Journal articles: 'Dynamic responses'

1

Vinson, V. K. "Dynamic Responses." Science Signaling 5, no. 229 (June 19, 2012): ec172-ec172. http://dx.doi.org/10.1126/scisignal.2003310.

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Burgess, Darren J. "Dynamic omics responses." Nature Reviews Genetics 13, no. 12 (November 14, 2012): 828. http://dx.doi.org/10.1038/nrg3370.

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Song, Ohseop, and Sung-Kyun Kim. "1510 Dynamic Responses of Composite H-Type Cross-Section Beams." Proceedings of The Computational Mechanics Conference 2010.23 (2010): 600–602. http://dx.doi.org/10.1299/jsmecmd.2010.23.600.

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Lin, Yu Sen, Li Hua Xin, and Min Xiang. "Parameters Analysis of Train Running Performance on High-Speed Bridge during Earthquake." Advanced Materials Research 163-167 (December 2010): 4457–63. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.4457.

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A model of coupled vehicle-bridge system excited by earthquake and irregular track is established for studying train running performance on high-speed bridge during earthquake, by the methods of bridge structure dynamics and vehicle dynamics. The results indicate that under Qian’an earthquake waves vehicle dynamical responses hardly vary with the increasing-height pier, but vehicle dynamical responses increase evidently while the height of pier is 18m, which the natural vibration frequency is approaching to dominant frequency of earthquake waves. Dynamic responses are linearly increasing with earthquake wave strength. Dynamic response of vehicles including lateral car body accelerations and every safety evaluation index all increase with train speed, so the influences of train speed must be taken into account in evaluating running safety of vehicles on bridge during earthquakes, but lateral displacement of bridge is varying irregularly. Dynamic responses and lateral displacement of bridge reduce under the higher dominant frequency of earthquake wave. Derailment coefficient, later wheel-rail force and lateral vehicle acceleration become small with increasing damping ratio. Vertical vehicle acceleration and reduction rate of wheel load are hardly varying with damping ratio.

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Hua, Xia, and Eric Gandee. "Vibration and dynamics analysis of electric vehicle drivetrains." Journal of Low Frequency Noise, Vibration and Active Control 40, no. 3 (February 27, 2021): 1241–51. http://dx.doi.org/10.1177/1461348420979204.

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The importance of the vibration and dynamics of electric vehicle drivetrains has increased because of noise and durability concerns. In this study, the important dynamic responses of drivetrains, including the dynamic mesh force acting at the gear teeth, dynamic loads acting at the bearings, and torsional fluctuation of the tire or load under major vibration excitations, such as motor torque fluctuation excitation and spiral bevel gear mesh excitation, were investigated. The results demonstrate that at a lower motor speed, dynamic responses such as the dynamic mesh force, dynamic bearing loads, and dynamic torsional displacement of the tire or load under motor torque fluctuation are dominant. At a higher motor speed, however, the dynamic responses under the gear mesh excitation are dominant. In addition, increasing the pinion-motor torsional compliance is an effective approach for suppressing the dynamic responses of drivetrains under motor torque fluctuation.

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Anjneya, Kumar, and Koushik Roy. "Response surface-based structural damage identification using dynamic responses." Structures 29 (February 2021): 1047–58. http://dx.doi.org/10.1016/j.istruc.2020.11.033.

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Ozaki, Yu-ichi, Satoru Sasagawa, and Shinya Kuroda. "Dynamic Characteristics of Transient Responses." Journal of Biochemistry 137, no. 6 (June 1, 2005): 659–63. http://dx.doi.org/10.1093/jb/mvi084.

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Chapman, J. M. "Dynamic Responses to the Environment." Biological Journal of the Linnean Society 34, no. 3 (July 1988): 191. http://dx.doi.org/10.1111/j.1095-8312.1988.tb01957.x.

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9

Hossack, Kenneth F. "Cardiovascular Responses to Dynamic Exercise." Cardiology Clinics 5, no. 2 (May 1987): 147–56. http://dx.doi.org/10.1016/s0733-8651(18)30542-3.

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10

Loizou, Elena, Paul Butler, Lionel Porcar, and Gudrun Schmidt. "Dynamic Responses in Nanocomposite Hydrogels." Macromolecules 39, no. 4 (February 2006): 1614–19. http://dx.doi.org/10.1021/ma0517547.

