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Random vibration analysis of FGM plates subjected to moving load using a refined stochastic finite element method
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作者 Ngoc-Tu Do Trung Thanh Tran 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第4期42-56,共15页
The article introduces a finite element procedure using the bilinear quadrilateral element or four-node rectangular element(namely Q4 element) based on a refined first-order shear deformation theory(rFSDT) and Monte C... The article introduces a finite element procedure using the bilinear quadrilateral element or four-node rectangular element(namely Q4 element) based on a refined first-order shear deformation theory(rFSDT) and Monte Carlo simulation(MCS), so-called refined stochastic finite element method to investigate the random vibration of functionally graded material(FGM) plates subjected to the moving load.The advantage of the proposed method is to use r-FSDT to improve the accuracy of classical FSDT, satisfy the stress-free condition at the plate boundaries, and combine with MCS to analyze the vibration of the FGM plate when the parameter inputs are random quantities following a normal distribution. The obtained results show that the distribution characteristics of the vibration response of the FGM plate depend on the standard deviation of the input parameters and the velocity of the moving load.Furthermore, the numerical results in this study are expected to contribute to improving the understanding of FGM plates subjected to moving loads with uncertain input parameters. 展开更多
关键词 FGM Moving load R-FSDT Q4 element Monte Carlo simulation random vibration
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Random vortex induced vibration response of suspended flexible cable to fluctuating wind
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作者 Genjin MU Weiqiu ZHU Maolin DENG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第12期2207-2226,共20页
A popular dynamical model for the vortex induced vibration(VIV)of a suspended flexible cable consists of two coupled equations.The first equation is a partial differential equation governing the cable vibration.The se... A popular dynamical model for the vortex induced vibration(VIV)of a suspended flexible cable consists of two coupled equations.The first equation is a partial differential equation governing the cable vibration.The second equation is a wake oscillator that models the lift coefficient acting on the cable.The incoming wind acting on the cable is usually assumed as the uniform wind with a constant velocity,which makes the VIV model be a deterministic one.In the real world,however,the wind velocity is randomly fluctuant and makes the VIV of a suspended flexible cable be treated as a random vibration.In the present paper,the deterministic VIV model of a suspended flexible cable is modified to a random one by introducing the fluctuating wind.Using the normal mode approach,the random VIV system is transformed into an infinite-dimensional modal vibration system.Depending on whether a modal frequency is close to the aeolian frequency or not,the corresponding modal vibration is characterized as a resonant vibration or a non-resonant vibration.By applying the stochastic averaging method of quasi Hamiltonian systems,the response of modal vibrations in the case of resonance or non-resonance can be analytically predicted.Then,the random VIV response of the whole cable can be approximately calculated by superimposing the response of the most influential modal vibrations.Some numerical simulation results confirm the obtained analytical results.It is found that the intensity of the resonant modal vibration is much higher than that of the non-resonant modal vibration.Thus,the analytical results of the resonant modal vibration can be used as a rough estimation for the whole response of a cable. 展开更多
关键词 vortex induced vibration(VIV) wake oscillator random response suspended flexible cable fluctuating wind
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Random vibration of hysteretic systems under Poisson white noise excitations
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作者 Lincong CHEN Zi YUAN +1 位作者 Jiamin QIAN J.Q.SUN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第2期207-220,共14页
Hysteresis widely exists in civil structures,and dissipates the mechanical energy of systems.Research on the random vibration of hysteretic systems,however,is still insufficient,particularly when the excitation is non... Hysteresis widely exists in civil structures,and dissipates the mechanical energy of systems.Research on the random vibration of hysteretic systems,however,is still insufficient,particularly when the excitation is non-Gaussian.In this paper,the radial basis function(RBF)neural network(RBF-NN)method is adopted as a numerical method to investigate the random vibration of the Bouc-Wen hysteretic system under the Poisson white noise excitations.The solution to the reduced generalized Fokker-PlanckKolmogorov(GFPK)equation is expressed in terms of the RBF-NNs with the Gaussian activation functions,whose weights are determined by minimizing the loss function of the reduced GFPK equation residual and constraint associated with the normalization condition.A steel fiber reinforced ceramsite concrete(SFRCC)column loaded by the Poisson white noise is studied as an example to illustrate the solution process.The effects of several important parameters of both the system and the excitation on the stochastic response are evaluated,and the obtained results are compared with those obtained by the Monte Carlo simulations(MCSs).The numerical results show that the RBF-NN method can accurately predict the stationary response with a considerable high computational efficiency. 展开更多
