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Simulation Analysis of Torsion Beam Hydroforming Based on the Fluid-Solid Coupling Method 被引量:2
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作者 Yu Huang Jian Li +2 位作者 Jiachun Yang Yongdong Peng Weixuan Zhang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第1期139-156,共18页
Hydroformed parts are widely used in industrial automotive parts because of their higher stiffness and fatigue strength and reduced weight relative to their corresponding cast and welded parts.This paper reports a hyd... Hydroformed parts are widely used in industrial automotive parts because of their higher stiffness and fatigue strength and reduced weight relative to their corresponding cast and welded parts.This paper reports a hydraulicforming experimental platform for rectangular tube fittings that was constructed to conduct an experiment on the hydraulic forming of rectangular tube fittings.A finite element model was established on the basis of the fluid–solid coupling method and simulation analysis.The correctness of the simulation analysis and the feasibility of the fluid–solid coupling method for hydraulic forming simulation analysis were verified by comparing the experimental results with the simulation results.On the basis of the simulation analysis of the hydraulic process of the torsion beam using the fluid–solid coupling method,a sliding mold suitable for the hydroforming of torsion beams was designed for its structural characteristics.The effects of fluid characteristics,shaping pressure,axial feed rate,and friction coefficient on the wall thicknesses of torsions beams during formation were investigated.Fluid movement speed was related to tube deformation.Shaping pressure had a significant effect on rounded corners and straight edges.The axial feed speed was increased,and the uneven distribution of wall thicknesses was effectively improved.Although the friction coefficient had a nonsignificant effect on the wall thickness of the ladder-shaped region,it had a significant influence on a large deformation of wall thickness in the V-shaped area.In this paper,a method of fluid-solid coupling simulation analysis and sliding die is proposed to study the high pressure forming law in torsion beam. 展开更多
关键词 Fluid-solid coupling Hydraulic expansion Rectangular tube torsional beam Wall thickness distribution
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Combined resonance of low pressure cylinder-generator rotor system with bending-torsion coupling
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作者 李军 陈予恕 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2011年第8期957-972,共16页
A nonlinear model of a low pressure cylinder-generator rotor system is presented to study sub-synchronous resonance and combined resonance. Analytical results are obtained by an averaging method. Transition sets and b... A nonlinear model of a low pressure cylinder-generator rotor system is presented to study sub-synchronous resonance and combined resonance. Analytical results are obtained by an averaging method. Transition sets and bifurcation diagrams are obtained based on the singularity theory for the two-state variable system. The bifurcation characteristics are analyzed to provide a basis for the optimal design and fault diagnosis of the rotor system. Finally, the theoretical results are verified with the numerical results. 展开更多
关键词 bending-torsion coupling vibration of rotor system sub-synchronous resonance nonlinear dynamics of rotor combined resonance of bending-torsion coupling vibration
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STUDY ON INFLUENCE OF BENDING-TORSION COUPLING IN AN IMPACTING-RUB ROTOR SYSTEM
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作者 孙政策 徐健学 +1 位作者 周桐 谭宁 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2003年第11期1316-1323,共8页
A mathematical model of an impacting-rub rotor system with bending-torsion coupling was established. It was compared with the model without bending-torsion coupling through the modem nonlinear dynamic theory . It is o... A mathematical model of an impacting-rub rotor system with bending-torsion coupling was established. It was compared with the model without bending-torsion coupling through the modem nonlinear dynamic theory . It is observed that periodical, chaotic, period adding phenomena in them and the two models have a similar bifurcation process in their bifurcation figures . But the influence of bending-torsion on the dynmaic characteristics of the system is not neglected. The results have considerable meanings to analyze and improve the characteristics of an impacting- rub rotor system . 展开更多
关键词 impacting-rub bending-torsion coupling CHAOS period adding
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Spin-Rotation Coupling in Gravitation with Torsion 被引量:1
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作者 QIU Shu-Xia SHAO Cheng-Gang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第3X期473-476,共4页
