28 research outputs found

    The analysis of defects propagation in navigating electronic devices

    Get PDF
    Defects in the form of microcracks in ??8?12 contacts of passive electronic components of navigating devices operating at different temperatures and pressure were analyzed. Research results have demonstrated the possibility of early prevention of potential accidents. Microscopic studies are systematized depending on various physical and chemical influences on devices. The mathematical model for defects definition in local points of contacts with an error of about 5 – 7.5 % has been applie

    Failure analysis of destructive coils

    Get PDF
    The failure of the destructive pulsed power coils has been investigated. The destructive coil is the key element of the laboratory system which generates half-period abrupt magnetic field pulses with the amplitudes up to 45 T. The transient coupled non-linear magneto-mechanical model has been applied for finite element simulations. The mechanical behavior and operation threshold of the coil have been examined. It has been found that operation threshold of the coil with relatively thin cylindrical reinforcement could be characterized by the opening of the plastic hinge and estimated numerically. Good agreement with experimental results has been observe

    The analysis of defects propagation in navigating electronic devices

    Get PDF
    Defects in the form of microcracks in ??8?12 contacts of passive electronic components of navigating devices operating at different temperatures and pressure were analyzed. Research results have demonstrated the possibility of early prevention of potential accidents. Microscopic studies are systematized depending on various physical and chemical influences on devices. The mathematical model for defects definition in local points of contacts with an error of about 5 – 7.5 % has been applie

    Dislocation avalanches and strain bursts in the boards of electronic equipment

    Get PDF
    Dislocation avalanches and strain bursts in the boards of radio-engineering equipment were investigated. For that purpose a cascade of navigation devices boards was installed on the vibration stand and experiments were performed in the 0.5 – 10 Hz vibration range at 0 – +45 °C temperature. Amplitude method was applied to determine the coordinates of localized sources of acoustic emission and research of mechanical stress in local points of material was performed using axial compression tests on tensile machine. The results indicate the initial increase in tension and relative deformation and further their decrement. The acquired experimental data on acoustic emission reflect the formation of microcracks and the instability of mechanical tension, its avalanche and explosive tendency in the material when the micro volumes of material are torn

    Failure analysis of destructive coils

    Get PDF
    The failure of the destructive pulsed power coils has been investigated. The destructive coil is the key element of the laboratory system which generates half-period abrupt magnetic field pulses with the amplitudes up to 45 T. The transient coupled non-linear magneto-mechanical model has been applied for finite element simulations. The mechanical behavior and operation threshold of the coil have been examined. It has been found that operation threshold of the coil with relatively thin cylindrical reinforcement could be characterized by the opening of the plastic hinge and estimated numerically. Good agreement with experimental results has been observe

    Tanie urządzenie doświadczalne do oceny wpływu dynamicznych obciążeń mechanicznych na moduły fotowoltaiczne

    No full text
    The efficiency of modern photovoltaic systems is strongly reduced when the crystalline structure of the solar cells is being damaged due to extensive mechanical stress caused by climatic factors such as heavy wind or snow. This work is focused on the investigation of the cyclic dynamic mechanical loads required to alter the efficiency of typical solar panels in order to simulate various weather conditions and investigate the reliability of the solar panels when they are subjected to stress. Experimental setup is described in the study. During experiments the solar panels have been treated up to 40 Hz vibrations with the maximum magnitude of the shift of the solar panel in the range of 0.3 mm. Simulation model of the characteristic frequencies during vibrations is also presented in this work. The experimental vibration spectrum has also been determined. The acquired experimental data showed appearance of micro fractures in the crystalline structure of the photovoltaic modules and allowed estimation of the average reliability of a typical modern photovoltaic module in harsh weather conditions. The setup could be successfully applied for express testing of solar panels and investigation of the susceptibility of photovoltaic modules to mechanical stress.Sprawność współczesnych instalacji fotowoltaicznych drastycznie spada, kiedy struktura krystaliczna ogniw słonecznych ulega uszkodzeniu z powodu dużych naprężeń mechanicznych powodowanych przez czynniki klimatyczne, takie jak silny wiatr lub śnieg. Niniejsza praca skupia się na badaniu cyklicznych dynamicznych obciążeń mechanicznych niezbędnych do obniżenia sprawności typowych paneli słonecznych w celu symulacji różnych warunków pogodowych oraz badania niezawodności paneli słonecznych poddanych oddziaływaniu czynników zewnętrznych. W publikacji opisano układ doświadczalny. W ramach doświadczeń, panele słoneczne zostały poddane drganiom do 40 Hz przy maksymalnej wielkości przesunięcia panelu słonecznego w zakresie do 0,3 mm. W pracy omówiono także model symulacyjny częstotliwości charakterystycznych w czasie drgań. Określono widmo drgań doświadczalnych. Uzyskane dane doświadczalne wykazały pojawienie się mikropęknięć w strukturze krystalicznej modułów fotowoltaicznych i pozwoliły na oszacowanie średniej niezawodności typowego współczesnego modułu fotowoltaicznego w trudnych warunkach pogodowych. Układ może być z powodzeniem wykorzystywany dla potrzeb doraźnego testowania paneli słonecznych oraz badania podatności modułów fotowoltaicznych na naprężenia mechaniczne

    Magneto-Permeabilization of Viable Cell Membrane Using High Pulsed Magnetic Field

    No full text

    DISLOCATION AVALANCHES AND STRAIN BURSTS IN THE BOARDS OF RADIO-ENGINEERING EQUIPMENT

    No full text
    The aim of this work is to investigate the influence of vibrations on the material of the board. For that purpose a cascade of navigation devices boards was installed on the vibrational stand. Experiments were performed in the 0,5–10 Hz vibrational diapason range; 0–3 V voltage range; 0 – +45 °C allowed temperature range. Amplitude method was applied to determine the coordinates of localized sources of acoustic emission. The results indicate the initial increase in tension and relative deformation and further their decrement. Growth rate reduction of mechanical stress dσ/dε is due to destruction of material structure. The receiving piezo converter based on ЦТС-19 ceramics and a waveguide that was in acoustic contact with the sample were used during experiments. The acquired experimental data on acoustic emission reflect the formation of microdefects and the instability of mechanical tension, its avalanche and explosive tendency in the material when the microvolumes of material are torn
    corecore