关键词 random vibration Bouc-Wen hysteresis system non-Gaussian excitation Poisson white noise excitation radial basis function(RBF)neural network(RBF-NN)
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Adaptive inverse control of random vibration based on the filtered-X LMS algorithm 被引量:10
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作者 Yang Zhidong,Huang Qitao~(++),Han Junwei~§and Li Hongren~§National Key Laboratory of Robots Technique and System,Harbin Institute of Technology,Harbin 150080,China PhD Candidate ~++ PhD ~§Professor 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2010年第1期141-146,共6页
Random vibration control is aimed at reproducing the power spectral density (PSD) at specified control points. The classical frequency-spectrum equalization algorithm needs to compute the average of the multiple fre... Random vibration control is aimed at reproducing the power spectral density (PSD) at specified control points. The classical frequency-spectrum equalization algorithm needs to compute the average of the multiple frequency response functions (FRFs), which lengthens the control loop time in the equalization process. Likewise, the feedback control algorithm has a very slow convergence rate due to the small value of the feedback gain parameter to ensure stability of the system. To overcome these limitations, an adaptive inverse control of random vibrations based on the filtered-X least mean-square (LMS) algorithm is proposed. Furthermore, according to the description and iteration characteristics of random vibration tests in the frequency domain, the frequency domain LMS algorithm is adopted to refine the inverse characteristics of the FRF instead of the traditional time domain LMS algorithm. This inverse characteristic, which is called the impedance function of the system under control, is used to update the drive PSD directly. The test results indicated that in addition to successfully avoiding the instability problem that occurs during the iteration process, the adaptive control strategy minimizes the amount of time needed to obtain a short control loop and achieve equalization. 展开更多
关键词 random vibration power spectral density frequency response function adaptive inverse control filtered-X LMS algorithm
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Parametric Vibration of Submerged Floating Tunnel Tether Under Random Excitation 被引量:6
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作者 孙胜男 苏志彬 《China Ocean Engineering》 SCIE EI 2011年第2期349-356,共8页
For the study of the parametric vibration response of submerged floating tunnel tether under random excitation, a nonlinear random parametric vibration equation of coupled tether and tube of submerged floating tunnel ... For the study of the parametric vibration response of submerged floating tunnel tether under random excitation, a nonlinear random parametric vibration equation of coupled tether and tube of submerged floating tunnel is set up. Subsequently, vibration response of tether in the tether-tube system is analyzed by Monte Carlo method. It may be concluded that when the tube is subjected to zero-mean Gaussian white noise random excitation, the displacement and velocity root mean square responses of tether reach the peak if the circular frequency of tube doubles that of tether; the displacement and velocity root mean square responses of tether increase as the random excitation root mean square increases; owing to the damping force of water, the displacement and velocity root mean square responses of tether decrease rapidly compared with tether in air; increasing the damping of the tether or tube reduces the displacement and velocity root mean square responses of tether; the large-amplitude vibration of tether may be avoided by locating dampers on the tether or tube. 展开更多
关键词 ocean engineering submerged floating tunnel TETHER parametric vibration random excitation
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Random Vibration Analysis of the Electronic Equipment Cabinet 被引量:3
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作者 LIU Yanping~1 LIU Dongqing~2 1.Key Laboratory of Condition Monitoring and Control for Power Plant Equipment of Ministry of Education,North China Electric Power University,Beijing 102206 ,China 2.Beijing University of Science and Technology,Beijing 100083,China 《武汉理工大学学报》 CAS CSCD 北大核心 2006年第S2期709-713,共5页
