Failure Of Electronic Equipment Research Articles

Research on one-dimensional phase change heat transfer characteristics based on instrument compartment structure

To address the issue of electronic equipment failure inside the instrument compartment due to aerodynamic heating during high-speed flight. Combining the heat transfer characteristics of phase change materials, a new instrument compartment structure was proposed as the research subject based on phase change materials. While studying the heat transfer characteristics of this structure, one-dimensional phase change heat transfer theoretical model was constructed based on the Lightfoot integral equation method, and the corresponding analytical solution was obtained. To explore the temperature change law of the instrument compartment structure and verify the rationality of the theoretical model, the new thermal experiment was carried out for the instrument compartment structure. Compared with the aluminum alloy instrument compartment structure, the experimental results show that the instrument compartment structure design based on phase change materials could effectively reduce the temperature of the structure itself, and the experimental data are in good agreement with the theoretical calculation results, which verified the rationality of the theoretical model and provided a scientific basis for the practical application of phase change materials in instrument compartment structures.

Experimental investigation of heat transfer characteristics of inclined aluminium two phase closed thermosyphon

Abstract A reduction in the size of electronic equipment increases the heat generation rate. Failure of electronic equipment occurs if the heat is not dissipated properly. This paper examines the performance of aluminium two-phase closed thermosyphon for cooling electronic equipment. Acetone charged aluminium two-phase closed thermosyphon was fabricated with an inside diameter of 17.05 mm and 1 mm thickness. A series of experimentations were performed for inclination angles of 10°–90° at selected filling ratios of 30, 60 and 100 %, along with heat inputs of 100, 200 and 300 W. The condenser section flow rate of water was maintained constant. Minimum thermal resistance was obtained at a 30° inclination angle for all filling ratios and heat inputs. The evaporator and condenser sections have a maximum heat transfer coefficient at a 30° inclination angle. Thermosyphon, with a 30 % or 60 % filling ratio, performed better than a 100 % filling ratio for all inclination angles and heat inputs. As the heat input was increased, the heat transfer coefficients of the evaporator and condenser section were increased, whereas total thermal resistance decreased. For 300 W heat input and 30 % filling ratio, the minimum thermal resistance at a 30° inclination angle was 0.158 °C/W. It is found that, the same heat input and filling ratio, the maximum heat transfer coefficient value for the evaporator and condenser section at a 30° inclination angle was 1602 W/m2 °C and 5652 W/m2 °C, respectively.

METHOD OF CALCULATING THE UNSTATIONARY TEMPERATURE FIELD PARTS OF THE SPHERICAL FORM OF THE STRUCTURE FLIGHT APPARATUS OF UNMANNED AVIATION COMPLEXES

The design of unmanned aircraft vehicles during operation is exposed to significant temperature effects, which causes changes in the dielectric characteristics of radio technical elements and can lead to failures of on-board radio electronic equipment, as a result of which the task of determining the amount of temperature change in the compartments where the radio electronic equipment is located is performed. At the same time, some external elements of the aircraft vehicle can have complex structures with shapes close to spherical and different thicknesses in each cross-sectional structure.
 There is a need to develop a method for calculating the non-stationary temperature field with the purpose of finding out the real conditions in which all the elements of the aircraft structure work, which would help to determine how the temperature of the structure changes during any flight. At the same time, it is necessary to take into account the three dimensions of temperature gradients on spherical parts of structures of various shapes, namely nose part, rounded wing and others. In them, as a rule, each cross-section of the wall has its own thickness and, according to each cross-section, the temperature distribution along the thickness of the wall will correspond, that is, it is necessary to ensure the redistribution of temperature along the structural element, the calculation of which month. In addition, it is necessary to note that the wall of the aircraft can be multi-layered and the properties of its material can change along with the change in temperature. Considering the fact that it is impossible to take into account all the listed features by analytical methods, when choosing a calculation method, it will be advisable to stop at numerical methods.
 One of the most well-known numerical methods is the finite difference method with an implicit calculation scheme, which has an indisputable advantage for modeling - absolute stability with sufficient changes in time and coordinate steps. We will use the level of thermal conductivity in spherical coordinates in order to increase the accuracy of the calculation, for which solution, after finding out the boundary conditions, we will perform a one-dimensional calculation of the temperature by thickness in each mesh section of the structure, and also perform a calculation of the two-dimensional "heat flow" along the solid between the points, that are located on the same thickness, but have a temperature difference. Thus, when calculating the temperature field, the sphericity and multi-lay redness of the structural elements is taken into account, and the property of the material of the aircraft structure changes depending on the temperature.