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11

Bai, Zheng Feng, Xing Gui Wang, and Yang Zhao. "Investigation on Dynamic Responses of Manipulator with Multiple Clearance Joints." Applied Mechanics and Materials 251 (December 2012): 152–57. http://dx.doi.org/10.4028/www.scientific.net/amm.251.152.

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The existence of clearance in joints of manipulator system is inevitable and the movements of the real manipulator are deflection from the ideal manipulator for the clearances. In this study, the effects of clearance on dynamic responses of real manipulator system with multiple clearance joints are investigated using a computational methodology. By applying the nonlinear continuous contact force model, the contact dynamics model in joint clearance is established and the friction effect is considered with the help of Coulomb friction model. Then the dynamics simulation is carried out and the dynamic characteristics of manipulator system with multiple clearance joints are investigated. The results show that the clearance leads to degradation of dynamic performance of the real manipulator system.

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Zhan, Bing Lai, Yue Xu, Zhi Xu, and Xiqin Yang. "Dynamic Properties Analysis for Self-Anchored Suspension and Cable-Stayed Combination System Bridge." Advanced Materials Research 255-260 (May 2011): 1077–81. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.1077.

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In view that dynamics research for self-anchored suspension and cable-stayed combination system bridge lags behind the practical application, this thesis analyzed its dynamic properties and seismic responses. By means of constructing a dynamic finite element model of the bridge for the dynamic properties and seismic response analysis, the thesis discovered the dynamic properties and the seismic responses laws of self-anchored suspension and cable-stayed combination system bridge. The dynamic finite element model was constructed based on the dynamic analysis theory and method, under the background of the first self-anchored suspension and cable-stayed combination system bridge in the world, and it was verifyed by on-site vibration test. The dynamic properties and the seismic responses laws provides a valuable reference for the design and maintenance of this type of bridge.

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13

Yuan, Ying Cai, Yan Li, and Yi Ming Wang. "Robust Design to Control the Chaos of Fold Mechanism with Clearance." Applied Mechanics and Materials 312 (February 2013): 153–57. http://dx.doi.org/10.4028/www.scientific.net/amm.312.153.

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With the increasing of web offset printing machines working speed, the nonlinear dynamics responses are more significant, even the fold mechanism with clearances appears some chaos phenomenon. Based on the dynamic model of fold mechanism, the nonlinear dynamics responses and the chaos movement in pair are studied. Used the performance parameters and dynamics response sensitivities as the goal values, the robust design model is established. By the robust design model, the nonlinear dynamic responses and chaos phenomenon can be under controlled in the same clearance degree. In this way, the performance of fold mechanism may be improved.

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14

Publicover, N. G. "Dynamic responses of electrically coupled systems." Journal of General Physiology 87, no. 4 (April 1, 1986): 513–31. http://dx.doi.org/10.1085/jgp.87.4.513.

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An identified pair of electrically coupled neurons in the buccal ganglion of the freshwater snail Helisoma trivolvis is an experimentally accessible model of electrical synaptic transmission. In this investigation, electrical synaptic transmission is characterized using sinusoidal frequency (Bode) responses computed by Laplace transforms and responses to brief stimuli. The frequency response of the injected neuron shows a 20-dB/decade attenuation and a phase shift from 0 degree at low frequencies to -90 degrees at high frequencies. The response of a coupled cell shows a 40-dB/decade attenuation and a phase shift from 0 degrees at low frequencies to -180 degrees at high frequencies. A simple mathematical model of electrical synaptic transmission is described that displays each of these crucial features of the measured frequency responses. Methods are described to estimate the frequency responses of coupled systems based on presynaptic measurements. The responses of the coupled system to brief pulses of current were computed using the principle of superposition. The electrical properties of coupled systems impose a minimum delay in reaching a peak in all postsynaptic responses. The delays in the postsynaptic responses to brief stimuli are related to the electrical and anatomical parameters of coupled networks.

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15

Chen, Xiulong, Shuai Jiang, and Yu Deng. "Dynamic Responses of Planar Multilink Mechanism considering Mixed Clearances." Shock and Vibration 2020 (March 16, 2020): 1–18. http://dx.doi.org/10.1155/2020/8725845.

