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of parameters on the low-speed performance was studied. The results show that the instability of the system is mainly caused by the negative damping characteristic of the nonlinear friction. Thus, the system stability can be effectively improved by the reduction of the negative damping value of the friction or the increase of the load’s damping value, and the response delay can be shortened......
the undamped electromechanical modes to a prescribed zone in the s-plane. The problem of robus t UPFC based damping controller is formulated as an optimization problem according to the eigenvalue-based multi-objective func tion comprising the damping factor, and the damping ratio of the undamped electromechanical modes to be solved using gravitational search algorithm (GSA) that has a strong ability......
resin as a composite structure, and the damping properties of the composite were tested by dynamic mechanical analyzer (DMA). The results show that the films annealed for 90 minutes present a dense and compact crystal arrangement on the surface; moreover, the films also achieve their best electric quality. At the same time, the largest damping loss factor of the composite constructed with the 90 mins......
and damping contact force models of gear system WU Lijuan, TANG Jinyuan, CHEN Siyu (State Key Laboratory of High Performance and Complex Manufacturing, School of Mechanical and Electrical Engineering, Central... contact force models, Kelvin-Voigt (KV) contact force model and nonlinear spring and damping (NSD) contact force model. The dimensionless velocity was regarded as the controlling parameter, the Runge-Kutta......
, e.g., high-specific strength and modulus, good wear resistance, and damping capacity. As compared with aluminum matrix composites, magnesium matrix composites have merit in their specific weight... finally summarized for magnesium matrix composites including tensile response, wear resistance, creep behavior, and damping capacity.关键词:......
including multi-valued solutions, jump phenomenon, hardening stiffness are found. The effects of the equivalent damping and the loads of the system under the stick-slip oscillation are analyzed. It shows that the change of the load can obviously influence the resonance frequency of the system and have little effect on the steady-state response amplitude of the system. The damping of the system......
of steel-spring floating slab track(FST), semi-active magneto-rheological(MR) damping technology was embedded with FST. A vertical dynamic model involving vehicle and steel-spring FST isolated by MR...-linear vibration response characteristics of steel-spring FST supported by semi-active MR dampers were investigated. The results show that MR damping force can increase the safe allowance of vertical FST......
to simulate the radiation damping of their infinite foundations, and based on the Marc software, a simplified seismic motion input method is presented by the equivalent nodal loads. Finally, based on the practical engineering of a RCC gravity dam, effects of radiation damping and construction interfaces on the dynamic characteristics of dams are investigated in detail. Analysis results show that dynamic......
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纳米级硅灰及碳管对水泥基材料减振性能的影响 段忠东1,李惠1,罗健林1 (1.哈尔滨工业大学,土木工程学院,哈尔滨,150090) 摘要:将纳米级超细硅灰(USF)或/与多壁纳米碳管(MWCNT)引入水泥基体制备了3组纳米复合材料,并制备了参比试件(Plain/C).先后采用自由衰减,半功率带宽法及三点弯曲法测试相应试件的阻尼系数(ζ)及抗折强度(σ),以评价USF或/与MWCNT对水泥基减振及力学性能的影响.结果表明:与Plain/C相比,USF的微填充及火山灰效应可显著提高基体的σ,但不利于ζ的提升;中空管状MWCNT的位错,黏滞效应可使复合材料具有良好的减振性能,但分散较差时,MW......