Based on the theory of gravitation with torsion developed by Hammond [Rep. Prog. Phys. 65 (2002) 599], thc interaction between the intrinsic spin of a particle and the mass source is calculated. It is shown that spi... Based on the theory of gravitation with torsion developed by Hammond [Rep. Prog. Phys. 65 (2002) 599], thc interaction between the intrinsic spin of a particle and the mass source is calculated. It is shown that spin can interact with the gravitimagnetic field created by a rotational mass, where the spin-rotation coupling is also discussed. According to the recent torsion pendulum experiment with polarized electrons by Heckel et al. [Phys. Rev. Left. 97 (2006) 021603], we set a new limit on the value of the torsion coupling constant K as K E [0.53, 0.95], which has improved many orders than the constraints from the early spln-spin experiment with K 〈 2 × 10^14. 展开更多
关键词 torsion SPIN-ROTATION torsion coupling constant
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THE COUPLING METHOD FOR TORSION PROBLEM OF THE SQUARE CROSS-SECTION BAR WITH CRACKS
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作者 赵慧明 董正筑 曹璎珞 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2000年第11期1308-1313,共6页
By coupling natural boundary element method (NBEM) with FEM based on domain decomposition, the torsion problem of the square cross-sections bar with cracks have been studied, the stresses of the nodes of the cross-sec... By coupling natural boundary element method (NBEM) with FEM based on domain decomposition, the torsion problem of the square cross-sections bar with cracks have been studied, the stresses of the nodes of the cross-sections and the stress intensity factors have been calculated, and some distribution pictures of the stresses have been drawn. During computing, the effect of the relaxed factors to the convergence speed of the iterative method has been discussed. The results of the computation have confirmed the advantages of the NBEM and its coupling with the FEM. 展开更多
关键词 natural boundary element method (NBEM) finite element method (FEM) couplE torsion?
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Bending-Torsional Coupled Vibration Test of Large Power Gear Transmission System
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作者 刘辉 项昌乐 +1 位作者 孙恬恬 蔡仲昌 《Journal of Beijing Institute of Technology》 EI CAS 2010年第4期411-415,共5页
In order to test the bending-torsional coupled vibration characteristics of the multi-shafts gear transmission system of large power vehicles,a torsional vibration exciter was used to apply torsional excitation on the... In order to test the bending-torsional coupled vibration characteristics of the multi-shafts gear transmission system of large power vehicles,a torsional vibration exciter was used to apply torsional excitation on the gear transmission systems and thirty-two acceleration sensors were used to measure the tangential acceleration of each shaft.Torsional vibration signals and bending vibration signals of each measuring point were obtained by calculation of the four-point-response signal.The modal parameters of gear transmission systems including nature frequency,modal shape and modal damping ratio were obtained by identifying modal parameters of the torsional vibration signal and bending vibration signal.The characteristic of the bending vibration and torsional vibration of the gear systems were studied through the analysis of the nature frequency and modal shape.The nonlinearity characteristic of the gear transmission system was investigated through single frequency excitation test,which can be the foundation for further nonlinearity research. 展开更多
关键词 bending-torsional coupled gear transmission system modal parameters identify NONLINEARITY
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Linear and nonlinear torsional free vibration of functionally graded micro/nano-tubes based on modified couple stress theory 被引量:2
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作者 A.R.SETOODEH M.REZAEI M.R.ZENDEHDEL SHAHRI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2016年第6期725-740,共16页