In order to understand the vibration characteristic of system structure of electronic equipment cabinet within the particular vibration frequency,the finite element analysis software-ANSYS is used to simulate the test... In order to understand the vibration characteristic of system structure of electronic equipment cabinet within the particular vibration frequency,the finite element analysis software-ANSYS is used to simulate the tests of random vibrations of the cabinet system and obtain the isopleths graph of deformation and stress of the cabinet.It can confirm maximum of deformation and stress of the cabinet and position happened.Through more analysis of the frequency response curve,which can confirm harm- ful consequences random vibrations caused and weak link of the cabinet structure.The numerical simulation results are in good a- greement with the experimental results.It shows that this research provides an efficient method for the anti-seismic design and the dynamic optimization design. 展开更多
关键词 random vibrations test vibration CHARACTERISTIC NUMERICAL simulation FINITE ELEMENT analysis electronic equipment CABINET ANSYS software
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Improvement for design of beam structures in large vibrating screen considering bending and random vibration 被引量:6
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作者 彭利平 刘初升 +2 位作者 宋宝成 武继达 王帅 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第9期3380-3388,共9页
Demand for large vibrating screen is huge in the mineral processing industry. As bending and random vibration are not considered in a traditional design method for beam structures of a large vibrating screen, fatigue ... Demand for large vibrating screen is huge in the mineral processing industry. As bending and random vibration are not considered in a traditional design method for beam structures of a large vibrating screen, fatigue damage occurs frequently to affect the screening performance. This work aims to conduct a systematic mechanics analysis of the beam structures and improve the design method. Total motion of a beam structure in screening process can be decomposed into the traditional followed rigid translation(FRT), bending vibration(BV) and axial linear-distributed random rigid translation(ALRRT) excited by the side-plates. When treated as a generalized single-degree-of-freedom(SDOF) elastic system analytically, the BV can be solved by the Rayleigh's method. Stochastic analysis for random process is conducted for the detailed ALRRT calculation. Expressions for the mechanics property, namely, the shearing force and bending-moment with respect to BV and ALRRT, are derived, respectively. Experimental and numerical investigations demonstrate that the largest BV exists at the beam center and can be nearly ignored in comparison with the FRT during a simplified engineering design. With the BV and FRT considered, the mechanics property accords well with the practical situation with the maximum error of 6.33%, which is less than that obtained by traditional method. 展开更多
关键词 large vibrating screen BEAM bending vibration random vibration mechanics analysis
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Novel method for random vibration analysis of single-degree-of-freedom vibroimpact systems with bilateral barriers 被引量:2
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作者 Lincong CHEN Haisheng ZHU J.Q.SUN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2019年第12期1759-1776,共18页
The vibroimpact systems with bilateral barriers are often encountered in practice.However,the dynamics of the vibroimpact system with bilateral barriers is full of challenges.Few closed-form solutions were obtained.In... The vibroimpact systems with bilateral barriers are often encountered in practice.However,the dynamics of the vibroimpact system with bilateral barriers is full of challenges.Few closed-form solutions were obtained.In this paper,we propose a novel method for random vibration analysis of single-degree-of-freedom(SDOF)vibroim-pact systems with bilateral barriers under Gaussian white noise excitations.A periodic approximate transformation is employed to convert the equations of the motion to a con-tinuous form.The probabilistic description of the system is subsequently defined through the corresponding Fokker-Planck-Kolmogorov(FPK)equation.The closed-form station-ary probability density function(PDF)of the response is obtained by solving the reduced FPK equation and using the proposed iterative method of weighted residue together with the concepts of the circulatory probability flow and the potential probability flow.Finally,the versatility of the proposed approach is demonstrated by its application to two typical examples.Note that the solution obtained by using the proposed method can be used as the benchmark to examine the accuracy of approximate solutions obtained by other methods. 展开更多
关键词 BILATERAL BARRIER vibroimpact system weighted RESIDUE method ITERATIVE random vibration
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Random vibration analysis of switching apparatus based on Monte Carlo method 被引量:6
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作者 ZHAI Guo-fu CHEN Yang-hua REN Wan-bin 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第3期422-425,共4页
