The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Wenqian Sun - One of the best experts on this subject based on the ideXlab platform.
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Stress response of the hydraulic composite pipe subjected to Random Vibration
Composite Structures, 2021Co-Authors: Huailiang Zhang, Wenqian SunAbstract:Abstract In this paper, the stress response characteristics of the hydraulic composite pipe subjected to Random Vibrations were studied. Based on 3D-anisotropy elasticity, the motion equation of the hydraulic composite pipe was established by utilizing the Hamilton principle subjected to Random Vibration, and takes into account the fluid-structure interaction (FSI). The discrete analysis method of Random Vibration is employed to solve the Random Vibration under the excitation of white noise. Also, the effects of different parameters including external excitation, fluid velocity, fluid pressure and structural parameters on the stress response of composite pipe are investigated. Experimental results agreed with the simulation results, demonstrating that the analytical method could provide theoretical reference for the design, improved efficiency, and fatigue reduction of the composite pipe subjected to Random Vibration.
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In-plane dynamic response of a hydraulic pipe subjected to Random Vibration
Engineering Computations, 2020Co-Authors: Huailiang Zhang, Ling Peng, Wenqian SunAbstract:Purpose To improve the transmission efficiency and reduce the damage to pipes in the hydraulic systems of tunnel boring machine subjected to Random Vibration, this paper aims to propose a novel dynamic characteristic analysis method that considers Random Vibration. Design/methodology/approach A fluid-structure interaction motion equation of the pipe is established by using Hamilton’s principle. The finite element method and discrete analysis method of Random Vibration are used to construct a model of the dynamic behavior of the pipe. Findings The influences of fluid parameters and external excitation parameters on the dynamic characteristics of pipes are analyzed. The experimental results are found to be in good agreement with the simulation results, which demonstrates that the proposed analytical method can provide a theoretical reference for the design and selection of hydraulic pipes subjected to Random Vibration. Originality/value The proposed method can be regarded as a future calculation method for pipes subjected to Random Vibration, and the transmission efficiency of the pipe can be improved.
Raouf A. Ibrahim - One of the best experts on this subject based on the ideXlab platform.
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Nonlinear Random Vibration: Experimental Results
Applied Mechanics Reviews, 1991Co-Authors: Raouf A. IbrahimAbstract:Experimental investigations of Random excitation of dynamic systems are valuable but scarce. They are particularly important for nonlinear Random Vibrations, since different approaches can lead to different results for the same problem. They are also useful in providing physical insight into a number of complex dynamic phenomena and in identifying the modal parameters of systems. The scarcity of Random Vibration testing is mainly due to a number of difficulties and errors encountered in generating the correct Random excitation, and data acquisition. The purpose of this review article is to assess the recent experimental results reported in the literature by the author and others. An attempt will be made to correlate the experimental measurements qualitatively with those predicted analytically. In most cases, no quantitative comparisons have been made. Difficulties encountered in experimental tests, data acquisition, and associated errors, will be discussed. New research directions based on recent analytical and experimental developments in the theory of nonlinear Random Vibration will also be outlined.
Huailiang Zhang - One of the best experts on this subject based on the ideXlab platform.
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Stress response of the hydraulic composite pipe subjected to Random Vibration
Composite Structures, 2021Co-Authors: Huailiang Zhang, Wenqian SunAbstract:Abstract In this paper, the stress response characteristics of the hydraulic composite pipe subjected to Random Vibrations were studied. Based on 3D-anisotropy elasticity, the motion equation of the hydraulic composite pipe was established by utilizing the Hamilton principle subjected to Random Vibration, and takes into account the fluid-structure interaction (FSI). The discrete analysis method of Random Vibration is employed to solve the Random Vibration under the excitation of white noise. Also, the effects of different parameters including external excitation, fluid velocity, fluid pressure and structural parameters on the stress response of composite pipe are investigated. Experimental results agreed with the simulation results, demonstrating that the analytical method could provide theoretical reference for the design, improved efficiency, and fatigue reduction of the composite pipe subjected to Random Vibration.
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In-plane dynamic response of a hydraulic pipe subjected to Random Vibration
Engineering Computations, 2020Co-Authors: Huailiang Zhang, Ling Peng, Wenqian SunAbstract:Purpose To improve the transmission efficiency and reduce the damage to pipes in the hydraulic systems of tunnel boring machine subjected to Random Vibration, this paper aims to propose a novel dynamic characteristic analysis method that considers Random Vibration. Design/methodology/approach A fluid-structure interaction motion equation of the pipe is established by using Hamilton’s principle. The finite element method and discrete analysis method of Random Vibration are used to construct a model of the dynamic behavior of the pipe. Findings The influences of fluid parameters and external excitation parameters on the dynamic characteristics of pipes are analyzed. The experimental results are found to be in good agreement with the simulation results, which demonstrates that the proposed analytical method can provide a theoretical reference for the design and selection of hydraulic pipes subjected to Random Vibration. Originality/value The proposed method can be regarded as a future calculation method for pipes subjected to Random Vibration, and the transmission efficiency of the pipe can be improved.