The linear and nonlinear torsional free vibration analyses of functionMly graded micro/nuno-tubes (FGMTs) are analytically investigated based on the couple stress theory. The employed non-classical continuum theory ... The linear and nonlinear torsional free vibration analyses of functionMly graded micro/nuno-tubes (FGMTs) are analytically investigated based on the couple stress theory. The employed non-classical continuum theory contains one material length scale parameter, which can capture the small scale effect. The FGMT model accounts for the through-radius power-law variation of a two-constituent material. Hamilton's principle is used to develop the non-classical nonlinear governing equation. To study the effect of the boundary conditions, two types of end conditions, i.e., fixed-fixed and fixed-free, are considered. The derived boundary value governing equation is of the fourthorder, and is solved by the homotopy analysis method (HAM). This method is based on the Taylor series with an embedded parameter and is capable of providing very good approximations by means of only a few terms, if the initial guess and the auxiliary linear operator are properly selected. The analytical expressions are developed for the linear and nonlinear natural frequencies, which can be conveniently used to investigate the effects of the dimensionless length scale parameter, the material gradient index, and the vibration amplitude on the natural frequencies of FGMTs. 展开更多
关键词 torsional vibration nonlinear vibration micro/nano-tube functionallygraded material (FGM) couple stress theory size effect
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TORSIONAL OSCILLATION CHARACTERISTICS OF ROTARY SHAFTS BASED ON TORSION AND BENDING COUPLED VIBRATION 被引量:1
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作者 张俊红 孙少军 +2 位作者 郑勇 高宏阁 程晓鸣 《Transactions of Tianjin University》 EI CAS 2006年第1期72-78,共7页
The torsional oscillation characteristics on the bending and torsioh coupled vibration of rotary shaft system were investigated using the elasto-dynamic theory and other mathematic methods, such as difference approach... The torsional oscillation characteristics on the bending and torsioh coupled vibration of rotary shaft system were investigated using the elasto-dynamic theory and other mathematic methods, such as difference approach, Fourier transform, and wavelet transform. It is concluded that mass eccentricity and other exciting modalities affect the bending and torsion coupled vibration of rotary shafts. Torsional vibration caused by bending vibration features linearity along with the change of amplitude of bending vibration. Meanwhile, energy spectrum concentrates on high frequency area with the wavelet analysis. 展开更多
关键词 rotary shafts torsional vibration feature difference approach wavelet transform coupled vibration
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Coupled lateral-torsional-axial vibrations of a helical gear-rotor-bearing system 被引量:8
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作者 Chao-Feng Li Shi-Hua Zhou +1 位作者 Jie Liu Bang-Chun Wen 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2014年第5期746-761,共16页
Considering the axial and radial loads, a math- ematical model of angular contact ball bearing is deduced with Hertz contact theory. With the coupling effects of lateral, torsional and axial vibrations taken into acco... Considering the axial and radial loads, a math- ematical model of angular contact ball bearing is deduced with Hertz contact theory. With the coupling effects of lateral, torsional and axial vibrations taken into account, a lumped-parameter nonlinear dynamic model of helical gearrotor-bearing system (HGRBS) is established to obtain the transmission system dynamic response to the changes of dif- ferent parameters. The vibration differential equations of the drive system are derived through the Lagrange equation, which considers the kinetic and potential energies, the dis- sipative function and the internal/external excitation. Based on the Runge-Kutta numerical method, the dynamics of the HGRBS is investigated, which describes vibration properties of HGRBS more comprehensively. The results show that the vibration amplitudes have obvious fluctuation, and the frequency multiplication and random frequency components become increasingly obvious with changing rotational speed and eccentricity at gear and bearing positions. Axial vibration of the HGRBS also has some fluctuations. The bearing has self-variable stiffness frequency, which should be avoided in engineering design. In addition, the bearing clearance needs little attention due to its slightly discernible effect on vibration response. It is suggested that a careful examination should be made in modelling the nonlinear dynamic behavior of a helical gear-rotor-bearing system. 展开更多
关键词 Helical gear-rotor-bearing system coupled lateral-torsional-axial vibration Meshing frequency Nonlinear dynamics
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ANALYSIS OF COMPOSITE LAMINATE BEAMS USING COUPLING CROSS-SECTION FINITE ELEMENT METHOD
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作者 姜文光 John L.Henshall 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第12期1709-1718,共10页