The performance in vibration environment of switching apparatus containing mechanical contact is an important element when judging the apparatus’s reliability. A piecewise linear two-degrees-of-freedom mathematical m... The performance in vibration environment of switching apparatus containing mechanical contact is an important element when judging the apparatus’s reliability. A piecewise linear two-degrees-of-freedom mathematical model considering contact loss was built in this work, and the vibration performance of the model under random external Gaussian white noise excitation was investigated by using Monte Carlo simulation in Matlab/Simulink. Simulation showed that the spectral content and statistical characters of the contact force coincided strongly with reality. The random vibration character of the contact system was solved using time (numerical) domain simulation in this paper. Conclusions reached here are of great importance for reliability design of switching apparatus. 展开更多
关键词 Contact system random vibration Monte Carlo simulation MATLAB/SIMULINK
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Vibration and acoustic radiation of bogie area under random excitation in high-speed trains 被引量:3
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作者 Dongzhen Wang Jianmin Ge 《Journal of Modern Transportation》 2019年第2期120-128,共9页
Based on the experiments on a platform with real vehicle structure and finite element simulation, the vibration and interior acoustic radiation under random excitations of high-speed trains’ bogie area were studied. ... Based on the experiments on a platform with real vehicle structure and finite element simulation, the vibration and interior acoustic radiation under random excitations of high-speed trains’ bogie area were studied. Firstly, combined with line tests, a vehicle body with a length of 7 m was used as the research object. By comparing the results of experiment and simulation, the accuracy of the finite element model was verified. Secondly, the power spectral density curves at typical measuring points in bogie area were obtained by processing and calculating the line test data, which was measured when the vehicle ran at high speeds, and the standard vibration spectrum of the bogie area was obtained by the extreme envelope method. Furthermore, the random vibration test and simulation prediction analysis of the real vehicle structure were carried out to further verify the accuracy of the noise and vibration prediction model. Finally, according to the vibration and acoustic radiation theory, the indirect boundary element method was adopted to predict the acoustic response of the real vehicle. The analysis shows that the simulated power spectral density curves of acceleration and sound pressure level are highly consistent with the experimental ones, and the error between the simulated prediction and the experimental result is within the allowable range of 3 dB. 展开更多
关键词 High-speed TRAINS Standard vibration SPECTRUM Indirect BOUNDARY element method random EXCITATION Acoustic radiation
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Stochastic resonance whole body vibration reduces musculoskeletal pain:A randomized controlled trial 被引量:4
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作者 Achim Elfering Jan Thomann +1 位作者 Volker Schade Lorenz Radlinger 《World Journal of Orthopedics》 2011年第12期116-120,共5页
AIM:To examined the effects of stochastic resonance whole-body vibration training on musculoskeletal pain in young healthy individuals.METHODS:Participants were 43 undergraduate students of a Swiss University.The stud... AIM:To examined the effects of stochastic resonance whole-body vibration training on musculoskeletal pain in young healthy individuals.METHODS:Participants were 43 undergraduate students of a Swiss University.The study was designed as a randomized controlled trial(RCT)with randomized group allocation.The RCT consisted of two groups each given 12 training sessions during four weeks with either 5 Hz-Training frequency(training condition)or 1.5 Hz Training frequency(control condition).Outcome was current musculoskeletal pain assessed in the evening on each day during the four week training period.RESULTS:Multilevel regression analysis showed musculoskeletal pain was significantly decreased in the training condition whereas there was no change in the control condition(B=-0.023,SE=0.010,P=0.021).Decrease in current musculoskeletal pain over four weeks was linear.CONCLUSION:Stochastic resonance whole-body vibration reduced musculoskeletal pain in young healthy individuals.Stochastic resonance vibration and not any other exercise component within training caused pain reduction. 展开更多
关键词 randomIZED controlled TRIAL MUSCULOSKELETAL PAIN Training study STOCHASTIC vibration
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SEISMIC RANDOM VIBRATION ANALYSIS OF LOCALLY NONLINEAR STRUCTURES 被引量:1
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作者 ZhaoYan LinJiahao +1 位作者 ZhangYahui AnWei 《Acta Mechanica Solida Sinica》 SCIE EI 2003年第3期240-244,共5页