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Translational and revolute joints are the main kinds of joints in planar multilink mechanisms. Translational and revolute clearance joints have great influence on dynamical responses of planar mechanisms. Most research studies mainly focused upon revolute clearance of planar mechanisms based upon the modified Coulomb friction model, some studies investigated clearance of the pin-slot joint, and few studies researched mixed clearances (considering both translational clearance and revolute clearance) based on the LuGre friction model. Dynamic response of the 2-DOF nine-bar mechanism considering mixed clearances based on the LuGre model is investigated in this work. The dynamic model with mixed clearances is built by the Lagrange multipliers. Dynamic responses including motion output of the slider, driving torques, contact forces, shaft center trajectories at revolute clearance pairs, and slider trajectory inside the guide are analyzed, respectively. Influences of different friction models on dynamic responses are studied, such as LuGre and modified Coulomb’s friction models. Effects of different clearance values and different driving speeds on dynamic responses with mixed clearances are both analyzed. Virtual prototype model considering mixed clearances is carried out through ADAMS to verify correctness.

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16

Liu, Q., J. Zhang, L. Gu, and L. Yan. "An Accurate Method for First and Second Derivatives of Dynamic Responses." Journal of Mechanics 27, no. 3 (August 31, 2011): 389–98. http://dx.doi.org/10.1017/jmech.2011.41.

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ABSTRACTThis paper has developed an accurate method for calculating the first and second derivatives of dynamic responses with respect to the design variables of structures subjected to dynamic loads. An efficient algorithm to calculate the dynamic responses, their first and second derivatives with respect to the design variables is formulated based on the Newmark-β method. The algorithm is achieved by direct differentiation and only a single dynamics analysis is required. An example is demonstrated with the new method proposed in this paper and the analytical method. The comparative numerical results show the new method is highly accurate compared to the analytical method.

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17

Song, Xiang Hua, Guang Ping Zou, and Wei Guang An. "Dynamic Responses of Supercavitating Vehicles under Non-Stationary Random Excitation." Advanced Materials Research 591-593 (November 2012): 1934–37. http://dx.doi.org/10.4028/www.scientific.net/amr.591-593.1934.

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When the front end of the supercavitating vehicles subjects to very large axial non-stationary random excitation at high speed motion under water, it is necessary to analyze dynamic responses of supercavitating vehicles under non-stationary random excitation. The dynamical equation of supercavitating vehicles is transformed into the form of state equations. The Simpson integration method is going to calculate the integral term of the general solution of state equation to improve the precise integration method. The explicit expression of dynamic responses of supercavitating vehicles is deduced, the means and variances of structural responses are calculated with operation laws of the first moment and second moment. Under different sailing speeds and different cone-cavitator angles dynamic responses of supercavitating vehicles are given by the examples, and the effectiveness of the method was demonstrated.

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18

Spiga, Francesca, Eder Zavala, Jamie J. Walker, Zidong Zhao, John R. Terry, and Stafford L. Lightman. "Dynamic responses of the adrenal steroidogenic regulatory network." Proceedings of the National Academy of Sciences 114, no. 31 (July 17, 2017): E6466—E6474. http://dx.doi.org/10.1073/pnas.1703779114.

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The hypothalamic–pituitary–adrenal axis is a dynamic system regulating glucocorticoid hormone synthesis in the adrenal glands. Many key factors within the adrenal steroidogenic pathway have been identified and studied, but little is known about how these factors function collectively as a dynamic network of interacting components. To investigate this, we developed a mathematical model of the adrenal steroidogenic regulatory network that accounts for key regulatory processes occurring at different timescales. We used our model to predict the time evolution of steroidogenesis in response to physiological adrenocorticotropic hormone (ACTH) perturbations, ranging from basal pulses to larger stress-like stimulations (e.g., inflammatory stress). Testing these predictions experimentally in the rat, our results show that the steroidogenic regulatory network architecture is sufficient to respond to both small and large ACTH perturbations, but coupling this regulatory network with the immune pathway is necessary to explain the dissociated dynamics between ACTH and glucocorticoids observed under conditions of inflammatory stress.

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19

QI, Shengwen. "General regularity of dynamic responses of slopes under dynamic input." Science in China Series E 46, no. 7 (2004): 120. http://dx.doi.org/10.1360/03ez0006.

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20

Yang, Yanxia, Xu Luo, Chaohua Dai, Weirong Chen, Zhixiang Liu, and Qi Li. "Dynamic modeling and dynamic responses of grid-connected fuel cell." International Journal of Hydrogen Energy 39, no. 26 (September 2014): 14296–305. http://dx.doi.org/10.1016/j.ijhydene.2014.05.026.

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21

Li, Zhen Xia, and Yuan Zhao Chen. "Dynamic Analysis of Bridge-Approach Embankment Transition Segment." Applied Mechanics and Materials 238 (November 2012): 719–22. http://dx.doi.org/10.4028/www.scientific.net/amm.238.719.

