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Nonlinear free vibration of spinning cylindrical shells with arbitrary boundary conditions

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Applied Mathematics and Mechanics(English Edition) 2022年第8期43卷 1203-1218页

作者： Qingdong CHAI yanqing wang Meiwen TENG Key Laboratory of Structural Dynamics of Liaoning Province College of SciencesNortheastern UniversityShenyang110819China Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines Northeastern UniversityShenyang110819China

The aim of the present study is to investigate the nonlinear free vibration of spinning cylindrical shells under spinning and arbitrary boundary *** springs are used to simulate arbitrary boundary ***’shell theory is employed,and von Kármán nonlinear terms are considered in the theoretical *** using Chebyshev polynomials as admissible functions,motion equations are derived with the Ritz ***,a direct iteration method is used to obtain the nonlinear vibration *** effects of the circumferential wave number,the boundary spring stiffness,and the spinning speed on the nonlinear vibration characteristics of the shells are *** is found that there exist sensitive intervals for the boundary spring stiffness,which makes the variation of the nonlinear frequency ratio more *** decline of the frequency ratio caused by the spinning speed is more significant for the higher vibration amplitude and the smaller boundary spring stiffness.

关键词： spinning cylindrical shell nonlinear free vibration arbitrary boundary condition Chebyshev polynomial Sanders’shell theory

Fuzzy norm method for evaluating random vibration of airborne platform from limited PSD data

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Chinese Journal of Aeronautics 2014年第6期27卷 1442-1450页

作者： wang Zhongyu wang yanqing wang Qian Zhang Jianjun School of Instrumentation Science & Opto-electronics Engineering Beihang University College of Electronic Communication and Physics Shandong University of Science and Technology Center of Quality Engineering of China Aero-Polytechnology Establishment

For random vibration of airborne platform, the accurate evaluation is a key indicator to ensure normal operation of airborne equipment in flight. However, only limited power spectral density（PSD） data can be obtained at the stage of flight test. Thus, those conventional evaluation methods cannot be employed when the distribution characteristics and priori information are unknown. In this paper, the fuzzy norm method（FNM） is proposed which combines the advantages of fuzzy theory and norm theory. The proposed method can deeply dig system information from limited data, which probability distribution is not taken into account. Firstly, the FNM is employed to evaluate variable interval and expanded uncertainty from limited PSD data, and the performance of FNM is demonstrated by confidence level, reliability and computing accuracy of expanded uncertainty. In addition, the optimal fuzzy parameters are discussed to meet the requirements of aviation standards and metrological practice. Finally, computer simulation is used to prove the adaptability of FNM. Compared with statistical methods, FNM has superiority for evaluating expanded uncertainty from limited data. The results show that the reliability of calculation and evaluation is superior to 95%.

关键词： Expanded uncertainty Fuzzy norm method Limited PSD data Random vibration Reliability Variable interval

An efficient method for vibration and stability analysis of rectangular plates axially moving in fluid

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Applied Mathematics and Mechanics(English Edition) 2021年第2期42卷 291-308页

作者： yanqing wang Han WU Fengliu YANG Quan wang Department of Mechanics College of SciencesNortheastern UniversityShenyang 110819China Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines Northeastern UniversityShenyang 110819China Department of Civil and Environmental Engineering Shantou UniversityShantou 515063Guangdong ProvinceChina

An efficient method is developed to investigate the vibration and stability of moving plates immersed in fluid by applying the Kirchhoff plate theory and finite element *** fluid is considered as an ideal fluid and is described with Bernoulli’s equation and the linear potential flow ***’s principle is used to acquire the dynamic equations of the immersed moving *** mass matrix,stiffness matrix,and gyroscopic inertia matrix are determined by the exact analytical *** numerical results show that the fundamental natural frequency of the submersed moving plates gradually decreases to zero with an increase in the axial speed,and consequently,the coupling phenomenon occurs between the first-and second-order *** is also found that the natural frequency of the submersed moving plates reduces with an increase in the fluid density or the immersion ***,the natural frequency will drop obviously if the plate is located near the rigid *** addition,the developed method has been verified in comparison with available results for special cases.

