Yan H.,China Aerospace Polytechnology Establishment |
Wang T.,China Aerospace Polytechnology Establishment
Proceedings of 2016 Prognostics and System Health Management Conference, PHM-Chengdu 2016 | Year: 2016
In this paper, the issues of derating design of integrated circuit are discussed. The disadvantage of the traditional derating design method is discussed. This paper puts forward the method using Saber to simulate the electric stress of the electronic product, which can improve the accuracy of the result and the speed of the transient stress calculation. The method that uses derating analysis based on Saber simulation is presented. By using this new method, the accuracy of the derating analysis results is greatly improved and the instantaneous stress value can be simulated. To illustrate the method, the implementation to a power supply module of an IC controller is taken as an example. Simulation results are presented to demonstrate the efficiency and accuracy of this new method. © 2016 IEEE.
Li X.D.,China Aerospace Polytechnology Establishment |
Zhang H.,China Aerospace Polytechnology Establishment |
Wu D.L.,China Aerospace Polytechnology Establishment |
Liu X.,Harbin Institute of Technology |
Liu J.Y.,Harbin Institute of Technology
International Journal of Fatigue | Year: 2012
The lock-in infrared thermography technique was adopted to rapidly determine the fatigue limits of two kinds of riveted components, which were both made of 2A12 aluminum alloy and had different magnitudes of interference. The results obtained by the lock-in infrared thermography technique were compared with the existing fatigue limits of 2A12 aluminum alloy, and experimental research based on the staircase method was also carried out. It is shown that the magnitudes of interference and the corresponding initial stresses have important and apparent affections to the results determined by the lock-in infrared thermography technique. © 2011 Published by Elsevier Ltd.
Li H.,China Aerospace polytechnology Establishment
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015
Composite material connected by glue has gained popularity as a replacement for conventional materials and structures to reduce weight and improve strength in the aerospace industry, with the development of material science and structural mechanics. However, the adhesive bonding process is more susceptible to quality variations during manufacturing than traditional joining methods. The integrality, strength and rigidity of product would be broken by disbonding. Infrared thermography is one of several non-destructive testing techniques which can be used for defect detection in aircraft materials. Pulsed infrared thermography has been widely used in aerospace and mechanical manufacture industry because it can offer noncontact, quickly and visual examinations of disbonding defects. However the parameter choosing method is difficult to decide. Investigate the choosing technical parameters for pulse thermograpghy is more important to ensure the product quality and testing efficiency. In this paper, two kinds of defects which are of various size, shape and location below the test surface are planted in the honeycomb structure, they are all tested by pulsed thermography. This paper presents a study of single factor experimental research on damage sample in simulation was carried out. The impact of the power of light source, detection distance, and the wave band of thermography camera on detecting effect is studied. The select principle of technique is made, the principle supplied basis for selection of detecting parameters in real part testing. © SPIE. Downloading of the abstract is permitted for personal use only 2015.
Niu G.,China Aerospace Polytechnology Establishment |
Yang B.-S.,Pukyong National University
Expert Systems with Applications | Year: 2010
This paper proposes an intelligent condition monitoring and prognostics system in condition-based maintenance architecture based on data-fusion strategy. Firstly, vibration signals are collected and trend features are extracted. Then features are normalized and sent into neural network for feature-level fusion. Next, data de-noising is conducted containing smoothing and wavelet decomposition to reduce the fluctuation and pick out trend information. The processed information is used for autonomic health degradation monitoring and data-driven prognostics. When the degradation curve crosses through the specified threshold of alarm, prognostics module is triggered and time-series prediction is performed using multi-nonlinear regression models. Furthermore, the predicted point estimate and interval estimate are fused, respectively. Finally, remaining useful life of operating machine, with its uncertainty interval, are assessed. The proposed system is evaluated by an experiment of health degradation monitoring and prognostics for a methane compressor. The experiment results show that the enhanced maintenance performances can be obtained, which make it suitable for advanced industry maintenance. © 2010 Elsevier Ltd. All rights reserved.
Xuegang L.,China Aerospace Polytechnology Establishment
Procedia Engineering | Year: 2015
At present, customers demand more complex and reliable products to be developed with shorter timeand more cost effectiveness. In the product development process, the traditional approach to reliability specification has been based on unrealistic reliability prediction by usingstandards, such as Mil-Hdbk-217 in the specific case of electronics equipment. In China at the product development stage, the reliability prediction is based on GJB 299.Often, the prediction methodology used assumes an exponential failure rate, meaning that random failures and faults are inevitable. And the reliability prediction method based on GJB 299 is not relevant to product design parameters. There need a new reliability prediction method to address the challenges that we face during the product developmentprocess. In this paper, we firstanalyses the component reliability of the product by reliabilitysimulation based on physics failure theory. Then inputting the results of components reliabilitysimulation and components degradation information to the functional model, we discuss the product reliability by reliability functional simulation. It is shown that we can accurately predict the reliability in the product development process by the proposed method. © 2015 The Authors.