О ВРЕДЕ И ПОЛЬЗЕ ДОБАВОК ОРГАНИЧЕСКИХ ВЕЩЕСТВ В ЭЛЕКТРОЛИТЫ ДЛЯ ОСАЖДЕНИЯ СПЛАВА ОЛОВО-ВИСМУТ

Using the example of a tin-bismuth alloy, it was experimentally shown that the addition of organic substances to electrolytes for the electrodeposition of metals and alloys significantly improves the appearance of coatings, but at the same time organic additives are included in the composition of the coatings. The more the concentration of additives in the electrolyte, the better the appearance of the coatings, but the greater the amount of additives contained in the metal (alloy), the more quickly and more noticeable the properties of the coating change over time. Organic additives are gradually desorbed from the coating, faster when heated, and can be transferred and contaminate nearby sensitive elements of electro-optical devices, having a catastrophic effect on their characteristics, reducing reliability, leading to delayed failure of complex electronic equipment

Coverage Blind Area Repair Based on Perceived Multimedia Data Driven in Mobile Wireless Sensor Networks

Wireless sensor networks deploy a large number of wireless sensor nodes in the monitoring area to complete the target monitoring task. The coverage effect is an important index to evaluate wireless sensor networks. The effect of network coverage is realized by the wireless sensor nodes deployed in the monitoring area, because the reasonable deployment of sensor nodes can affect the accuracy, reliability, real time, and integrity of monitoring target data collection. The main purpose of network coverage is to use the least number of wireless sensor nodes to complete the monitoring task of targets in the monitoring area and to avoid the emergence of coverage blind areas. Random node deployment, electronic equipment failure, software error, fire spread, flood, and other phenomena may lead to large-scale failure of wireless sensor nodes. For the failure of some nodes, the phenomenon of coverage blind area appears in the network. In order to repair the coverage blind area in the network, a coverage blind area repair algorithm for wireless sensor networks is proposed in this article. The coverage blind area attracts the nodes, makes the nodes move, and repairs the coverage blind area in the network.

Leakage and assembly of gasket in truck exhaust aftertreatment systems

Leakage of hot exhaust gases in the truck exhaust aftertreatment system potentially leads to secondary damages. The result could be melting of neighboring components or failure of electronic equipment in the vicinity of the leakage. Moreover, major leakage of untreated exhaust gases violates the strict emission standards. Thus investigation of the reliability of the gasket connections in the truck exhaust aftertreatment system is necessary. Preferably, the performance of the gasket is possible to predict during the design process with simulations, so that expensive redesign is avoided. The purpose of this paper is thus to study the safety margin in the gasket connection of a truck exhaust aftertreatment system with experiments and simulations.The gasket installation of a replaceable filter in the truck exhaust aftertreatment system is considered in detail. The filter is replaced regularly, which also puts demands on easy assembly. Finite element simulations, with material data based on tests, are compared to component testing. The outcomes of the work are verified models for simulations and knowledge of the safety factor needed in the gasket connection. Such models are necessary in simulation based engineering, where simulations are utilized to minimize time consuming physical testing in the design process.

Fast Mission Plan Repair Method for Mars Rover Based on State Difference

The uncertainty of Mars environment and the difficulty to predict the failure of electronic equipment will seriously affect the actual effect of the pre-designed plan of the rover on Martian surface, resulting in plan execution failure. To solve this problem, a fast mission plan repair method based on state difference is proposed based on the fact that there is long delay between the Mars rover and the ground station. This method constructs partial states at different times by extracting the key information from the existing plan, lying on the difference between the perception state and the necessary state of action execution. And then the rapid mission plan repair strategy for Mars rover based on the partial state is presented. In this strategy, to improve the efficiency of plan repair, the search space deletion method based on the state difference between the actual state and the partial state is proposed. Simulation results demonstrate that this method can not only improve the efficiency of mission plan repair, but also ensure the plan stability.

