pi 3, Model B single-board microcomputer, the ADXL345 triaxial digital accelerometer, the liquid-crystal display and is characterized by a low cost and a wide functionality. The system makes it possible to analyze vibration parameters in order to predict and prevent possible accidents, thus reducing the costs associated with the failure of the cutting tools, expensive parts and assemblies of the CNC machine

Composite materials microlevel structure models visualization distributed subsystem based on WebGL

Basing on ray casting method for volume rendering and its implementation by WebGL, the subsystem of composite materials microlevel structure models visualization as a part of composites distributed computer-aided design system was developed.

Diamond-based metal matrix composite effective heat conduction coefficient synthesis microlevel model verification

Basing on comparison of the results of numerical simulation and results of natural experiments the adequacy of the developed diamond-based metal matrix composite effective heat conduction coefficient synthesis microlevel model was confirmed.