关键词： moving plate fluid-structure interaction finite element vibration stability gyroscopic dynamic system

Analytical analysis for vibration of longitudinally moving plate submerged in infinite liquid domain

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Applied Mathematics and Mechanics(English Edition) 2017年第5期38卷 625-646页

作者： yanqing wang J.W.ZU Department of Mechanics Northeastern University Department of Mechanical and Industrial Engineering University of Toronto

The vibration of a longitudinally moving rectangular plate submersed in an infinite liquid domain is studied analytically with the Rayleigh-Ritz method. The liquid is assumed to be incompressible, inviscid, and irrotational, and the velocity potential is used to describe the fluid velocity in the whole liquid field. The classical thin plate theory is used to derive mechanical energies of the traveling plate. As derivative of transverse displacement with respect to time in the compatibility condition equation exists, an exponential function is introduced to depict the dynamic deformation of the moving plate. It is shown that this exponential function works well with the Rayleigh- Ritz method. A convergence study shows a quick convergence speed for the immersed moving plate. Furthermore, the parametric study is carried out to demonstrate the effect of system parameters including the moving speed, the plate location, the liquid depth, the plate-liquid ratio, and the boundary condition. Results show that the above system parameters have significant influence on the vibration characteristics of the immersed moving plate. To extend the study, the method of added virtual mass incremental （AVMI） factor is used. The results show good agreement with those from the Rayleigh-Ritz method.

关键词： longitudinally moving plate fluid-structure interaction Rayleigh-Ritz method free vibration added virtual mass incremental (AVMI) factor method

Limit theorems for a supercritical branching process with immigration in a random environment

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Science China Mathematics 2017年第12期60卷 2481-2502页

作者： wang yanqing LIU QuanSheng School of Statistics and Mathematics Zhongnan University of Economics and Law Wuhan 430073 China Laboratoire de Mathematiques de Bretagne-Atlantique Universitd de Bretagne-Sud Vannes F-56017 France

Let(Z_n) be a supercritical branching process with immigration in a random environment. Firstly, we prove that under a simple log moment condition on the offspring and immigration distributions, the naturally normalized population size W_n converges almost surely to a finite random variable W. Secondly, we show criterions for the non-degeneracy and for the existence of moments of the limit random variable W. Finally, we establish a central limit theorem, a large deviation principle and a moderate deviation principle about log Z_n.

关键词： branching process with immigration random environment almost sure convergence nondegeneration Lpconvergence and moments large and moderate deviations central limit theorem

Nonlinear oscillations of sigmoid functionally graded material plates moving in longitudinal direction

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Applied Mathematics and Mechanics(English Edition) 2017年第11期38卷 1533-1550页

作者： yanqing wang J.W.ZU Department of Mechanics Northeastern University Department of Mechanical and Industrial Engineering University of Toronto

Geometrically nonlinear oscillations are investigated on sigmoid functionally graded material （S-FGM） plates with a longitudinal speed. The material properties of the plates obey a sigmoid distribution rule along the thickness direction. Based on the D＇Alembert＇s principle, a nonlinear equation of motion is derived for the moving S-FGM plates, where the von K^rm^n nonlinear plate theory is adopted. Utilizing the Galerkin method, the equation of motion is discretized and solved via the method of harmonic bal- ance. The approximate analytical solutions are validated through the adaptive step-size fourth-order Runge-Kutta method. Besides, the stability of the steady-state solutions is examined. The results reveal that the mode interaction behavior can happen between the first two modes of the moving S-FGM plates, leading to a complex nonlinear frequency response. It is further found that the power-law index, the longitudinal speed, the exci- tation amplitude, and the in-plane pretension force can significantly affect the nonlinear frequency-response characteristics of longitudinally traveling S-FGM plates.