Oriented Boron Nitride Nanosheet Films for Thermal Management and Electrical Insulation in Electrical and Electronic Equipment

Insulation failure and insufficient thermal management in electrical and electronic equipment threaten their safe and stable operation and restrict development toward high power and high integratio...

Technology for restoring functional dependencies to determine reliability parameters

The problem of determining the properties of the object by analyzing the numerical and qualitative characteristics of a discrete sample is considered. A method has been developed to determine the probability of trouble-free operation of electronic systems for the case if the interpolation fields are different between several interpolation nodes. A method has been developed to determine the probability of trouble-free operation if the interpolation polynomial is the same for the entire interpolation domain. It is shown that local interpolation methods give more accurate results, in contrast to global interpolation methods. It is shown that in the case of global interpolation it is possible to determine the value of the function outside the given values by extrapolation methods, which makes it possible to predict the probability of failure. It is shown that the use of approximation methods to determine the probability of trouble-free operation reduces the error of the second kind. A method for analyzing the qualitative characteristics of functional dependences has been developed, which allows us to choose the optimal interpolation polynomial. With sufficient statistics, using the criteria of consent, it is possible to build mathematical models for the analysis of failure statistics of electronic equipment. Provided that the volume of statistics is not large, such statistics may not be sufficient and the application of consent criteria will lead to unsatisfactory results. Another approach is to use an approximation method that is applied to statistical material that was collected during testing or controlled operation. In this regard, it is extremely important to develop a method for determining the reliability of electronic systems in case of insufficiency of the collected statistics of failures of electronic equipment.

Effective Length of Counterpoises Connected to Wind Turbine Foundation

Many failures of wind turbine blades and electrical equipment due to powerful lightning strikes have occurred. The lightning-induced wind turbine failures that have occurred in recent years can be classified into two main categories. The first is a mechanical component failure. The second is a failure or malfunction of electric or electronic equipment inside or around the wind turbine due to an increase in the potential of the wind turbine grounding system or the electromagnetic induction caused by the lightning strike. In the latter case, the equipment often fails owing to the increase in the potential of the grounding system, the method of suppressing the potential rise by laying a grounding wire vertically or horizontally to the wind turbine foundation is adopted. We propose an empirical expression for the effective length of counterpoises connected to a large grounding electrode such as a wind turbine foundation, and verify the expression using finite-difference time-domain (FDTD) method.

Радиацияның әсерінен ғарыш аппаратының борттық электроникасының есте сақтау элементтерінің бірліктік істен шығуларын сұлбалық модельдеу

The main purpose of the work is the circuit simulation of failures of on-board electronic equipment of spacecraft (SC) for various purposes under specified conditions and the parameters of the transistors of the memory element during the passage of a single cosmic ray particle (CR). Actuality of the problem. It is known that during the operation of spacecraft for various purposes, as a result of the impact of cosmic rays (CR), on-board electronic systems fail, which leads to abnormal situations, and in some cases to the loss of satellites, for example, KazSat -1 and Phobos-Grunt. Therefore, this paper uses the method of circuit modeling, which is a highly efficient and relatively low-cost method that allows us to evaluate the circuit parameters of the transistors of the memory element during the passage of a single cosmic ray particle. In this paper, we present the results of circuit failure modeling (SEU and SEL) under radiation exposure to storage devices (memory), which was carried out on the CMOS structure, which is the dominant one in the manufacture of ICS.

Уточненная расчетная оценка сбое- и отказоустойчивости критичных изделий ЭКБ с учетом фактической массовой защищенности

Nowadays rocket and space industry enterprises use a simplified method to evaluate failure and fault tolerance of the onboard equipment to single event effects (SEEs), when the calculation is performed for the minimum mass protection thickness (g/cm2 ) of potentially sensitive electronic components determined, as a rule, by the minimum wall thickness of the device under consideration. In this case, all structural elements of the onboard equipment, spacecraft, and neighboring devices are not included, which, in many cases, leads to a significant overestimation of the calculated SEEs frequency especially for large scale integration ICs. Neglecting the actual mass protection may require redundant measures to ensure failure and fault tolerance. The work proposes an improved approach of calculating failure and fault tolerance of sensitive electronic components and onboard equipment to the impact of heavy charged particles and high-energy protons that causes SEEs, which consists in using programs for calculating absorbed doses by the sectorization method in three-dimensional models, which makes possible to determine the minimum, maximum, and average mass protection of electronic components with the complete design of the onboard equipment and spacecraft.

