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Reliability analysis of ship structure system with multi-defects

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Science china(Physics,Mechanics & Astronomy) 2010年第11期53卷 2113-2124页

作者： AN Hai 1,AN WeiGang 1 & ZHAO WeiTao 2.1 school of Aerospace and Civil Engineering,Harbin Engineering university,Harbin 150001,{2. 2.school of aeronautics and astronautics,Shenyang Institute of Aeronautical Engineering,Shenyang 110034,{2. 1. school of Aerospace and Civil Engineering Harbin Engineering University Harbin 150001 China2. School of Aeronautics and Astronautics Shenyang Institute of Aeronautical Engineering Shenyang 110034 China

This paper analyzes the influence of multi-defects including the initial distortions,welding residual stresses,cracks and local dents on the ultimate strength of the plate element,and has worked out expressions of reliability calculation and sensitivity analysis of the plate *** analysis is made for the system with multi-defects plate *** mechanism,failure paths and the calculating approach to global reliability index are also worked *** plate elements with multi-defects fail,the formula of reverse node forces which affect the residual structure is deduced,so are the sensitivity expressions of the system reliability *** ensures calculating accuracy and rationality for reliability analysis,and makes it convenient to find weakness plate elements which affect the reliability of the structure ***,for the validity of the approach proposed,we take the numerical example of a ship cabin to compare and contrast the reliability and the sensitivity analysis of the structure system with multi-defects with those of the structure system with no *** approach has implications for the structure design,rational maintenance and renewing strategy.

关键词： initial distortions welding residual stresses cracks and local defects ultimate strength reverse node forces sensitivity expression reliability analysis

On the general expressions of finite Hankel transform

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Science china(Physics,Mechanics & Astronomy) 2010年第11期53卷 2125-2130页

作者： JIANG Quan 1,2.& GAO CunFa 1 1 College of Aerospace Engineering,Nanjing university of aeronautics and {2.,Nanjing 2.0016,china 2.school of Civil Engineering,Nantong university,Nantong 2.6019,china 1. College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China2. School of Civil Engineering Nantong University Nantong 226019 China

The general expressions of finite Hankel transform are naturally deduced with the help of the property of Bessel *** equations in this paper can degenerate into three kinds of boundaries since all the coefficients in the boundary conditions are taken into *** results can be adopted in solving physics problems involving the finite Hankel transform.

关键词： hankel transform bessel function finite integral

Bursting of Morris-Lecar neuronal model with current-feedback control

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Science china(Technological Sciences) 2009年第3期52卷 771-781页

作者： DUAN LiXia1, LU QiShao2.& CHENG DaiZhan3 1 College of Science, North china university of Technology, Beijing 100144, china 2.school of Science, Beijing university of aeronautics and astronautics, Beijing 100191, china 3 Institute of Systems Science, Chinese Academy of Sciences, Beijing 100190, china College of Science North China University of Technology Beijing 100144 China school of Science Beijing University of Aeronautics and Astronautics Beijing 100191 China Institute of Systems Science Chinese Academy of Sciences Beijing 100190 China

The Morris-Lecar (ML) neuronal model with current-feedback control is considered as a typical fast-slow dynamical system to study the combined influences of the reversal potential VCa of Ca2. and the feedback current I on the generation and transition of different bursting oscillations. Two-parameter bifurcation analysis of the fast subsystem is performed in the parameter (I, VCa)-plane at first. Three important codimension-2.bifurcation points and some codimension-1 bifurcation curves are obtained which enable one to determine the parameter regions for different types of bursting. Next, we further divide the control parameter (V0, VCa)-plane into five different bursting regions, namely, the "fold/fold" bursting region R1, the "fold/Hopf" bursting region R2. the "fold/homoclinic" bursting region R3, the "subHopf/homoclinic" bursting region R4 and the "subHopf/subHopf" bursting region R5, as well as a silence region R6. Codimension-1 and -2.bifurcations are responsible for explanation of transition mechanisms between different types of bursting. The results are instructive for further understanding the dynamical behavior and mechanisms of complex firing activities and information processing in biological nervous systems.

关键词： neuron bursting bifurcation fast-slow dynamics analysis codimension

An output delay approach to fault estimation for sampled-data systems

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Science china(Information Sciences) 2012年第9期55卷 2128-2138页

作者： WEN ChengLin 1,QIU AiBing 2.& JIANG Bin 3 1 Institute of Information and Control,Hangzhou Dianzi university,Hangzhou 310018,china 2.{2. of Electrical Engineering,Nantong university,Nantong 2.6019,china 3 College of Automation Engineering,Nanjing university of aeronautics and astronautics,Nanjing 2.0016,china 1. Institute of Information and Control Hangzhou Dianzi University Hangzhou 310018 China2. School of Electrical Engineering Nantong University Nantong 226019 China3. College of Automation Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

The problem of fault estimation for a class of non-uniformly sampled-data systems is investigated from the time delay point of view in this ***,the output delay approach is employed to model the sampled-data system as a continuous-time one with time-varying delay ***,based on the analysis of the inapplicability of the adaptive fault diagnosis observer in such class of time-delay systems,a novel augmented fault estimation observer design method is proposed to guarantee the exponential convergence of the estimation ***,an extension to the case of time varying fault estimation for the noisy sampled-data systems is ***,simulation results of a flight control system are presented to demonstrate the effectiveness of the proposed method.

