Effect of Hygrothermal Load on Amplitude Frequency Response for CFRP Spherical Shell Panel

2021 ◽  
pp. 114978
Author(s):  
Hong Tang ◽  
Hong-Liang Dai ◽  
Yi Du
Keyword(s):  
Spherical Shell ◽  
Frequency Response ◽  
Amplitude Frequency Response ◽  
Shell Panel

Vibration Analysis of Diesel’s Undercarriage by Virtual Measure and Actual Measure

2011 ◽  
Vol 228-229 ◽  
pp. 621-626
Author(s):  
Peng Liu ◽  
Ying Yun Huang ◽  
Hao Peng Gao ◽  
Da Sheng Ou
Keyword(s):  
Frequency Response ◽  
Time Domain ◽  
Vibration Analysis ◽  
Response Characteristics ◽  
Amplitude Frequency Response ◽  
Actual Measure ◽  
Frequency Response Characteristics ◽  
The Difference

This paper proposes to verify and test the vibration of diesel’s undercarriage got by virtual measure and actual measure through the analysis of time domain characteristics and amplitude frequency response characteristics of three-orientation vibrant speed of diesel’s undercarriage, represents the difference in time domain characteristics and amplitude frequency response characteristics got by virtual measure and actual measure, expounds the reasons of difference and puts forward a method to diminution the difference. It proves that virtual measure can replace actual measure in a way, though there are some difference in existence, we can erase these difference to the best of ours’ abilities through enough analysis.

DESIGN OF -1/2n ORDER ANALOG FRACTANCE APPROXIMATION CIRCUIT USING CONTINUED FRACTIONS DECOMPOSITION

2012 ◽  
Vol 21 (04) ◽  
pp. 1250035 ◽  
Author(s):  
YAN LIU ◽  
YI-FEI PU ◽  
JI-LIU ZHOU ◽  
XIAO-DONG SHEN
Keyword(s):  
Fractional Calculus ◽  
Frequency Response ◽  
Experimental Evidence ◽  
Continued Fractions ◽  
Continued Fraction ◽  
Analog Circuit ◽  
Synthesis Method ◽  
Network Synthesis ◽  
Network Function ◽  
Amplitude Frequency Response

In order to solve the most important problem of the fractional calculus (FC) application, the realization of analog circuit of fractance, continued fraction theory is applied to design the -1/2n order analog fractance approximation circuit. The author presents a network function of ideal fractance and decomposes it in continued fractions (CFs) form to obtain the corresponding analog fractance approximation circuit. The new circuit consists of ordinary passive RC component through network synthesis method. Simulations are performed for the verification of the new circuit. Experimental evidence has proved that the performance of novel -1/2n order analog fractance approximation circuit is good in both amplitude-frequency response and phase-frequency response.

Two types of scale effects on the nonlinear forced vibration of axially moving nanobeams

2020 ◽  
Vol 34 (10) ◽  
pp. 2050095
Author(s):  
Jing Wang ◽  
Jianqiang Sun
Keyword(s):  
Mechanical Properties ◽  
Frequency Response ◽  
Continuum Mechanics ◽  
Forced Vibration ◽  
Characteristic Length ◽  
Scale Effects ◽  
Material Characteristic ◽  
Main Resonance ◽  
Amplitude Frequency Response ◽  
Axially Moving

Various non-classical continuum mechanics models appearing in previous studies cannot perfectly explain the mechanical properties of micro- and nanomaterials. Establishing a reasonable continuum mechanics model that comprehensively reflects the scale effect on material deformation is of great practical significance for objectively explaining the variation law of mechanical properties of micro- and nanomaterials under the combined action of different scale effects. Based on nonlocal strain gradient theory, a new scale-dependent model is proposed for axially moving nanobeams. In this study, an asymptotic expansion is performed using the multiscale time method to obtain the amplitude-frequency response curve of the equilibrium solutions for the forced vibration problem. Afterwards, the effects of various system parameters, especially the scale parameters, on the resonance curve are examined. Finally, the effects of nonlocal parameters and material characteristic length parameters on the amplitude-frequency response curves are investigated through typical numerical examples. The numerical results show that the nonlocal parameters promote the emergence of the main resonance, whereas the material characteristic length parameters suppress the emergence of the main resonance. Moreover, these parameters also affect the response amplitude and the skewness and jumping point of the amplitude-frequency characteristic curve.

scholarly journals Impulse Noise: Can Hitting a Softball Harm Your Hearing?

2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
Korrine Cook ◽  
Samuel R. Atcherson
Keyword(s):  
Spectral Analysis ◽  
Frequency Response ◽  
Sound Pressure Level ◽  
Impulse Noise ◽  
Sound Pressure ◽  
Pressure Level ◽  
Noise Floor ◽  
Playing Field ◽  
Multiple Exposures ◽  
Amplitude Frequency Response

The purpose of this study is to identify whether or not different materials of softball bats (wooden, aluminum, and composite) are a potential risk harm to hearing when batting players strike a 12′′ core .40 softball during slow, underhand pitch typical of recreational games. Peak sound pressure level measurements and spectral analyses were conducted for three controlled softball pitches to a batting participant using each of the different bat materials in an unused outdoor playing field with regulation distances between the pitcher’s mound and batter’s box. The results revealed that highest recorded peak sound pressure level was recorded from the aluminum (124.6 dBC) bat followed by the composite (121.2 dBC) and wooden (120.0 dBC) bats. Spectral analysis revealed composite and wooden bats with similar broadly distributed amplitude-frequency response. The aluminum bat also produced a broadly distributed amplitude-frequency response, but there were also two very distinct peaks at around 1700 Hz and 2260 Hz above the noise floor that produced its ringing (or ping) sound after being struck. Impulse (transient) sounds less than 140 dBC may permit multiple exposures, and softball bats used in a recreational slow pitch may pose little to no risk to hearing.

Bio-MEMS Circular Plate Sensors Under Electrostatic Hard Excitations: Frequency Response of Superharmonic Resonance of Fourth Order

2020 ◽  
Author(s):  
Julio Beatriz ◽  
Dumitru I. Caruntu
Keyword(s):  
Frequency Response ◽  
Circular Plate ◽  
Fourth Order ◽  
Multiple Scales ◽  
Superharmonic Resonance ◽  
Electrostatically Actuated ◽  
Amplitude Frequency Response ◽  
Elastic Circular Plate ◽  
Modes Of Vibration ◽  
The Difference

Abstract This paper investigates the frequency-amplitude response of electrostatically actuated Bio-MEMS clamped circular plates under superharmonic resonance of fourth order. The system consists of an elastic circular plate parallel to a ground plate. An AC voltage between the two plates will lead to vibrations of the elastic plate. Method of Multiple Scales, and Reduced Order Model with two modes of vibration are the two methods used in this work. The two methods show similar amplitude-frequency response, with an agreement in the low amplitudes. The difference between the two methods can be seen for larger amplitudes. The effects of voltage and damping on the amplitude-frequency response are reported. The steady-state amplitudes in the resonant zone increase with the increase of voltage and with the decrease of damping.

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