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Dynamic responses of coupled system were analyzed when the speed of train was 350km/h and the transition was filled with graded broken stones mixed 5% cement. Results indicate that setting form of bridge-approach embankment section has little effect on dynamic responses, thus designers can choose it on account of practical circumstances. Based on the study from vehicle-track dynamics, we suggest that the coefficient of subgrade reaction (K30) should be greater than 190MPa within 0-5m zone behind abutment and be greater than 150MPa in other zones.

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22

Choi, Chiu H. "Shaping of Dynamic Responses by Observers." Open Automation and Control Systems Journal 5, no. 1 (March 22, 2013): 1–6. http://dx.doi.org/10.2174/1874444301305010001.

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23

Germain, Ronald N. "Imaging dynamic interactions in immune responses." Seminars in Immunology 17, no. 6 (December 2005): 385–86. http://dx.doi.org/10.1016/j.smim.2005.10.001.

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24

Van den Berghe, Greet. "Dynamic neuroendocrine responses to critical illness." Frontiers in Neuroendocrinology 23, no. 4 (October 2002): 370–91. http://dx.doi.org/10.1016/s0091-3022(02)00006-7.

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25

Chen, C. C., S. J. Kiebel, and K. J. Friston. "Dynamic causal modelling of induced responses." NeuroImage 41, no. 4 (July 2008): 1293–312. http://dx.doi.org/10.1016/j.neuroimage.2008.03.026.

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26

BROWN, B. G. "DYNAMIC RESPONSES OF HUMAN CORONARY STENOSES." Australian and New Zealand Journal of Medicine 16, no. 3 (June 1986): 325–27. http://dx.doi.org/10.1111/j.1445-5994.1986.tb01178.x.

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27

SMUCKER, A. J. M., and R. M. AIKEN. "DYNAMIC ROOT RESPONSES TO WATER DEFICITS." Soil Science 154, no. 4 (October 1992): 281–89. http://dx.doi.org/10.1097/00010694-199210000-00004.

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28

Lybbert, Travis J., and Christopher B. Barrett. "Risk Responses to Dynamic Asset Thresholds." Review of Agricultural Economics 29, no. 3 (September 2007): 412–18. http://dx.doi.org/10.1111/j.1467-9353.2007.00354.x.

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29

Dusseau, Ralph Alan, Ramzi El‐Achkar, and Michel Haddad. "Dynamic Responses of Pipeline Suspension Bridges." Journal of Transportation Engineering 117, no. 1 (January 1991): 3–22. http://dx.doi.org/10.1061/(asce)0733-947x(1991)117:1(3).

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30

Lu, Xiaobing, Xuhui Zhang, and Shuyun Wang. "Editorial: Dynamic Responses of Bucket Foundations." Open Ocean Engineering Journal 3, no. 2 (March 5, 2010): 18–19. http://dx.doi.org/10.2174/1874835x01003020018.

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31

Jones, Mari Riess, and Marilyn Boltz. "Dynamic attending and responses to time." Psychological Review 96, no. 3 (July 1989): 459–91. http://dx.doi.org/10.1037/0033-295x.96.3.459.

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32

Menzinger, M., V. Yakhnin, A. Jaree, P. L. Silveston, and R. R. Hudgins. "Dynamic responses of packed bed reactors." Chemical Engineering Science 59, no. 19 (October 2004): 4011–22. http://dx.doi.org/10.1016/j.ces.2004.05.031.

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33

Schultz, Benjamin G., Rachel M. Brown, and Sonja A. Kotz. "Dynamic acoustic salience evokes motor responses." Cortex 134 (January 2021): 320–32. http://dx.doi.org/10.1016/j.cortex.2020.10.019.

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Rasmussen, Morten, Juleen R. Zierath, and Romain Barrès. "Dynamic epigenetic responses to muscle contraction." Drug Discovery Today 19, no. 7 (July 2014): 1010–14. http://dx.doi.org/10.1016/j.drudis.2014.03.003.

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35

Yang, Chang Wei, Jian Jing Zhang, and Chuan Bin Zhu. "Analysis of Dynamic Responses of Bridge-Subgrade Transition of High-Speed Railway." Applied Mechanics and Materials 90-93 (September 2011): 189–96. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.189.