关键词： fault estimation non-uniformly sampled-data augmented observer output delay

VECTRIX AND SOME OF ITS PROPERTIES SUITED TO FLIGHT DYNAMICS

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Chinese Journal of aeronautics 1996年第2期9卷 92-97页

作者： Chen Wanchun Xiao Yelun (school of astronautics, Beijing {2. of aeronautics and astronautics, Beijing, china, 100083) school of astronautics Beijing Univ. Aero. and Astronaut. Beijing 100083 China

A vectrix cross-product operator identity is presented which shows thesymmetrical relationship between a column matrix and a vectrix. The kinematics ofvectrices and other commonly used relations are then easily obtained with it. The timederivative of the transformation matrix is extended to a more general form ofexpression. The results can be used conveniently in the modeling of flight dynamics inwhich many reference frames must be used.

关键词： vectors (mathematics) matrix methods operators (mathematics),kinematics dynamic models

Stability on Finite Time interval andTime-Dependent Bifurcation Analysis ofDuffing's Equations

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Communications in Nonlinear Science and Numerical Simulation 1999年第4期4卷 268-271页

作者： Cuncai HUA Qishan LU(school of Science, Beijing university of {2. and astronautics, Beijing 100083,china) school of Science Beijing Univ. Aero. and Astronaut. Beijing 100083 China

IntroductionInPhysics,MechanicsandEngineering,ChemistryandLifeScienceetc.,thereealstbfforcationproblemsm***etimepassingthrought... 详细信息

IntroductionInPhysics,MechanicsandEngineering,ChemistryandLifeScienceetc.,thereealstbfforcationproblemsm***etimepassingthrought...

关键词： stability on finite time interval time-dependent bifurcation Duffing’s equa-tion

Nonlinear flutter analysis of stiffened composite panels in super-sonic flow

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Science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 336-344页

作者： YUAN KaiHua & QIU ZhiPing school of Aeronautic Science and Engineering,Beijing university of {2. and astronautics,Beijing 100191,china 1. school of Aeronautic Science and Engineering Beijing University of Aeronautics and Astronautics Beijing 100191 China

The flutter instability of stiffened composite panels subjected to aerodynamic forces in the supersonic flow is investigated. Based on Hamilton's principle,the aeroelastic model of the composite panel is established by using the von Karman large deflection plate theory,piston theory aerodynamics and the quasi-steady thermal stress theory. Then,using the finite element method along with Bogner-Fox-Schmit elements and three-dimensional beam elements,the nonlinear equations of motion are derived. The effect of stiffening scheme on the flutter critical dynamic pressure is demonstrated through the numerical example,and the nonlinear flutter characteristics of stiffened composite panels are also analyzed in the time domain. This will lay the foundation for design of panel structures employed in aerospace vehicles.

关键词： panel flutter piston theory finite element method quasi-steady thermal stress critical dynamic pressure stiffened composite panel

CONSTRAINTS ON THE CRACK TIP PLASTIC FIELDS UNDER LARGE SCALE YIELD

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Acta Mechanica Solida Sinica 2001年第2期14卷 138-146页

作者： Xu Fei~1 Guo Wanlin~(1,2. (1 State Key Laboratory of Mechanical Structure Strength and Vibration, Xi’an Jiaotong university, Xi’an 710049, china) (2.{2. of aeronautics and astronautics,Nanjing university of aeronautics and astronautics, Nanjing 2.0016, china) State Key Laboratory of Mechanical Structure Strength and Vibration Xl'an Jiaotong University，Xi'an 710049，China State Key Laboratory of Mechanical Structure Strength and Vibration Xl'an Jiaotong University，Xi'an 710049，China school of aeronautics and {2. Nanfing University of Aeronautics and Astronautics，Nanjing 210016，China

Plane strain elastic-plastic finite element analyses are used tostudy the stress, strain fields around a straight crack in powerhardening plastic material. Center crack panel (CCP), single edgecrack panel (SECP) and double edge crack panel (DECP) tensionspecimens are analyzed with various crack lengths. Two localconstraint parameters, i.e. in-plane stress ratio T_x andout-of-plane constraint T_z are an- alyzed, which are defined astangential stress dividing normal (open) stress and out-of-planestress dividing the sum of tangential stress and normal stressrespectively.

关键词： constraint in-plane stress ratio out-of-plane constraint

Global 4-D trajectory optimization for spacecraft

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Science china(Technological Sciences) 2010年第8期53卷 2097-2101页

作者： NAN Ying ,HUANG GuoQiang,LU YuPing&GONG Ping school of astronautics,Nanjing {2. of aeronautics and astronautics,Nanjing 2.0016,china 1. school of astronautics Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Global 4-D trajectory(x,y,z,t)is optimized for a spacecraft,which is launched from the Earth to fly around the Sun,just as star-drift of 1437 asteroids in the solar *** spacecraft trajectory is controlled by low *** performance index of optimal trajectory is to maximize the rendezvous times with the intermediate asteroids,and also maximize the final *** paper provides a combined algorithm of global 4-D trajectory *** algorithm is composed of dynamic programming and two-point-boundary algorithm based on optimal control *** best 4-D trajectory is obtained:the spacecraft flies passing 55 asteroids,and rendezvous with(following or passing again)asteroids for 454 days,and finally rendezvous with the asteroid 2.05SN2. on the day 6052.(MJD),the final mass of the spacecraft is 836.53 kg.

关键词： spacecraft 4-D trajectory global optimization flight numerical simulation