Adrian Tatnall - One of the best experts on this subject based on the ideXlab platform.
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Dimensional stability of materials subject to Random Vibration
Precision Engineering, 2013Co-Authors: Ruben L. Edeson, Guglielmo S. Aglietti, Adrian TatnallAbstract:High precision stable structures are potentially vulnerable to dimensional instability induced by exposure to Random Vibration. There appears to have been little work in the literature to understand or mitigate structural dimensional instability induced by Random Vibration. To gain more insight into this issue, a novel test was recently developed to assess the plastic strain response in the 10?5 to 10?6 range for structural materials subjected to specific Random Vibration loads. The test was based on a four-point bending configuration with an applied Random base excitation. Two types of material were tested – an Al alloy and a CFRP. This paper presents the test setup and results in detail. The Al alloy samples were found to grow slightly in length during testing, due to a small non-symmetry in the applied load. An FEA model of the test setup was solved in the time domain for a sequence of cyclic loads whose amplitude was based on their probability of exceedance in the Random environment. This model, using nonlinear kinematic hardening, was able to predict the residual strain response observed during testing with good accuracy. The main implication of this finding is that ultra stable structures subject to Random Vibration should be assembled in the most strain-free state possible to avoid loss of dimensional stability due to cyclic hardening.
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The effects of Random Vibration on the dimensional stability of precision structures
2012Co-Authors: Ruben L. Edeson, Guglielmo S. Aglietti, Adrian TatnallAbstract:Precision structures for space-based optical systems are typically subjected to brief periods of Random Vibration during the launch and ground testing phases. Such events pose a potential threat to the dimensional stability of such structures, which may be required to maintain positional tolerances on large optics in the low 10s of microns to meet optical performance requirements. Whilst there is an abundance of information in the literature on structural instability caused by hygrothermal cycling, there appears to have been little work done on the effects of Random Vibration. This issue has recently been addressed at RAL with a series of tests aimed at characterizing the behavior of dimensional instability in structures for high-resolution Earth-imaging cameras subject to Random Vibration. Firstly, a breadboard model of a typical "conventional" CFRP-based optical payload structure was produced and subjected to a range of environmental tests. The effects of Random Vibration were compared to those of other environmental stressors (such as thermal vacuum testing) and found to be significant. Next, controlled tests were performed on specific structural areas in order to assess the specific contributions of each area to overall instability. These tests made use of novel test setups and metrology techniques to assess the dimensional stability response of material samples and bolted joints to Random Vibration exposure. The tests were able to measure dimensional instability, characterize it over a series of tests of increasing Vibration levels, and assess variability in results between identical samples. Finally, a predictive technique using a Finite Element Model with nonlinear kinematic hardening was produced. A time domain solution was obtained, using an analogy to Miner's Rule to determine load cycle amplitudes. This model correlated reasonably well with test results. This paper presents this program of work, and the results. It also proposes ways to minimize and mitigate dimensional instability due to Random Vibration by design, analysis and procedural means.
Haitao Wang - One of the best experts on this subject based on the ideXlab platform.
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Adaptive control of Random Vibration test system
2010 International Conference on Intelligent Control and Information Processing, 2010Co-Authors: Guangfeng Guan, Wei Xiong, Haitao WangAbstract:The Random Vibration adaptive control method is presented based on the Kalman adaptive filter to improve the control precision of Random Vibration test system. The Kalman adaptive filter is used to obtain the on-line inverse model of the device under test (DUT). The time domain signal having a reference power spectral density (PSD) is updated by the inverse model. The reference PSD is replicated by the reproduction of the time domain signal at the output of the DUT. The Random Vibration adaptive control is developed and used for the PSD replication in the hydraulic Vibration table. Test results shows that the algorithm is favorable to improve the control precision of Random Vibration control system.
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Random Vibration control based on adaptive filter
2010 IEEE International Conference on Mechatronics and Automation, 2010Co-Authors: Guangfeng Guan, Wei Xiong, Haitao WangAbstract:The Random Vibration adaptive control method is presented based on the recursive least-squares (RLS) adaptive filter. The power spectral density (PSD) of drive signal is updated based on the off-line identification of frequency response function (FRF) in conventional Random Vibration control system. And the pseudo-Random drive signal generated by the conventional time-frequency transformation has leakage between frequency resolutions. The control precision is difficult to meet with conventional Random Vibration control method. The finite impulse response (FIR) filter is designed with the reference PSD in Random Vibration adaptive control system. And the time domain drive signal is generated by filtering a series of independent white noise. The RLS adaptive filter is designed to obtain the inverse model of the device under test (DUT) based on adaptive inverse control algorithm. The time domain drive signal is filtered by the inverse model so the PSD of the DUT output signal can replicate the reference PSD in high precision. Random Vibration test results show the effectiveness of the proposed algorithm.
