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Coupling damage and reliability model of low-cycle fatigue and high energy impact based on the local stress–strain approach

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Chinese Journal of Aeronautics 2014年第4期27卷 846-855页

作者： chen Hongxia chen yunxia Yang Zhou School of Reliability and Systems Engineering Beihang University

Fatigue induced products generally bear fatigue loads accompanied by impact processes,which reduces their reliable life rapidly. This paper introduces a reliability assessment model based on a local stress–strain approach considering both low-cycle fatigue and high energy impact *** coupling relationships between fatigue and impact are given with effects of an impact process on fatigue damage and effects of fatigue damage on impact performance. The analysis of the former modifies the fatigue parameters and the Manson–Coffin equation for fatigue life based on material theories. On the other hand, the latter proposes the coupling variables and the difference of fracture toughness caused by accumulative fatigue damage. To form an overall reliability model including both fatigue failure and impact failure, a competing risk model is developed. A case study of an actuator cylinder is given to validate this method.

关键词： Coupling damage Fatigue High-energy impactLow-cycle Local stress-strain Reliability Strain rate

Model-driven degradation modeling approaches:Investigation and review

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Chinese Journal of Aeronautics 2020年第4期33卷 1137-1153页

作者： Rui KANG Wenjun GONG yunxia chen School of Reliability and Systems Engineering Beihang UniversityBeijing 100083China

The second law of thermodynamics implies that any animate and inanimate systems degrade and inevitably stops *** is irreversible over time that can be labeled as‘‘the degradation arrow of time".From perspective of products’reliability design,it is essential to build appropriate models of describing the degradation arrow of *** current modeling approaches mainly include the model-driven(having assumed forms based on cognitive experience of mankind)and data-driven(using data learning techniques without form hypothesis)*** this paper,we just investigate and review the model-driven degradation approaches,hoping to provide suggestions of the model construction or selection for scholars or ***,for the single mechanism,degradation law models and stochastic process models are classified as separately depicting the tendency and fluctuation of *** the degradation law model,we propose the concept of meta-models as original types for various personal *** the stochastic process model,two main types including the non-monotonic and monotonical types are ***,four multi-mechanism degradation types are discussed,that are competitive degradation,multi-stage degradation,coexistence of degradation and impact,and coexistence of degradation and ***,for the multi-performance degradation,independent and coupling models are *** forms,connotations,applicability and insufficiency of these models are described with a series of examples from the literature and our own *** final explicit suggestions about the potential future work are provided for the development of new degradation models.

关键词： Degradation law Degradation process Meta-models Multi-mechanism Multi-performance

Review and propositions for the sliding/impact wear behavior in a contact interface

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Chinese Journal of Aeronautics 2020年第2期33卷 391-406页

作者： yunxia chen Wenjun GONG Rui KANG School of Reliability and Systems Engineering Beihang UniversityBeijing 100083China

A thermal-solid-liquid complex operational environment induces structural interface developing a typical coupling sliding/impact wear *** results in contact damage until systems fail,which may cause significant economic losses and catastrophic *** key point of solving this problem is to reveal the coupling damage mechanism of the sliding/impact behavior in typical systems and life characterization under a complicate evolving *** has been a hot topic in the area of mechanical *** main work in this paper can be concluded as ***,the main industries in which the"sliding/impact behavior"takes place have been ***,existing studies on the wear mechanism and degree analysis are presented,which includes surface morphology analysis,wear debris analysis,and wear degree ***,existing problems in theoretical modeling and experiments in current research are summarized,so as to point out a bright direction for future research on wear *** include interface contact modeling,mathematic coupling mechanism modeling,wear equation establishment,and wear life characterization,which can provide some new ideas for improving the existing studies on the sliding/impact wear behavior.

关键词： Contact interface Coupling mechanism Life prediction Sliding/impact wear behavior Wear equation

Validation methodology for distribution-based degradation model

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Journal of Systems Engineering and Electronics 2012年第4期23卷 553-559页

作者： yunxia chen Zhiguo Zeng Rui Kang School of Reliability and Systems Engineering Beihang UniversityBeijing 100191E R.China

Distribution-based degradation models （or graphical approach in some literature） occur in a wide range of applications. However, few of existing methods have taken the validation of the built model into consideration. A validation methodology for distribution-based models is proposed in this paper. Since the model can be expressed as consisting of assumptions of model structures and embedded model parameters, the proposed methodology carries out the validation from these two aspects. By using appropriate statistical techniques, the rationality of degradation distributions, suitability of fitted models and validity of degradation models are validated respectively. A new statistical technique based on control limits is also proposed, which can be implemented in the validation of degradation models＇ validity. The case study on degradation modeling of an actual accelerometer shows that the proposed methodology is an effective solution to the validation problem of distribution-based de qradation models.

关键词： degradation model distribution-based degradationmodel graphical method model validation control limits.

Coupling behavior between adhesive and abrasive wear mechanism of aero-hydraulic spool valves

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Chinese Journal of Aeronautics 2016年第4期29卷 1119-1131页

作者： chen yunxia Gong Wenjun Kang Rui School of Reliability and Systems Engineering Beihang University

Leakage due to wear is one of the main failure modes of aero-hydraulic spool valves. This paper established a practical coupling wear model for aero-hydraulic spool valves based on dynamic system modelling theory. Firstly, the experiment for wear mechanism verification proved that adhesive wear and abrasive wear did coexist during the working process of spool valves. Secondly coupling behavior of each wear mechanism was characterized by analyzing actual time-variation of model parameters during wear evolution process. Meanwhile, Archard model and three-body abrasive wear model were utilized for adhesive wear and abrasive wear, respectively. Furthermore, their coupling wear model was established by calculating the actual wear volume. Finally, from the result of formal test, all the required parameters for our model were obtained. The relative error between model prediction and data of pre-test was also presented to verify the accuracy of model, which demonstrated that our model was useful for providing accurate prediction of spool valve's wear life. (C) 2016 The Authors. Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics.

