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Journal of Hydrodynamics 2011年第2期23卷 154-163页

作者： GAO Yun ZONG Zhi SUN Lei State Key Laboratory of Structural Analysis for Industrial Equipment and Department of Naval Architecture and Faculty of Vehicle Engineering and Mechanics Dalian University of Technology Dalian 116024 China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian116024 China Faculty of Vehicle Engineering and Mechanics Dalian University of Technology Dalian 116024 China

For studying the characteristics of Steel Catenary Riser （SCR）, a simplified pinned-pinned cable model of vibration is established. The natural frequencies, the normalized mode shapes and mode curvatures of the SCR are calculated. The fatigue damage of the SCR can be obtained by applying the modal superposition method combined with the parameters of S -N curve. For analyzing the relation between the current velocity and the SCR＇s fatigue damage induced by the vortex-induced vibration, ten different current states are evaluated. Then, some useful conclusions are drawn, especially an important phenomenon is revealed that the maximum fatigue damage in the riser usually occurs near the area of the boundary ends.

关键词： vortex-induced vibration Steel Catenary Riser (SCR) fatigue damage modal superposition method

Experimental and analytical studies on the vibration serviceability of long-span prestressed concrete floor

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Earthquake Engineering and Engineering Vibration 2018年第2期17卷 417-428页

作者： Cao Liang Liu Jiepeng Li Jiang Zhang Ruizhi School of Civil Engineering Chongqing University Key Laboratory of New Technology for Construction of Cities in Mountain Area (Chongqing University) Ministry of Education

An extensive experimental and theoretical research study was undertaken to study the vibration serviceability of a long-span prestressed concrete floor system to be used in the lounge of a major ***,jumping impact tests were carried out to obtain the floor’s modal parameters,followed by an analysis of the distribution of peak *** tests were also performed to capture the acceleration *** prestressed concrete floor was found to have a low fundamental natural frequency（≈8.86 Hz）corresponding to the average modal damping ratio of≈2.17%.A coefficients plate with simply-supported *** calculated analytical results（natural frequencies and root-mean-square acceleration）agree well with the experimental *** analytical approach is thus validated.

关键词： vibration serviceability prestressed concrete floor airport lounge theoretical analysis modal superposition method

Aerodynamic and structural characteristics of helicopter rotor in circling flight

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Chinese Journal of Aeronautics 2023年第12期36卷 282-296页

作者： Xu ZHOU Xiayang ZHANG Bo WANG Qijun ZHAO National Key Laboratory of Helicopter Aeromechanics Nanjing University of Aeronautics and AstronauticsNanjing 210016China

To investigate the distinct properties of the helicopter rotors during circling flight,the aerodynamic and dynamic models for the main rotor are established considering the trim conditions and the flight parameters of *** free wake method is introduced to compute the unsteady aerodynamic loads of the rotor characterized by distortions of rotor wakes,and the modal superposition method is used to predict the overall structural loads of the *** effectiveness of the aerodynamic and the structural methods is verified by comparison with the experimental results,whereby the influences of circling direction,radius,and velocity are evaluated in both aerodynamic and dynamic *** results demonstrate that the circling condition makes a great difference to the performance of rotor vortex,as well as the unsteady aerodynamic *** the decrease of the circling radius or the increment of the circling velocity,the thrust of the main rotor increases apparently to balance the inertial ***,the harmonics of aerodynamic loads in rotor disc change severely and an evident aerodynamic load shock appears at high-order components,which further causes a shift-of-peak-phase bending moment in the flap ***,the advancing side of blade experiences second blade/vortex interaction,whose intensity has a distinct enhancement as the circling radius decreases with the motion of vortexes.

关键词： Aerodynamic load Circling state Free wake method modal superposition method Structural load

Forced transverse vibration of rolls for four-high rolling mill

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Journal of Central South University 2009年第6期16卷 954-960页

作者：孙建亮彭艳刘宏民江光彪 State Key Laboratory of Metastable Materials Science and Technology Yanshan University Engineering Research Center of Rolling Equipment and Complete Technology of Ministry of Education Yanshan University Hot Rolling Mill of Baoshan Iron and Steel Co Ltd

In order to investigate the forced transverse vibration of rolls under distributed draught pressure and moment of bending roll force, the forced transverse vibration model of rolls for four-high rolling mill was established. The work roll and backup roll were considered as elastic continuous bodies that were joined by a Winkler elastic layer. According to Euler-Bemoulli beam theory, the forced transverse vibration of rolls was analyzed based on modal superposition method. The forced vibration equations were established when the draught pressure and moment of bending roll force were imposed on the rolls respectively. Numerical modeling was made on 2 030 mm cold tandem rolling mill of Baoshan Iron and Steel Company. Simulation results show that when the work roll is only subjected to different forms of draught pressures, the vibration curves of work roll and backup roll are quadratic curves with amplitudes of 0.3 mm and 45 μm, respectively. When only the moments of bending roll force are imposed on the work roll and backup roll, the vibration curves of work roll and backup roll are quadratic curves, and the amplitudes are 5.0 and 1.6 μm, respectively. The influence of moment of bending roll force on the vibration of work roll is related with the bending roll force.

关键词： four-high mill forced transverse vibration rolls modal superposition method

Experimental Investigation and Numerical Simulation of Ship Stern Structural Vibration Model

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Journal of Shanghai Jiaotong university(Science) 2022年第3期27卷 365-374页

作者： YE Xinghong XIA Lijuan State Key Laboratory of Ocean Engineering Collaborative Innovation Center for Advanced Ship and Deep-Sea ExplorationSchool of Naval ArchitectureOcean&Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Vibration at the stern area is generally the most severe of the entire ship hull,which has always attracted special attention by ship designers and *** reference to a real ship structural layout,a scaled stern model of steel structure was innovatively designed to carry out the mode and response *** finite element(FE)model representing the tested structure was established for verification of commonly-used calculation methods of modal parameters and *** agreement between experimental and numerical results demonstrates the credibility of FE method,and some key points of modeling and calculating are *** addition,with the combination of the experiment and calculation,some vibration characteristics of ship stern structure are summarized for future ship design guideline.

关键词： stern vibration model test virtual mass method modal superposition method vibration characteristics finite element(FE)model

Efficient Procedure for Seismic Analysis of Soil-Structure Interaction System

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Tsinghua Science and Technology 2006年第6期11卷 625-631页

作者：刘晶波谷音王艳李彬 Department of Civil Engineering Tsinghua University

A simplified and efficient procedure, based on the viscous-spring artificial boundary and the modal superposition method, is developed to analyze the dynamic soil-structure interaction system in the time domain. The viscous-spring artificial boundary introduced in this procedure transforms the infinite soil-structure interaction system to an approximately finite system. A seismic wave input method is used to transform the wave scattering problem into the wave source problem. The modal superposition method is then applied to this approximate finite system. The results show that this method with only a few modes can significantly reduce the computational time with almost the same precision as the traditional direct integration method. Comparison of results from different loading times demonstrates that the advantages of this method are evident in computing with long loading time.

关键词： infinite system finite system dynamic soil-structure interaction viscous-spring artificial boundary input of seismic wave motion modal superposition method