Electrostatically induced voltage generated in ungrounded metal boxes and on a metal box when a charged body moves away from the box

AbstractElectrical discharge and electrostatics are used for the industrial application of a copying machine and electrostatic spraying. However, the electrical discharge and electrostatics occasionally cause malfunction or failure of electronic equipment. When a human body moves in an office, it is electrified up to 10 kV or more. A microelectronic device used in the electronic equipment causes an error owing to the voltage of less than 10 V. When the charged human body moves near the electronic equipment, high induced voltage is generated in the metal box. Comprising electronic equipment, the box is occasionally used at the floating potential of an ungrounded condition. The induced voltage generated for the ungrounded metal box is higher than that generated for the grounded metal box. The results show that the induced voltage generated in an ungrounded metal box is 120% of the inverse polarity against a charged body when the charged body moves away from the box. The induced voltage generated in the ungrounded metal box is higher than that generated on the box. These results would be helpful in designing electronic equipment without malfunctions or failure.

Prediction of thermally induced failure for electronic equipment based on an artificial olfactory system

The failure of electronic equipment causes serious consequences and even catastrophic fires. Abnormal thermal signals are one of the main characteristics of the failure of electronic equipment. Thus, a new method for recognizing and predicting the thermally induced failure states of electronic equipment was proposed, based on an artificial olfactory system (AOS). The AOS recognizes the state of the volatile components released during the early stages of thermally induced failure and uses it to predict the state of health of the electronic equipment. Some typical electronic devices, such as microcomputer units, electronic rectifiers, transformers, and battery modules, were tested with the AOS to recognize the failures indicated by abnormal thermal accumulation. Compared with infrared thermal imagers and gas analyzers, the PEN3 electronic nose was utilized to monitor the status of the devices under different thermal failure scenarios. It was found that infrared thermal imaging was only able to monitor the local surface temperature, and the air temperature in the device chamber changed slowly with the surface temperature of the electronic modules. However, the AOS was able to detect the abnormal change in the whole chamber. Linear discriminant analysis (LDA) and principal component analysis (PCA) were then adopted to investigate the features of thermally induced failure for different thermal states. The results showed that the models obtained both from LDA and PCA were able to distinguish the different states of the electronic devices. Furthermore, a support vector machine model was built, based on the AOS data, to recognize and predict the thermally induced failure processes. All the failure states of the electronic devices caused by thermal simulations were recognized successfully and the prediction accuracy was above 95%. Hence, the experimental results of this research proved that using the AOS, it is feasible to predict the thermally induced failure states of electronic equipment, and the failure of electronic devices can be forecast in advance, before the obvious temperature rise and smoke release. Moreover, the method proposed in this research can also be applied to the prediction of, and warning about, electrical fires, indoor fires, and other thermally induced accidents.

Research on the Determination Method of Acceleration Coefficient in Accelerated Reliability Test of Electronic Equipment

This paper analyzes the relationship between environmental stress and electronic equipment failure, studies the determination method of stress type, combination mode and stress value in reliability accelerated test of electronic equipment. Under given reliability accelerated test section, the acceleration coefficient calculation method of the reliability of electronic equipment are given, it can realize rapid assessment of highly reliable electronic equipment reliability, significantly reduce test time and test cycles, overcome traditional electronic equipment reliability test time is long, high cost, difficult to quickly evaluate the level of reliability of faults.

Space weather climate impacts on railway infrastructure

Space weather is a phenomenon in which radioactivity and atomic particles is caused by emission from the Sun and stars. It is one of the extreme climate events that could potentially has short-term and long-term impacts on infrastructure. The effects of this phenomenon are a multi-fold process that include electronic system, equipment and component failures, short-term and long-term hazards and consequences to astronauts and aircraft crews, electrostatic charge variation of satellites, disruptions in telecommunications systems, navigational systems, power transmission failures and disturbances to the rail traffic and power grids. The critical infrastructures are becoming interdependent to each other and these infrastructures are vulnerable if one of them is affected due to space weather. Railway infrastructure could be affected by the extreme space weather events and long-term evolution due to direct and indirect effects on system components, such as track circuits, electronic components in-built in signalling systems or indirectly via interdependencies on power, communications, etc. While several space weather-related studies focus on power grids, Global Navigation Satellite System (GNSS) and aviation sectors, a little attention has focused towards probability of railway infrastructure disruptions. Nevertheless, disruptions due to space weather on signalling and train control systems has documented but other systems that railway infrastructure dependent upon are not very well studied. Due to the advancements in digitalization, cloud storage, Internet of Things (IoT), etc., that are embedded with electronic equipment are also possible to prone to these effects and it is even become more susceptible to the extreme space weather events. This paper gives a review of space weather effects on railways and other transportation systems and provide some of the mitigation measures to the infrastructure and societal point of view.