关键词： Abrasive wear Adhesive wear Aero-hydraulic spool valves Coupling effects Dynamic model

Using PoF models to predict system reliability considering failure collaboration

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Chinese Journal of Aeronautics 2016年第5期29卷 1294-1301页

作者： Zeng Zhiguo Kang Rui chen yunxia Chair on Systems Science and Energetic Challenge Fondation Electricitéde France (EDF) Centrale Supélec Université Paris-Saclay School of Reliability and Systems Engineering Beihang University

Existing Physics-of-Failure-based （PoF-based） system reliability prediction methods are grounded on the independence assumption, which overlooks the dependency among the compo- nents. In this paper, a new type of dependency, referred to as failure collaboration, is introduced and considered in reliability predictions. A PoF-based model is developed to describe the failure behavior of systems subject to failure collaboration. Based on the developed model, the Bisection-based Reliability Analysis Method （BRAM） is exploited to calculate the system reliability. The developed methods are applied to predicting the reliability of a Hydraulic Servo Actuator （HSA）. The results demonstrate that the developed methods outperform the traditional PoF-based reliability prediction methods when applied to systems subject to failure collaboration.

关键词： Dependency Failure collaboration Physics-of-failure Reliability modeling Reliability prediction

Generation of Accelerated Stability Experiment Profile of Inertial Platform Based on Finite Element

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Chinese Journal of Aeronautics 2012年第4期25卷 584-592页

作者： chen yunxia HUANG Xiaokai KANG Rui School of Reliability and System Engineering Beihang UniversityBeijing 100191China

The residual stress generated in the manufacturing process of inertial platform causes the drift of inertial platform parameters in long-term storage ***,the existing temperature cycling experiment could not meet the increased repeatability technical requirements of inertial platform *** order to solve this problem,in this paper,firstly the Unigraphics（UG） software and the interface compatibility of ANSYS software are used to establish the inertial platform finite element ***,the residual stress is loaded into finite element model by ANSYS function editor in the form of surface loads to analyze the *** then,the generation based on ANSYS simulation inertial platform to accelerate the stability of experiment profile is achieved by the application of the analysis method of orthogonal experimental design and ANSYS thermal-structural *** optimum accelerated stability experiment profile is determined finally,which realizes the rapid,effective release of inertial platform residual *** research methodology and conclusion of this paper have great theoretical and practical significance to the production technology of inertial platform.

关键词： inertial platform residual stresses accelerated stability orthogonal experimental design ANSYS thermal-structural coupled analysis

Methods to determine stress profile in ALT based on theoretical life models

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Chinese Journal of Aeronautics 2015年第3期28卷 729-736页

作者： chen yunxia Jing Hailong Liao Xun Kang Rui School of Reliability and Systems Engineering Beihang University

Abstract With the recent products being more reliable, engineers cannot obtain enough failure or degradation information through the design period and even the product lifetime, therefore, accel erated life test （ALT） ihas become the most popular way to quantify the life characteristics of prod ucts. Test design is the most essential topic, such as testing duration, stress profile, data inference, etc. In this paper, a method and procedure based on theoretical life models is proposed to determine the accelerated stress profile. Firstly, the method for theoretical life calculation is put forward based on the main failure mechanism analysis and the theoretical life models. Secondly, the method is pro vided to determine the accelerated stress profile, including the method to determine the accelerated stress types and the stress range on the basis of the main failure mechanism analysis, the method to determine the acceleration factor and the accelerated stress level based on life quantitative calcula tion models, and the collaborative analysis method of the accelerated test time while taking the mul tiple failure mechanisms into consideration. Lastly, the actuator is taken as an example to describe the procedure of the method and the engineering applicability and the validity are verified.

关键词： Acceleration factor Accelerated stress profileALT Failure mechanisms Main failure mechanismanalysis Theoretical life models

Consistency analysis of accelerated degradation mechanism based on gray theory

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Journal of Systems Engineering and Electronics 2014年第2期25卷 322-331页

作者： yunxia chen Hongxia chen Zhou Yang Rui Kang Yi Yang School of Reliability and Systems Engineering Beihang University

A fundamental premise of an accelerated testing is that the failure mechanism under elevated and normal stress levels should remain the same. Thus, verification of the consistency of failure mechanisms is essential during an accelerated testing. A new consistency analysis method based on the gray theory is pro- posed for complex products. First of all, existing consistency ana- lysis methods are reviewed with a focus on the comparison of the differences among them. Then, the proposed consistency ana- lysis method is introduced. Two effective gray prediction models, gray dynamic model and new information and equal dimensional （NIED） model, are adapted in the proposed method. The process to determine the dimension of NIED model is also discussed, and a decision rule is expanded. Based on that, the procedure of ap- plying the new consistent analysis method is developed. Finally, a case study of the consistency analysis of a reliability enhancement testing is conducted to demonstrate and validate the proposed method.

关键词： enhancement test mechanism consistency gray the-ory smart electricity meter.