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Referred the vehicle-track coupling dynamics theory [1] and the vertical dynamic analysis models of Bridge-Subgrade transition developed by Zhai [2] ，Wang [3] and others [4]. This article takes account of the interaction between different structural layers in the subgrade system further by using the dynamic ballastless track model and finally establishes a space dynamic numerical model of the vehicle-track-subgrade coupled system. The dynamic response of the coupled system is analyzed when the speed of the train is 350km/h and the transition is filled with graded broken stones mixed with cement of 3%. Results show that the setting forms of Bridge-Subgrade transition have little effect on the dynamic responses, so designers can choose it on account of the practical situation. Due to the location away from abutment about 5m has greater deformation; the stiffness within 5m should be designed alone. Based on the study from vehicle-track dynamics, we suggest that the maximum allowable track deflection angle is 0.9‰ and K30190Mpa within 5m behind the abutment.

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36

Meyer, Christian, Srikanth Padmala, and Luiz Pessoa. "Dynamic Threat Processing." Journal of Cognitive Neuroscience 31, no. 4 (April 2019): 522–42. http://dx.doi.org/10.1162/jocn_a_01363.

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During real-life situations, multiple factors interact dynamically to determine threat level. In the current fMRI study involving healthy adult human volunteers, we investigated interactions between proximity, direction (approach vs. retreat), and speed during a dynamic threat-of-shock paradigm. As a measure of threat-evoked physiological arousal, skin conductance responses were recorded during fMRI scanning. Some brain regions tracked individual threat-related factors, and others were also sensitive to combinations of these variables. In particular, signals in the anterior insula tracked the interaction between proximity and direction where approach versus retreat responses were stronger when threat was closer compared with farther. A parallel proximity-by-direction interaction was also observed in physiological skin conductance responses. In the right amygdala, we observed a proximity by direction interaction, but intriguingly in the opposite direction as the anterior insula; retreat versus approach responses were stronger when threat was closer compared with farther. In the right bed nucleus of the stria terminalis, we observed an effect of threat proximity, whereas in the right periaqueductal gray/midbrain we observed an effect of threat direction and a proximity by direction by speed interaction (the latter was detected in exploratory analyses but not in a voxelwise fashion). Together, our study refines our understanding of the brain mechanisms involved during aversive anticipation in the human brain. Importantly, it emphasizes that threat processing should be understood in a manner that is both context-sensitive and dynamic.

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Cao, Yang, Wang Ping, Wei Hua Zhao, and Cai You Zhao. "The Influences on Turnout Dynamic Responses due to its Irregularities." Applied Mechanics and Materials 105-107 (September 2011): 1181–86. http://dx.doi.org/10.4028/www.scientific.net/amm.105-107.1181.

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A vehicle model and a movable-point simple turnout model were established, and the influences on dynamic responses caused by turnout irregularities when train passes through No.18 turnout was analyzed by using the turnout dynamics simulation software based on finite element method. It shows that turnout dynamic responses are influenced by the combined effects of various types of irregularities, which produce bigger dynamic response than single irregularity. In the turnout devise and use, the distance between slide plate and switch rail or nose rail should be as close as possible, the position arrangements of traction points should be optimized and the insufficient displacement should be eliminated as much as possible; No.18 turnout structure design is reasonable, which can ensure the safety and the stability when train passes over turnout.

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38

Wang, Lei, Xiaojun Wang, and Xiao Li. "Inverse system method for dynamic loads identification via noisy measured dynamic responses." Engineering Computations 33, no. 4 (June 13, 2016): 1070–94. http://dx.doi.org/10.1108/ec-04-2015-0103.

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Purpose – The purpose of this paper is to focus on the influences of the uncertain dynamic responses on the reconstruction of loads. Design/methodology/approach – Based on the assumption of unknown-but-bounded (UBB) noise, a time-domain approach to estimate the uncertain time-dependent external loads is presented by combining the inverse system method in modern control theory and interval analysis in interval mathematics. Inspired by the concept of set membership identification in control theory, an interval analysis model of external loads time history, which is indeed a region or feasible set containing all possible loads being consistent with the bounded structural acceleration responses is established and further solved by two interval algorithms. Findings – Unlike traditional loads identification methods which only give a point estimation, an interval estimation of external loads time history, which is a region containing all the possible loads being consistent with the uncertain structural responses, is determined. The correlation characteristics among the responses of acceleration, velocity, and displacement are also discussed in consideration of the UBB uncertainty. Originality/value – For one hand, the solution of the inverse problem in original system is transformed to the solution of the direct problem in inverse system; for another, the authors deal with the uncertainty by use of interval analysis method, and the identified interval process, which contains any possible external loads time history being consistent with the bounded structural responses can be approximately obtained.