A nonlinear seismic analysis method for complex frame structures subjected to sta- tionary random ground excitations is proposed.The nonlinear elasto-plastic behaviors may take place only on a small part of the struct... A nonlinear seismic analysis method for complex frame structures subjected to sta- tionary random ground excitations is proposed.The nonlinear elasto-plastic behaviors may take place only on a small part of the structure.The Bouc-Wen differential equation model is used to model the hysteretic characteristics of the nonlinear components.The Pseudo Excitation Method (PEM)is used in solving the linearized random differential equations to replace the solution of the less efficient Lyapunov equation.Numerical results of a real bridge show that the method proposed is effective for practical engineering analysis. 展开更多
关键词 hysteretic system random vibration power spectral pseudo excitation method statistic linearization
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Performance improvement of the stochastic-resonance-based tri-stableenergy harvester under random rotational vibration 被引量:2
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作者 Tingting Zhang Yanfei Jin Yanxia Zhang 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2022年第5期326-331,共6页
In this paper,the stochastic-resonance-based tri-stable energy harvester(TEH)is proposed to enhance harvesting performance under random rotational vibration.An electromechanical coupled system interfaced with a standa... In this paper,the stochastic-resonance-based tri-stable energy harvester(TEH)is proposed to enhance harvesting performance under random rotational vibration.An electromechanical coupled system interfaced with a standard rectifier circuit driven by colored noise is considered.The stationary probability density function(SPDF)of the harvester is obtained by the improved stochastic averaging.Then,with the adiabatic approximation theory,the analytical expression of signal-to-noise ratio(SNR)for the TEH is deduced to characterize stochastic resonance(SR).To enhance direct current(DC)power delivery from a rotational TEH,the influences of system parameters on SR is discussed.The obtained results suggest that there are damping-induced resonance and noise-intensity-induced SR in the tri-stable system.The TEH has higher harvesting performance under the optimal SR.That is,the optimal parameter combinations can induce optimal SR and maximize harvesting performance.Thus,the stochastic-resonance-based TEH can be optimized to enhance energy harvesting through choosing the optimal parameter. 展开更多
关键词 Tri-stable energy harvesting Stochastic resonance random rotational vibration Signal-to-noise ratio
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Response of train-bridge system under intensive seismic excitation by random vibration method 被引量:2
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作者 WU Zhao-zhi ZHANG Nan 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第8期2467-2484,共18页
Earthquake is a kind of sudden and destructive random excitation in nature.It is significant to determine the probability distribution characteristics of the corresponding dynamic indicators to ensure the safety and t... Earthquake is a kind of sudden and destructive random excitation in nature.It is significant to determine the probability distribution characteristics of the corresponding dynamic indicators to ensure the safety and the stability of structures when the intensive seismic excitation,the intensity of which is larger than 7,acts in train-bridge system.Firstly,the motion equations of a two-dimensional train-bridge system under the vertical random excitation of track irregularity and the vertical seismic acceleration are established,where the train subsystem is composed of 8 mutually independent vehicle elements with 48 degrees of freedom,while the single-span simple supported bridge subsystem is composed of 102D beam elements with 20 degrees of freedom on beam and 2 large mass degrees of freedom at the support.Secondly,Monte Carlo method and pseudo excitation method are adopted to analyze the statistical parameters of the system.The power spectrum density of random excitation is used to define a series of non-stationary pseudo excitation in pseudo excitation method and the trigonometric series of random vibration history samples in Monte Carlo method,respectively solved by precise integral method and Newmark-βmethod through the inter-system iterative procedure.Finally,the results are compared with the case under the weak seismic excitation,and show that the samples of vertical acceleration response of bridge and the offload factor of train obeys the normal distribution.In a high probability,the intensive earthquakes pose a greater threat to the safety and stability of bridges and trains than the weak ones. 展开更多
关键词 random vibration method intensive seismic excitation train-bridge system probability distribution inter system iteration precise integral method
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SEISMIC RANDOM VIBRATION ANALYSIS OF STOCHASTIC STRUCTURES USING RANDOM FACTOR METHOD 被引量:2
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作者 KESSISSOGLOU Nicole J 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2006年第1期1-8,共8页