关键词： sigmoid functionally graded material (S-FGM) plate moving nonlinearoscillation method of harmonic balance frequency response

Nonlinear dynamic behavior of inhomogeneous functional plates composed of sigmoid graded metal-ceramic materials

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Science China(Technological Sciences) 2018年第11期61卷 1654-1665页

作者： wang yanqing ZU Jean W. Department of Mechanics Northeastern University Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines Northeastern University Department of Mechanical and Industrial Engineering University of Toronto

This paper presents a study on nonlinear vibration of inhomogeneous functional plates composed of sigmoid graded metalceramic materials. The material properties vary continuously along the thickness direction according to a sigmoid distribution rule, which is defined by piecewise functions to ensure smooth distribution of stress among all the interfaces. The geometric nonlinearity is considered by adopting the von Kármán geometrical relations. Based on the d'Alembert's principle, the nonlinear out-of-plane equation of motion of the plates is developed. The Galerkin method is employed to discretize the motion equation to a series of ordinary differential ones, which are subsequently analyzed via the use of the method of harmonic balance. Then, the analytical results are validated by the comparison to numerical solutions, which are obtained by using the adaptive step-size fourth-order Runge-Kutta method. The stability of the steady-state response is examined by the perturbation technique. Results show the first and third modes are both activated while the second mode is not activated for the plates under harmonic point excitation. The frequency response relationships of activated modes exhibit very complicated curves due to the nonlinear modal interaction. In addition, influences of key system parameters on nonlinear vibrational characteristics of the present inhomogeneous plates are illustrated.

关键词： inhomogeneous functional plates sigmoid graded metal-ceramic material nonlinear vibration response harmonic balance method

A Two-Stage Evolutionary Game Model for Collaborative Emergency Management Between Local Governments and Enterprises

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International Journal of Disaster Risk Science 2023年第6期14卷 1029-1043页

作者： yanqing wang Hong Chen Xiao Gu School of Economics and Management China University of Mining and TechnologyXuzhou 221116China School of Business Jiangnan UniversityWuxi 214122China Research Institute of National Security and Green Development Jiangnan UniversityWuxi 214122China

Enterprises play a vital role in emergency management,but few studies have considered the strategy choices behind such participation or the collaborative relationship with the *** study contended that enterprises have at least three strategies regarding emergency management:non-participation,short-term participation,and long-term *** constructed a two-stage evolutionary game model to explore the behavioral evolution rules and evolutionary stability strategies of the government and enterprises,and employed numerical simulation to analyze how various factors influence the strategy selection of the government and *** results show that if and only if the utility value of participation is greater than 0,an enterprise will participate in emergency *** evolutionary game then enters the second stage,during which system stability is affected by a synergistic relationship between participation cost,reputation benefit,and government subsidies,and by an incremental relationship between emergency management benefit,government subsidies,and emergency training *** study provides a new theoretical perspective for research on collaborative emergency management,and the results provide important references for promoting the performance of collaborative emergency management.

关键词： Collaborative relationship Emergency management Enterprise participation Numerical simulation Two-stage evolutionary game

Identifying the temperature effect on the vibrations of functionally graded cylindrical shells with porosities

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Applied Mathematics and Mechanics(English Edition) 2018年第11期39卷 1587-1604页

作者： yanqing wang Chao YE J.W.ZU Department of Mechanics Northeastern University Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines Northeastern University Schaefer School of Engineering and Science Stevens Institute of Technology

The free thermal vibration of functionally graded material(FGM) cylindrical shells containing porosities is investigated. Both even distribution and uneven distribution are taken into account. In addition, three thermal load types, i.e., uniform temperature rise(UTR), nonlinear temperature rise(NLTR), and linear temperature rise(LTR), are researched to explore their effects on the vibration characteristics of porous FGM cylindrical shells. A modified power-law formulation is used to describe the material properties of FGM shells in the thickness direction. Love’s shell theory is used to formulate the straindisplacement equations, and the Rayleigh-Ritz method is utilized to calculate the natural frequencies of the system. The results show that the natural frequencies are affected by the porosity volume fraction, constituent volume fraction, and thermal load. Moreover,the natural frequencies obtained from the LTR have insignificant differences compared with those from the NLTR. Due to the calculation complexity of the NLTR, we propose that it is reasonable to replace it by its linear counterpart for the analysis of thin porous FGM cylindrical shells. The present results are verified in comparison with the published ones in the literature.

关键词： functionally graded material(FGM) cylindrical shell porosity free vibration thermal load Rayleigh-Ritz method