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YAMAZAKI, YUTAKA, MASAYOSHI NAKASHIMA, TAKASHI KAMINOSONO, YUKIO IZAKI, and KATSUMA MAEDA. "CORRELATION BETWEEN SHAKING TABLE AND PSEUDO DYNAMIC RESPONSES : Earthquake response simulation capacity of pseudo dynamic testing." Journal of Structural and Construction Engineering (Transactions of AIJ) 364 (1986): 23–32. http://dx.doi.org/10.3130/aijsx.364.0_23.

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Kaewunruen, Sakdirat, Chayut Ngamkhanong, and Xin Liu. "Spectro-Temporal Responses of Curved Railway Tracks with Variable Radii of Arc Curves." International Journal of Structural Stability and Dynamics 19, no. 04 (April 2019): 1950044. http://dx.doi.org/10.1142/s0219455419500445.

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On curved railway tracks, wheel/rail interface can usually cause a traveling source of sound and vibration, which constitutes high-pitch or tonal noise pollution causing considerable concern to rail asset owners, commuters and people living or working along the railway corridor. The sound and vibration can be in various forms and spectra. The undesirable tonal sound on curves caused by excessive lateral wheel/rail dynamics in resonance with falling friction states are often called ‘squeal noises’. This paper evaluates the transient effect of curve radii on the possible occurrence of lateral track resonances, which is a principal cause of dynamic wheel/rail mode coupling that could trigger ‘curve squeal’. This study is devoted to systems thinking approach and better insight into dynamic phenomena of railway tracks that could resolve the railway curve noise problems. Curved track models in three-dimensional space have been developed using a finite element package, STRAND7. The dynamic responses of curved track have been simulated by applying a moving train load. The transient loading model of a common wheel/rail slip has been adopted. The simulations of railway tracks with different curve radii have been carried out to develop state-of-the-art understanding of lateral track dynamics, including rail dynamics, cant dynamics and overall track responses. Parametric studies have been conducted to evaluate lateral displacements, velocities and accelerations of rail over sleeper and rail at midspan, both in static and dynamic conditions. The study firstly reveals that the lateral resonance of tangent tracks is relatively rare and the mode coupling behavior is unlikely to occur on moderately curved tracks. The lateral vibration responses have been presented in terms of time histories and spectro-temporal responses (also called “Spectogram”). The dynamic lateral responses of the track are found to be sensitive to the change of curved radii. The resonance peak in the lateral direction is related to the agreement of corresponding natural frequencies of rail and the vibration excitation frequencies under an individual rolling velocity. The outcome of this study establishes new insight into the dominant influences of different track parameters to track lateral dynamic behaviors.

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41

Ye, Wei, Xiao Zhen Li, Hong Duan, Chun Sheng Shan, and Xiao Han Liu. "Analytical Solution for Vertical Dynamic Response of Railway Simply Supported Beam Bridge under Bidirectional Moving Loads." Advanced Materials Research 594-597 (November 2012): 1552–56. http://dx.doi.org/10.4028/www.scientific.net/amr.594-597.1552.

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In this thesis, the dynamic responses of simply supported beam bridge in a double-line railway under bidirectional moving loads are mainly studied. To study the characteristics of Euler- Bernoulli beam, a train is simplified as a series of concentrated forces with fixed wheelbase.Structural dynamics is used to deduce the analytical expressions of vertical vibration of simply supported beam under bidirectional moving loads. By simulation software MATLAB, the numerical result of the dynamic responses of simply supported beam bridge could be obtained. Then the 48 meters simply supported beam bridge in a high-speed railway is analyzed, the dynamic responses of simply supported beam of bidirectional moving loads with different interarrival times are discussed.Finally, some general laws for the design of double-line railway bridge are gained.

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Jin, Yu, Liu Yong, and Yang Weidong. "Dynamics research on actively controlled swashplateless rotor." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 233, no. 12 (January 13, 2019): 4492–508. http://dx.doi.org/10.1177/0954410018824474.

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This study presents the design, dynamic model, and dynamics research of a new cyclic pitch control strategy in motor-driven rotorcraft. In this strategy, the control response and flapping feature of conventional rotor systems can be obtained by imposing (1) a lag-pitch coupling on rotor blade and (2) an additional sinusoidal rotational speed of rotor shaft without any actuators or swashplate. This study establishes a refined nonlinear dynamic model including the effects of pitch motion, and figures out the fundamental dynamic characteristics of this novel configuration. Analyses of its mechanical stability, dynamic responses and stability in hover are also conducted. The model in this research, compared with the previous linear model, improves the predicting accuracies of dynamic responses remarkably. A preliminary understanding of this novel rotor's dynamic mechanisms is gained by this study.