Seismic random vibration analysis of stochastic truss structures is presented. A new method called random factor method is used for dynamic analysis of structures with uncertain parameters, due to variability in their... Seismic random vibration analysis of stochastic truss structures is presented. A new method called random factor method is used for dynamic analysis of structures with uncertain parameters, due to variability in their material properties and geometry. Using the random factor method, the natural frequencies and modeshapes of a stochastic structure can be respectively described by the product of two parts, corresponding to the random factors of the structural parameters with uncertainty, and deterministic values of the natural frequencies and modeshapes obtained by conventional finite element analysis. The stochastic truss structure is subjected to stationary or non-stationary random earthquake excitation. Computational expressions for the mean and standard deviation of the mean square displacement and mean square stress are developed by means of the random variable's functional moment method and the algebra synthesis method. An antenna and a truss bridge are used as practical engineering examples to illustrate the application of the random factor method in the seismic response analysis of random structures under stationary or non-stationary random earthquake excitation. 展开更多
关键词 Seismic random vibration Uncertainty structures random factor methodNon-stationary ground motion
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Random Vibration Analysis of Urban Underground Tunnels Under Vertical Earthquake Excitations Based on Mass–Damper–Spring Model 被引量:1
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作者 Haitao Zhu Tianjiao Tang +1 位作者 Puyang Zhang Jianqiao Sun 《Transactions of Tianjin University》 EI CAS 2018年第3期290-300,共11页
In this paper, the verticalseismic effects on tunnels are studied based on a classic mass–damper–spring model. An analyticaldiscrete modelof urban underground tunnels subjected to verticalearthquake excitations is p... In this paper, the verticalseismic effects on tunnels are studied based on a classic mass–damper–spring model. An analyticaldiscrete modelof urban underground tunnels subjected to verticalearthquake excitations is proposed by considering the first verticalvibration mode. Taking a light railproject in Tianjin as an example, this study uses the proposed discrete modelto analyze the displacements of tunneland soilunder verticalearthquake excitations. The soildisplacement responses at different tunnellocations are analyzed with linear random vibration theory.The computationalcost is greatly reduced using the proposed model. It can be seen that different from the case of horizontalearthquakes, the displacement responses under verticalearthquake excitations keep growing after seismic acceleration reaches its peak for a short duration, and then,they begin to decay. The soils at different positions around the tunnels have large relative displacement under verticalearthquake excitations. Moreover, a finite-element modelis also established for displacement responses using ABAQUS.The comparison with the results of the finite-element modelshows that the results of the proposed discrete modelare available. 展开更多
关键词 Underground tunnel Vertical seismic action Mass-damper-spring model random vibration
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Reliability based multiobjective optimization for design of structures subject to random vibrations 被引量:1
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作者 Giuseppe Carlo MARANO 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第1期15-25,共11页
Based on a multiobjective approach whose objective function (OF) vector collects stochastic reliability performance and structural cost indices, a structural optimization criterion for mechanical systems subject to ra... Based on a multiobjective approach whose objective function (OF) vector collects stochastic reliability performance and structural cost indices, a structural optimization criterion for mechanical systems subject to random vibrations is presented for supporting engineer’s design. This criterion differs from the most commonly used conventional optimum design criterion for random vibrating structure, which is based on minimizing displacement or acceleration variance of main structure responses, without considering explicitly required performances against failure. The proposed criterion can properly take into account the design-reliability required performances, and it becomes a more efficient support for structural engineering decision making. The multiobjective optimum (MOO) design of a tuned mass damper (TMD) has been developed in a typical seismic design problem, to control structural vibration induced on a multi-storey building structure excited by nonstationary base acceleration random process. A numerical example for a three-storey building is developed and a sensitivity analysis is carried out. The results are shown in a useful manner for TMD design decision support. 展开更多
关键词 Structural optimization Multiobjective optimization (MOO) random vibration Tuned mass damper (TMD)
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Analysis on Pseudo Excitation of Random Vibration for Structure of Time Flight Counter 被引量:1
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作者 WU Qiong LI Dapeng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第2期325-330,共6页