Beams and plates manufactured from laminates of composite materials have distinct advantages in a significant number of applications. However, the anisotropy arising from these materials adds a significant degree of c... Beams and plates manufactured from laminates of composite materials have distinct advantages in a significant number of applications. However, the anisotropy arising from these materials adds a significant degree of complexity, and thus time, to the stress and deformation analyses of such components, even using numerical approaches such as finite elements. The analysis of composite laminate beams subjected to uniform extension, bending, and/or twisting loads was performed by a novel implementation of the usual finite element method. Due to the symmetric features of the deformations, only a thin slice of the beam to be analysed needs to be modelled. Conventional threedimensional solid finite elements were used for the structural discretization. The accurate deformation relationships were formulated and implemented through the coupling of nodal translational degrees of freedom in the numerical analysis. A sample solution for a rectangular composite laminate beam is presented to show the validity and accuracy of the proposed method. 展开更多
关键词 composite material beam coupling equation finite element method extension BENDING torsion
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Torsionally coupled dynamic performance analysis of asymmetric offshore platforms subjected to wave and earthquake loadings
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作者 He Xiaoyu and Li Hongnan 1.Zhejiang Provincial Planning,Design & Research Institute of Communications,Hangzhou 310006,China 2.State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian 116024,China 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2010年第2期247-258,共12页
The dynamic equations of motion of asymmetric offshore platforms under three different environmental conditions:seismic action,wave action and their combination are established in this paper. In establishing these mot... The dynamic equations of motion of asymmetric offshore platforms under three different environmental conditions:seismic action,wave action and their combination are established in this paper. In establishing these motion equations,three typical eccentricity types including mass eccentricity,rigidity eccentricity and their combination were considered,as are eccentricities that occur un-idirectionally and bi-directionally. The effects of the eccentricity type,the dynamic characteristics and the environmental conditions on the torsional coupling response of platforms are investigated and compared. An effort has also been made to analyze the inffluence of accidental eccentricity on asymmetric platforms with different eccentricity in two horizontally orthogonal directions. The results are given in terms of non-dimensional parameters,accounting for the uncoupled torsional to lateral frequency ratio. Numerical results reveal that the eccentricity type has a great inffluence on the torsionally coupled response under different environmental conditions. Therefore,it is necessary to consider the combination of earthquake and wave action in the seismic response analysis of some offshore platforms. 展开更多
关键词 offshore platform asymmetric structure accidental eccentricity torsion coupling earthquake load wave load
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Dynamic Characteristics of the Crankshaft System with Coupling Effect 被引量:1
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作者 S.H. Zhang K. Jia 《Journal of Energy and Power Engineering》 2010年第5期18-26,共9页
The nonlinear dynamic model of the marine diesel crankshaft system with a propeller and 6 cranks is established, in which the variable moment of inertia of the linkage and the piston, coupling effect between torsional... The nonlinear dynamic model of the marine diesel crankshaft system with a propeller and 6 cranks is established, in which the variable moment of inertia of the linkage and the piston, coupling effect between torsional and axial vibration, the actuating force applied on the piston, the actuating torque and force applied on the propeller is included. The governing equations of the model denote a strong nonlinear and non autonomous system. By numeric simulation, the dynamic response of the system to initial displacement and initial speed, variable moment of inertia, the pressure applied on the piston by combustion gas, the torque and the axial force applied on the propeller by fluid is researched respectively. According to the research results, the variable moment of inertia and coupling effect between torsional and axial vibration are the fundamental reason for nonlinear vibration. Different actuating factors can not only result in different frequency components of the response, but make the same frequency component have different vibration amplitude. The dynamic behavior of the system is not influenced obviously by the actuating torque and force applied on the propeller. There is obvious difference in sensitivity of the dynamic response in the different direction to the same actuating factor. 展开更多
关键词 coupling effect between torsional and axial vibration nonlinear dynamic model crankshaft system dynamic response.
