Reliability Analysis Of On-board Circuit Boards Under Multiple Loads Considering Uncertainty

As one of the necessary modes of transportation nowadays,railway transportation often plays an indispensable role in people’s daily life,also improving the reliability of the railway transportation system and reducing its maintenance cost is the key to ensuring safe operation of railway transportation system.In recent years,with the continuous advancement of railway electrification,greening and intelligence,the proportion of circuit boards in railways has increased.Its safe and reliable operation is very important for the normal operation of trains and the entire railway transportation network.Therefore,this article will take a certain vehicle-mounted circuit board as the research object to analyze its reliability and maintenance strategy.The main research contents include the following points:(1)Finite element modeling and simulation was performed on selected circuit boards.First,this article introduces the main functions of the target board,and performs random vibration simulation and thermal simulation on the target circuit board in sequence.Then,the thermal-structural coupling method was used to simulate the thermal cycle of the target circuit board with the result of the thermal simulation as the load.Through simulation,the stress and strain response and temperature distribution of the circuit board can be obtained.(2)The suitable failure physical model was chosen to describe the life distribution of each component in the circuit board.Through comprehensive consideration of cognitive uncertainty and random uncertainty,the probability box model is selected to describe the key parameters in the failure physical model.Then the polynomial chaotic expansion was selected as the proxy model,and the moment information of the life distribution was calculated through the proxy model.Finally the saddle point approximation method was used to calculate the failure probability of the component.Through the comparison between the polynomial chaotic expansion and Monte Carlo,we find that the polynomial chaotic expansion has high calculation accuracy and efficiency.(3)In order to avoid the limitations of experts in constructing fault trees,this paper adopts the method of fault tree modeling based on fault data.Firstly,the Monte Carlo simulation and circuit simulation was used to obtain the decision table for the target circuit.Then the information entropy was used as the criterion to complete and reduce the attributes.According to the data logic analysis method,the fault tree was constructed.Finally the importance of the component was calculated by probability of failure,which can help us to determine the weak points,and provide corresponding suggestions.(4)In the research process of circuit board maintenance strategy decision-making,this article first determines the importance index system of circuit board component maintenance strategy.Considering the existence of a variety of uncertain information and in order to reduce the loss of uncertain information and improve the reliability of decision-making results,this paper considers the consensus reaching process through the group decision analytic hierarchy process to determine the index weight and combine the index into a comprehensive maintenance importance index,and finally based on Possibility to sort them and get the final maintenance strategy.