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Liu, Xian Zeng, and Jun Zhang. "Dynamic Analysis of Helical Planetary Gear Train." Applied Mechanics and Materials 404 (September 2013): 312–17. http://dx.doi.org/10.4028/www.scientific.net/amm.404.312.

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A dynamic model for helical planetary gear train (HPGT) is proposed. Based on the model, the free vibration characteristics, steady-state dynamic responses and effects of design parameters on system dynamics are investigated through numerical simulations. The free vibration of the HGPT is classified into 3 categories. The classified vibration modes are demonstrated as axial translational and torsional mode (AT mode), radial translational and rotational mode (RR mode) and planet mode (P mode) followed by the characteristics of each category. The simulation results agree well with those of previous discrete model when neglecting the component flexibilities, which validates the correctness of the present dynamic model. The steady-state dynamic responses indicate that the dynamic meshing forces fluctuate about the average static values and the time-varying meshing stiffness is one of the major excitations of the system. The parametric sensitivity analysis shows that the impact of the central component bearing stiffness on the dynamic characteristic of the HPGT system is significant.

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Weng, Shun, Wei Tian, Hongping Zhu, Yong Xia, Fei Gao, Yaoting Zhang, and Jiajing Li. "Dynamic condensation approach to calculation of structural responses and response sensitivities." Mechanical Systems and Signal Processing 88 (May 2017): 302–17. http://dx.doi.org/10.1016/j.ymssp.2016.11.025.

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Bai, Zhengfeng, and Tianxi LIU. "A Study on Clearance Effects on Dynamic Responses of Robot Manipulator." Mechanics 27, no. 2 (April 15, 2021): 130–38. http://dx.doi.org/10.5755/j02.mech.26580.

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Clearances caused by assemblage, manufacturing errors and wear, affect inevitably the dynamic responses of mechanisms such as robot manipulator. In this study, the effects of clearance on a robot manipulator system are investigated numerically. The contact behavior along normal and tangential direction of clearance joint is described by a nonlinear contact force model and a modified Coulomb friction model respectively. Then, the dynamics equations of the robot manipulator system are established considering joint clearance. In order to investigate the effects of clearance on dynamic performances of practical mechanism, a planar robot manipulator system on a spacecraft system with a revolute clearance joint is used as the apply example. Four case studies for various clearance sizes are implemented to investigate and discuss the effects of joint clearance. The simulation results indicate that clearance joints have severe effects on the dynamic performances of mechanism system and the impact in clearance joints represented by contact force models must be considered in dynamics analysis and design of mechanism system. The simulation results in this work can predict the effects of clearance on robot manipulator system preferably and it is the basis of precision analysis, robust control system design of robot manipulator system.

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Gholizadeh, Majid, Iman Aghayan, and Farhad Hadadi. "Modeling Dynamic Frequency Response on Slab Track of Shinkansen Railway Based on Finite Element Method." Advances in Civil Engineering 2022 (February 14, 2022): 1–18. http://dx.doi.org/10.1155/2022/9574243.

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The use of slab tracks in lieu of ballast tracks has introduced new dimensions in track dynamics in high-speed railways. To improve the performance of slab tracks under dynamic frequency responses caused by loads on the Shinkansen railway, the present study aimed to investigate the effect of mechanical properties of track components, including the elasticity modulus and thickness on the resonance frequency of the vertical dynamic responses using the finite element method. Such responses included receptance and decay rate in the asphalt bearing layer (ABL), hydraulically bonded layer (HBL), and concrete bearing layer (CBL). In addition, the study sought to select the optimal layer as an effective layer in the view of reducing the resonance frequency of dynamic responses in comparison with the general model. Based on the data regarding the effects of elasticity modulus and thickness of slab track layers on the resonance of the dynamic frequency responses under the amplitude loads, by changing the load from 20 to 25 tons over the slab track, the receptance under the modulus and thickness change increased up to 34 and 29%. Moreover, the decay rate under the modulus and thickness change increased up to 31 and 37%. Accordingly, by increasing the load amplitude, the CBL and HBL showed lower dynamic responses than other layers. Thus, CBL and HBL were selected as the optimum layers for improving the performance of the slab track of the Shinkansen railway.