Development of a miniature point source pyroshock simulator

Pyrotechnic devices have been widely utilized in various applications: spacecraft, launch vehicles, missiles, and aircraft as well as for stage separation, valve control, and booster separation. However, most pyrotechnic separators generate an intensive mechanical transient response called pyroshock, which can cause catastrophic failures in electronic equipment. In order to validate that the structure or equipment can withstand the generated shock level, pyroshock tests should be performed with properly simulated structural configurations and the shock sources. Most of the previous pyroshock simulators using mechanical excitation have been developed as shock table configurations; they can effectively apply the target shock levels to the test component. However, it is difficult to simulate the pyroshock source in practical structures. In this study, a miniature pyroshock simulator that can easily replace a pyrotechnic device and is adaptable onto the most practical structures was developed. A disk resonator is introduced to control the shock response by changing the first natural frequency of the disk resonator. To excite the disk resonator, we devised a launch device that effectively controls the impact velocity with easy reloading capability. Experiments for 27 different conditions were conducted to identify the control parameters for the shock levels. The developed simulator also showed high repeatability, and it is easy to prepare repeated experiments using the developed shock simulator. This device can easily generate the simulated point-source pyroshock for real structures such as an assembled spacecraft.

EFFICIENCY OF OPERATIONAL DATA PROCESSING FOR RADIO ELECTRONIC EQUIPMENT

The paper deals with the statistical data processing algorithms in operation system of radio electronic equipment. The main purpose is analysis of data processing algorithm efficiency according to the analytical calculations and simulation results. During radio electronic equipment operation failures are possible. These failures affect on the equipment’s technical condition that can deteriorate. In case of condition-based maintenance, it is necessary to detect the time moment of deterioration beginning. Therefore, in this paper the deterioration detection algorithm was developed according to Neyman-Pearson criterion with a fixed sample size. The initial data are times between failures of radio electronic equipment, and these data can be identified by the exponential probability density function. The step-function model was chosen for failure rate change description. To estimate efficiency the operating characteristic was calculated. The simulation based on Monte-Carlo method confirmed the correctness of theoretical calculations.

Reliability Evaluation and Improvement of Islanded Microgrid Considering Operation Failures of Power Electronic Equipment

With the high integration of power electronic technologies in microgrids, the reliability assessment considering power electronic devices has become a hot topic. However, so far no research has considered the impact of the operation failure probability of power electronic equipment on the overall reliability of the microgrid. This paper aims to construct a holistic operation failure rate model of power electronic systems based on the overall reliability assessment of islanded microgrid with high penetration of renewable energy sources (RESs). In addition, to improve the reliability of islanded microgrid, the conventional battery energy storage system (BESS) is replaced by the hybrid energy storage system (HESS). Based on the proposed model, the operation failure models for the power electronic modules in microgrid are built and tested, and then the sensitivity analysis is performed for exploring the influence of various factors on the reliability of the microgrid.

PROCESS IMPACTS ON RELIABILITY OF PRINTED CIRCUIT BOARDS

The paper considers defects that directly affect the quality of the finished product, which includes printed circuit boards and wiring connections. Current problems lead to failures of electronic equipment, which can lead to the failure of complex technical systems with subsequent downtime. Also methods for increasing the reliability of electronic equipment products are proposed, which exclude premature failures of the equipment as a whole. Such failures include breakage of the metallization column during extreme heating of the printed circuit board, poor connection quality of components on the board, absence of a layer between the component and the board. The method of preventing such problems is presented below in the text. Elimination of the above defects can lead to trouble-free operation throughout the warranty period of operation of the equipment at various facilities, including those in the military.