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Coupled flexural-torsional vibration band gap in periodic beam including warping effect
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作者 方剑宇 郁殿龙 +1 位作者 韩小云 蔡力 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第4期1316-1321,共6页
The propagation of coupled flexural-torsional vibration in the periodic beam including warping effect is investigated with the transfer matrix theory. The band structures of the periodic beam, both including warping e... The propagation of coupled flexural-torsional vibration in the periodic beam including warping effect is investigated with the transfer matrix theory. The band structures of the periodic beam, both including warping effect and ignoring warping effect, are obtained. The frequency response function of the finite periodic beams is simulated with finite element method, which shows large vibration attenuation in the frequency range of the gap as expected. The effect of warping stiffness on the band structure is studied and it is concluded that substantial error can be produced in high frequency range if the effect is ignored. The result including warping effect agrees quite well with the simulated result. 展开更多
关键词 phononic crystals coupled flexural-torsional beam transfer matrix method warpingstiffness
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钻杆纵-扭耦合振动的试验研究
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作者 李欣业 李兴鹏 +2 位作者 李慨 张华彪 陈涛 《振动与冲击》 EI CSCD 北大核心 2024年第4期314-320,共7页
提出了一种新型的钻杆纵-扭耦合振动模拟测试系统。基于该系统设计了单因素试验,研究了驱动转速、进给速度、钻头直径、岩样强度和钻杆刚度对钻杆振动的影响规律,并通过正交试验探究了以上各因素对钻杆振动的影响程度。单因素试验结果表... 提出了一种新型的钻杆纵-扭耦合振动模拟测试系统。基于该系统设计了单因素试验,研究了驱动转速、进给速度、钻头直径、岩样强度和钻杆刚度对钻杆振动的影响规律,并通过正交试验探究了以上各因素对钻杆振动的影响程度。单因素试验结果表明,随着转速的增加,纵向振动幅值先减小后增大,但扭转振动幅值逐渐减小;随着进给速度的增大,纵向振动幅值逐渐减小,但扭转振动的幅值逐渐增大;转速增加导致扭矩和钻压下降,而进给速度增加导致扭矩和钻压上升;采用小直径钻头,低强度岩样,低刚度钻杆均有助于减小钻杆纵向振动幅值,但均导致扭转振动幅值增加。正交试验结果表明,转速对纵向振动的影响程度最大,进给速度对扭转振动的影响程度最大。试验结果与已有钻杆纵-扭耦合振动两自由度模型的数值仿真结果基本吻合。 展开更多
关键词 钻杆 纵-扭耦合振动 单因素试验 正交试验