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Qin, W. J., and J. Q. He. "Optimum Design of Local Cam Profile of a Valve Train." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 224, no. 11 (May 14, 2010): 2487–92. http://dx.doi.org/10.1243/09544062jmes2116.

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In this paper, optimization of the local cam profile of a valve train modelled by a parameterized Bezier curve is described. Dynamic responses of the valve train are simulated through its multi-body system dynamics model built using ADAMS software. The kriging method is used to build the surrogate model, which presents the relationship between dynamic responses resulting from the multi-body system dynamics simulation and the parameters of the local Bezier profile. The local cam profile is optimized through a generic algorithm, such that the acceleration peak at the valve open phase is reduced significantly.

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Skadsem, Julie A. "Effect of Conductor Verbalization, Dynamic Markings, Conductor Gesture, and Choir Dynamic Level on Singers' Dynamic Responses." Journal of Research in Music Education 45, no. 4 (December 1997): 509–20. http://dx.doi.org/10.2307/3345419.

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The purpose of this study was to determine the effects of conductor verbalization, dynamic markings, conductor gesture, and choir dynamic level on individual singers' dynamic responses in music. Singers (N = 144) sang along with nine renditions of a tune while watching a videotape of a conductor, listening to a choir through headphones, and referring to the music. Instructions regarding the dynamic level (soft or loud) were given under four conditions: (a) verbal instructions, (b) written instructions, (c) changes in conducting gesture, and (d) volume changes in the choir. Results indicated that verbal instructions from the conductor elicited significantly stronger dynamic performance responses (alpha = .05) than did the other three instructional conditions. Singers responded significantly better on instructions pertaining to soft singing than they did on instructions relating to loud singing. Comparisons were made between conductors, college singers, and high school singers, and eye contact was also examined.

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Hei, Di, Yong Fang Zhang, Mei Ru Zheng, Liang Jia, and Yan Jun Lu. "Stability and Bifurcation of Nonlinear Bearing-Flexible Rotor System with a Single Disk." Advanced Materials Research 148-149 (October 2010): 141–46. http://dx.doi.org/10.4028/www.scientific.net/amr.148-149.141.

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Dynamic model and equation of a nonlinear flexible rotor-bearing system are established based on rotor dynamics. A local iteration method consisting of improved Wilson-θ method, predictor-corrector mechanism and Newton-Raphson method is proposed to calculate nonlinear dynamic responses. By the proposed method, the iterations are only executed on nonlinear degrees of freedom. The proposed method has higher efficiency than Runge-Kutta method, so the proposed method improves calculation efficiency and saves computing cost greatly. Taking the system parameter ‘s’ of flexible rotor as the control parameter, nonlinear dynamic responses of rotor system are obtained by the proposed method. The stability and bifurcation type of periodic responses are determined by Floquet theory and a Poincaré map. The numerical results reveal periodic, quasi-periodic, period-5, jump solutions of rich and complex nonlinear behaviors of the system.

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Zhao, Zhixin, Xin Li, Wenhua Wang, and Wei Shi. "Analysis of Dynamic Characteristics of an Ultra-Large Semi-Submersible Floating Wind Turbine." Journal of Marine Science and Engineering 7, no. 6 (June 1, 2019): 169. http://dx.doi.org/10.3390/jmse7060169.

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An initial design of the platform for the moderate water depth (100 m) is performed by upscaling of an existing 5 MW braceless semi-submersible platform design to support the DTU (Danish University of Science and Technology) 10 MW wind turbine. To investigate the dynamic characteristics of the ultra-large semi-submersible floating offshore wind turbine (FOWT), an aero-hydro-servo-elastic numerical modeling is applied to carry out the fully coupled time-domain simulation analysis. The motion responses of the ultra-large semi-submersible FOWT are presented and discussed for selected environmental conditions. Based on the quasi-static and dynamic analysis methods, the influence of the dynamic effects of the mooring lines on the platform motion responses and mooring line tension responses are discussed. Subsequently, the difference in the motion responses and structural dynamics of the DTU 10 MW and NREL (National Renewable Energy Laboratory) 5 MW FOWT is studied due to the difference in turbine properties. The simulation results reveal that the excitation of the low-frequency wind loads on the surge and pitch motions, the tower-base fore-aft bending moments and the mooring line tension response becomes more prominent when the size of the wind turbine increases, but the excitation action of the 3P effect on the structural dynamics of the 5 MW FOWT is more obvious than those of the 10 MW FOWT.

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Journal articles on the topic 'Dynamic responses'

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