Jin X.,China Aerospace Polytechnology Establishment
Advanced Materials Research | Year: 2014
A common method of debris detection to detect the condition of the engine is to establish the relationship between wearing condition and the elements in debris. To accomplish this aim, the ARIMA and Auto-Regressive models should be set up by analyzing the original time series which is established in accordance with the data of debris. After that, the trend of engine wear in a cycle of overhaul can be verified and the best model can be found depending on the situation of real data of debris. So the original time series can be obtained and the time series model to monitor engine condition can be set up. This paper finally provides a reference for monitoring engine conditions and other familiar fields. © (2014) Trans Tech Publications, Switzerland.
Liu D.,University of Science and Technology Beijing |
Jin L.,China Aerospace Polytechnology Establishment |
Shang X.,University of Science and Technology Beijing
Procedia Engineering | Year: 2012
Equivalent laminate model of the metallic honeycomb structure is given in the present paper firstly. The effective thermal model of the honeycomb core is anisotropic, and both in-plane and thickness direction effective thermal conductivity are deduced using the Swann-Pittman model. The effective mechanical properties of the honeycomb core are determined using the mechanics of materials method, and the effective continuum properties are then used with classical laminate theory to construct an equivalent laminate plate to simulate the response of three-dimensional honeycomb core structure. Then the thermal and free vibration behaviors of the equivalent laminate plate are compared with that of detailed model of the honeycomb core plate using finite element method. Numerical results show that the equivalent model is in good agreement with the detailed model in heat transfer and modal analysis. © 2011 Published by Elsevier Ltd.
Wu C.H.,China Aerospace polytechnology Establishment
Advanced Materials Research | Year: 2014
Face-gear lubrication characteristic is a important indicator to estimate the scuffing load capacity. In this paper, the model of face-gear loaded tooth contact analysis (LTCA) was established, and the load distribution among tooth were calculated, then the entrainment velocity and contact stress calculation equations of face-gear drives were derived. On this basis, face-gear Elastohydrodynamic Lubrication (EHL) dimensionless equations were established. Using the multi-grid algorithm to complete the solution of minimum film thickness and film pressure of face-gear drives. Through the calculation example, lubricant film thickness and film pressure variation in the meshing cycle were expresented. It provideds the technical basis for calculation of scuffing load capacity of face-gear. © (2014) Trans Tech Publications, Switzerland.
Tang B.,Chongqing University |
Jiang Y.,Chongqing University |
Zhang X.,China Aerospace polytechnology Establishment
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2010
Due to the influence caused by random noises and local strong disturbances embedded in signal on empirical mode decomposition (EMD) results, a novel integrated singular value decomposition-morphology filter method is proposed to overcome this shortcoming. And combining with EMD, a feature extraction method is presented. Firstly, reconstruct the original vibration signal in phase space and decompose the attractor track matrix by singular value decomposition (SVD), and then select a reasonable order for noise reduction according to the singular curve. Secondly, filter the de-noised signal by morphology filter. Finally, decompose it by EMD to extract the intrinsic mode functions (IMF) for fault feature extraction. Experimental results and industrial measurement analysi show that this method can extract fault characteristics of rolling bearing effectively, reduce decomposition levels and boundary effect of EMD, and imporve the timeliness and precision thereof. © 2010 Journal of Mechanical Engineering.
Ao L.,China Aerospace Polytechnology Establishment
Engineering Management and Industrial Engineering - Proceedings of the 2014 International Conference on Engineering Management and Industrial Engineering, EMIE 2014 | Year: 2015
The traditional reliability assessment methods are based on failure lifetime data. However, for high reliability and long lifetime products, it is very difficult to obtain their failure lifetime data through life test and accelerated life test. From this view, accelerated performance degradation test is used to verify the reliability of the high reliability and long lifetime products, the pseudo failure data of the products is first confirmed by the performance degradation data in this method, then the reliability of the products can be assessed by the obtained pseudo failure data. The two-step method is always used by the traditional reliability assessment based on accelerated performance degradation and pseudo failure lifetime data. What is the characteristic life of the products under different stress levels is confirmed by the pseudo failure data first, then the accelerated model parameters are confirmed by the regression method with the obtained characteristic life, at last, the reliability of the product under normal stress level can be confirmed by the obtained accelerated model. An integral estimation method for the accelerated performance degradation pseudo failure lifetime data is presented in this paper, the method can make the pseudo failure lifetime data from different stress levels an integral one for statistical analysis, and it can reach higher precision than the traditional two-step method do. © 2015 Taylor & Francis Group, London.