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考虑约束扭转二次剪力流影响的箱梁畸变效应分析
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作者 王晨光 张元海 《东南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第4期937-943,共7页
为了揭示箱梁约束扭转和畸变之间的耦联关系,研究约束扭转对箱梁畸变效应的影响,根据约束扭转二次剪力流形成的畸变荷载,建立了考虑约束扭转的箱梁畸变控制微分方程.基于乌曼斯基第二理论,提出约束扭转剪力流是基于约束扭转引起的畸变... 为了揭示箱梁约束扭转和畸变之间的耦联关系,研究约束扭转对箱梁畸变效应的影响,根据约束扭转二次剪力流形成的畸变荷载,建立了考虑约束扭转的箱梁畸变控制微分方程.基于乌曼斯基第二理论,提出约束扭转剪力流是基于约束扭转引起的畸变效应修正后的总扭矩布雷特剪力流,并通过Ansys有限元模型和能量法计算结果对理论公式进行了验证.数值算例结果表明:2种不同约束扭转剪力流分解方法计算所得结果完全一致;不同计算点处的约束扭转剪应力与Ansys有限元法计算结果吻合良好;扭转畸变翘曲总正应力、畸变翘曲正应力均与按能量法计算所得结果吻合良好,误差不超过10%.计入约束扭转二次剪应力的影响能够更准确地计算箱梁畸变效应. 展开更多
关键词 箱梁 约束扭转 畸变效应 耦联分析
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钻柱的黏滑与高频扭转耦合振动测量与分析
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作者 李玉梅 邓杨林 +2 位作者 张涛 于丽维 刘明 《石油机械》 北大核心 2024年第5期40-46,共7页
钻井系统的自激扭转振动会导致钻头和地层之间的接触力或切削力相对速度出现下降特征。为减轻这种机制的影响,通过对三轴振动的时域、频域分析,研究了钻柱扭转振动特征。研究结果发现,低频的扭转振动会引发黏滑振动,黏滑振动频率为0.128... 钻井系统的自激扭转振动会导致钻头和地层之间的接触力或切削力相对速度出现下降特征。为减轻这种机制的影响,通过对三轴振动的时域、频域分析,研究了钻柱扭转振动特征。研究结果发现,低频的扭转振动会引发黏滑振动,黏滑振动频率为0.128 Hz,三轴振动和转速会出现周期性波动。钻柱发生高频扭转振动(HFTO)时,三轴加速度都出现了177.2 Hz的主频率。时域分析发现,切向加速度远大于轴向和法向加速度峰值,均方根值也较高,表明切向振动波动较大、能量高,说明此时井下正发生扭转振动。黏滑与HFTO发生耦合时,法向加速度会出现2个主频,即黏滑时的主频和HFTO的主频。高扭转频率会提高扭矩和机械转速导致钻具疲惫。研究结果对描述扭转振动的特征,判断钻井过程是否发生黏滑、HFTO和及时采取消除黏滑振动、缓解钻具疲惫技术措施具有指导作用。 展开更多
关键词 钻柱 扭转振动 黏滑 高频扭转振动 频率 振动耦合
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基于同频弯扭耦合强迫振动的桥梁断面颤振导数识别方法改进
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作者 唐煜 杨源远 华旭刚 《铁道科学与工程学报》 EI CAS CSCD 北大核心 2024年第4期1656-1666,共11页
为拓展强迫振动法在桥梁断面颤振导数识别领域中的应用能力,采取让断面做2次同频异相的弯扭耦合简谐运动模式,理论推导出任意非零相位差条件下的桥梁断面颤振导数识别公式。以理想平板的Theodorsen解为气动力数据源,对该方法的识别能力... 为拓展强迫振动法在桥梁断面颤振导数识别领域中的应用能力,采取让断面做2次同频异相的弯扭耦合简谐运动模式,理论推导出任意非零相位差条件下的桥梁断面颤振导数识别公式。以理想平板的Theodorsen解为气动力数据源,对该方法的识别能力进行数值验证,并在此基础上研究弯扭耦合运动相位差、高斯白噪声、整数倍频有色噪声对平板颤振导数识别结果的影响规律。基于Fluent软件,将该方法与计算流体动力学(Computational Fluid Dynamics,CFD)技术结合,识别得到丹麦大带东桥主梁断面的颤振导数。研究结果表明:当平板气动力不包含噪声时,在任意非零相位差取值条件下,按照该方法识别所得颤振导数结果与理论值完全吻合;当平板气动力含有高斯白噪声时,在考察的3个低水平噪声条件下(5%、10%、15%),颤振导数识别误差与高斯白噪声比例水平、折算风速均成正相关,但不同颤振导数对高斯白噪声敏感程度各异;当平板气动力包含整数倍频有色噪声时,3倍频、4倍频噪声对颤振导数的识别精度影响显著,其他低倍频噪声和超高倍频噪声的影响较小,在8个颤振导数的识别结果中,H_(2)^(*)、H_(4)^(*)、A_(2)^(*)、A_(4)^(*)对倍频有色噪声更敏感。应用该方法结合CFD数值模拟识别得到的大带东桥主梁颤振导数与既有文献结果吻合良好,经计算得到的颤振临界风速也较为接近。研究结果可满足同类桥梁颤振设计的工程计算需求。 展开更多