Traditional computing method is inefficient for getting key dynamical parameters of complicated structure.Pseudo Excitation Method(PEM)is an effective method for calculation of random vibration.Due to complicated an... Traditional computing method is inefficient for getting key dynamical parameters of complicated structure.Pseudo Excitation Method(PEM)is an effective method for calculation of random vibration.Due to complicated and coupling random vibration in rocket or shuttle launching,the new staging white noise mathematical model is deduced according to the practical launch environment.This deduced model is applied for PEM to calculate the specific structure of Time of Flight Counter(ToFC).The responses of power spectral density and the relevant dynamic characteristic parameters of ToFC are obtained in terms of the flight acceptance test level.Considering stiffness of fixture structure,the random vibration experiments are conducted in three directions to compare with the revised PEM.The experimental results show the structure can bear the random vibration caused by launch without any damage and key dynamical parameters of ToFC are obtained.The revised PEM is similar with random vibration experiment in dynamical parameters and responses are proved by comparative results.The maximum error is within 9%.The reasons of errors are analyzed to improve reliability of calculation.This research provides an effective method for solutions of computing dynamical characteristic parameters of complicated structure in the process of rocket or shuttle launching. 展开更多
关键词 pseudo excitation method power spectral density random processes dynamic response vibration
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Parametric characteristic of the random vibration response of nonlinear systems 被引量:2
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作者 Xing-Jian Dong Zhi-Ke Peng +2 位作者 Wen-Ming Zhang Guang Meng Fu-Lei Chu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2013年第2期267-283,共17页
Volterra series is a powerful mathematical tool for nonlinear system analysis,and there is a wide range of nonlinear engineering systems and structures that can be represented by a Volterra series model.In the present... Volterra series is a powerful mathematical tool for nonlinear system analysis,and there is a wide range of nonlinear engineering systems and structures that can be represented by a Volterra series model.In the present study,the random vibration of nonlinear systems is investigated using Volterra series.Analytical expressions were derived for the calculation of the output power spectral density(PSD) and input-output cross-PSD for nonlinear systems subjected to Gaussian excitation.Based on these expressions,it was revealed that both the output PSD and the input-output crossPSD can be expressed as polynomial functions of the nonlinear characteristic parameters or the input intensity.Numerical studies were carried out to verify the theoretical analysis result and to demonstrate the effectiveness of the derived relationship.The results reached in this study are of significance to the analysis and design of the nonlinear engineering systems and structures which can be represented by a Volterra series model. 展开更多
关键词 Volterra series·Nonlinear system·random vibration·Power spectrum density·Generalized frequency response functions
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Random vibration of nonlinear structures with stiffness and strength deterioration by modified tail equivalent linearization method
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作者 Reza Raoufi Mohsen Ghafory-Ashtiany 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2019年第3期597-610,共14页
In this research the tail equivalent linearization method (TELM) has been extended to study structures with degrading materials. The responses of such structures to excitations are non-stationary, even if the excitati... In this research the tail equivalent linearization method (TELM) has been extended to study structures with degrading materials. The responses of such structures to excitations are non-stationary, even if the excitations are stationary. Non-stationary behavior of the system cannot be considered by conventional TELM. Applying the conventional TELM, the only distinction in the design point excitation for two stationary excitations with diff erent durations is in the addition of a zero value part at the beginning of the design point of the longer excitation. This means that the failure probability is the same for the non-stationary systems under excitations with diff erent durations. Therefore, this solution cannot be correct. In this study, in using TELM for systems with degrading materials, hysteretic energy is replaced by average hysteretic energy, calculated by averaging the obtained hysteretic energy of the structure subjected to a few random sample load realization. In this way, the degradation parameters under design point coincide with those under sample load realizations. Since the average of the hysteretic energy is converges very fast, the modifi ed TELM only requires about tens to hundreds solutions of the response in addition to the ordinary calculations of conventional TELM. 展开更多
关键词 Nonlinear LINEARIZATION random vibration DEGRADATION
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