3. Analysis of Harmonic Displacement Factors

2000 ◽  
pp. 61-88 ◽  
Author(s):  
R. T. Downs
Keyword(s):  
Harmonic Displacement

MEASUREMENT OF RELATIVE GROUND MOTION IN REFLECTION RECORDING

Geophysics ◽  
1938 ◽  
Vol 3 (1) ◽  
pp. 40-45 ◽  
Author(s):  
D. H. Gardner
Keyword(s):  
Ground Motion ◽  
Relative Sensitivity ◽  
Harmonic Displacement

A description of the method employed in determining the relative sensitivity of a reflection seismograph to harmonic displacement of [Formula: see text] inches is given. Results of comparing the sensitivity obtained at this level to the sensitivity used in reflection recording show a ground motion of [Formula: see text] inches for the deeper reflections. Comparisons are made between the sensitivities of the reflection seismograph and a mechanical seismograph taken at a level of [Formula: see text] inches.

scholarly journals Active Control of Rotor Vibrations by Means of Piezoelectric Actuators

2001 ◽  
Author(s):  
Costantino Carmignani ◽  
Paola Forte ◽  
Emiliano Rustighi
Keyword(s):  
Active Control ◽  
Piezoelectric Actuators ◽  
Mobile Bearing ◽  
Numerical Results ◽  
Hydrodynamic Bearing ◽  
Harmonic Displacement

Abstract This work deals with the development of an adaptive hydrodynamic bearing made of a mobile housing mounted on piezoelectric actuators. The device is placed near one of the two bearings supporting a slender shaft. Imposing a harmonic displacement on the mobile bearing, in two orthogonal directions, a rotating force, and hence a correcting moment, can be produced on the shaft so as to reduce the bending caused by the unbalance. The first tests carried out are encouraging and the agreement of experimental and numerical results is satisfactory.

Harmonic Displacement Excitation at a Support

1972 ◽  
Vol 14 (1) ◽  
pp. 1-3 ◽  
Author(s):  
R. E. D. Bishop
Keyword(s):  
Degrees Of Freedom ◽  
Linear Vibration ◽  
Simply Supported Beam ◽  
Simply Supported ◽  
Vibration Theory ◽  
General Terms ◽  
Distributed Parameters ◽  
Harmonic Displacement

The various uses to which receptances may be put in linear vibration theory are well known. For some purposes it would be useful to have the direct receptance at a co-ordinate expressed in terms of parameters of that modified system which is defined when the co-ordinate concerned is locked. The problem has been solved elsewhere (1) in general terms, for an undamped system with n degrees of freedom. The particular case of a simply supported beam is examined here, both for lumped and for continuously distributed parameters.

Pre-distorted sinewave-driven parallel-plate electrostatic actuator for harmonic displacement

2005 ◽  
Vol 15 (7) ◽  
pp. S103-S108 ◽  
Author(s):  
G de Graaf ◽  
L Mol ◽  
L A Rocha ◽  
E Cretu ◽  
R F Wolffenbuttel
Keyword(s):  
Parallel Plate ◽  
Electrostatic Actuator ◽  
Harmonic Displacement

scholarly journals Design of a Low-Frequency Harmonic Rotary Piezoelectric Actuator

Actuators ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 4
Author(s):  
Kang Liang ◽  
Chong Li ◽  
Yujian Tong ◽  
Jiwen Fang ◽  
Wei Zhong
Keyword(s):  
Piezoelectric Actuator ◽  
Harmonic Wave ◽  
Low Frequency ◽  
Experimental System ◽  
Piezoelectric Actuators ◽  
Driving Voltage ◽  
Driving Frequency ◽  
Output Characteristics ◽  
Driving Signal ◽  
Harmonic Displacement

Piezoelectric actuators usually operate under a high frequency driving signal. Here we report a harmonic rotating piezoelectric actuator by coupling a harmonic wave generator and a friction rotor, in which the actuator can be actuated by a low-frequency sinusoidal signal with positive bias. The harmonic wave is generated by a two-stage magnifying mechanism consisting of a displacement amplifier and a harmonic rod. Applying piezoelectricity theory, the actuator’s output characteristic equations are deduced. What is more, the output characteristics of piezoelectric actuators are tested with the established experimental system. Results show that the generated harmonic displacements can drive the actuator to work normally at a driving voltage of larger than 90 V and the maximum total harmonic displacement of the piezoelectric actuator comes up to 427.6 μm under the driving voltage of 150 V. Meanwhile, the error between the measured and calculated values of the harmonic displacement is less than 7%. Furthermore, the rotational speed of the piezoelectric actuator reaches 5.45 rpm/min at 150 V voltage and 5 Hz driving frequency.

On the Nonlinear Dynamics of a Vibro-Impacting Cantilever With End Mass

2012 ◽  
Author(s):  
Prasanna Gandhi ◽  
Ajinkya Badkas
Keyword(s):  
Nonlinear Dynamics ◽  
Dynamic Analysis ◽  
Frequency Response ◽  
Experimental Results ◽  
Response Curves ◽  
Close Match ◽  
Nonlinear Hysteresis ◽  
Fixed End ◽  
Stop Position ◽  
Harmonic Displacement

A theoretical and experimental dynamic analysis of a vibro-impacting cantilever with end mass is presented in this paper. The cantilever is excited by transverse harmonic displacement given at its fixed end with the help of a shaker. Nonlinearity in dynamics due to impact of cantilever on a motion limiting stop only on one side is considered. Experiments revealed quite interesting nonlinear hysteresis, jump, and drop phenomena in this case. Phenomena are experimentally characterized by varying the position and the gap between the stop and cantilever on a custom-built setup. Vibrating cantilever is modeled using assumed modes method while spring damper model for impacting stop is considered. Simulation and experimental results show close match for the same parameters under various cases of stop position and gap. Results are presented in terms of frequency response curves for range of parameters in non-dimensional form to enable their use in similar other cases.

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