关键词 桥梁工程 颤振导数识别 强迫振动 弯扭耦合 计算流体动力学
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不同类别场地近断层地震动平-扭耦合作用对结构动力响应影响分析
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作者 韩淼 张浦源 +1 位作者 杜红凯 刘永波 《工程抗震与加固改造》 北大核心 2024年第4期12-20,35,共10页
为研究不同场地近断层地震动作用下结构动力响应,建立钢框架结构模型,选取I类、Ⅱ类和Ⅲ类场地近断层地震波各10条,分析地震动平动分量与扭转分量耦合作用对结构动力响应的影响。结果表明:平动分量耦合扭转分量相比平动分量单独作用,随... 为研究不同场地近断层地震动作用下结构动力响应,建立钢框架结构模型,选取I类、Ⅱ类和Ⅲ类场地近断层地震波各10条,分析地震动平动分量与扭转分量耦合作用对结构动力响应的影响。结果表明:平动分量耦合扭转分量相比平动分量单独作用,随场地类别由Ⅰ类到Ⅲ类,各层楼面的角柱与边柱动力响应均有增大,Ⅲ类场地上角柱动力响应的增幅最大,层间加速度增幅22.51%,层间位移角增幅21.68%,柱端剪力增幅10.70%,柱端弯矩增幅22.56%;场地类别相同时,同层楼面的角柱和边柱的动力响应增大,角柱增幅最大,边柱次之。结构设计中需考虑近断层地震动平-扭耦合作用对不同类别场地结构的角柱与边柱动力响应影响。 展开更多
关键词 近断层地震 扭转分量 场地类别 耦合作用 动力响应
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某大型水电站机组特定负荷区间厂房振动噪声成因分析与探讨
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作者 韩伶俐 高瑜 《水力发电》 CAS 2024年第7期59-64,共6页
某大型水电站机组在低水头特定负荷区间运行时厂房出现低沉的轰鸣噪声,并伴随厂房楼板、楼梯明显振动的现象,参建各方对引起该异常现象的原因进行了逐一排查但至今尚未解决。对此进行了机组变水位稳定性和能量试验,根据试验成果对机组... 某大型水电站机组在低水头特定负荷区间运行时厂房出现低沉的轰鸣噪声,并伴随厂房楼板、楼梯明显振动的现象,参建各方对引起该异常现象的原因进行了逐一排查但至今尚未解决。对此进行了机组变水位稳定性和能量试验,根据试验成果对机组及厂房结构耦合振动成因进行了分析与推测,初步判断原因为固定导叶卡门涡激发了活动导叶的弯扭耦合共振,通过轴承和顶盖传导至混凝土,并导致母线层楼板及下方立柱发生共振。 展开更多
关键词 弯扭耦合振动 共振 噪声 振动 水电站
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基于流固耦合的单轴跟踪式光伏结构风致扭转研究
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作者 李正农 伍世芳 《太阳能学报》 EI CAS CSCD 北大核心 2024年第6期316-324,共9页
以某跟踪式光伏发电系统为研究对象,通过编写自定义程序代码UDF对Fluent进行二次开发,建立单轴跟踪式光伏结构的二维模型,研究其在风荷载作用下的扭转振动问题。研究结果表明:风速达到某一特值后,结构出现等幅周期性振动,发生软颤振现象... 以某跟踪式光伏发电系统为研究对象,通过编写自定义程序代码UDF对Fluent进行二次开发,建立单轴跟踪式光伏结构的二维模型,研究其在风荷载作用下的扭转振动问题。研究结果表明:风速达到某一特值后,结构出现等幅周期性振动,发生软颤振现象,而其阻尼比对抑制扭转振动有一定的作用,这同实际情况较吻合;光伏组件倾角在0°~20°范围内时,倾角越大,扭转振动的临界风速越低。 展开更多
关键词 太阳能 光伏组件 风效应 流固耦合 扭转振动 阻尼
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