scholarly journals The Relationship between Structural Intensity and Sound Field Characteristics of Cylindrical Shells

2017 ◽  
Vol 214 ◽  
pp. 41-49 ◽  
Author(s):  
Yuran Wang ◽  
Rong Huang ◽  
Zishun Liu
Keyword(s):  
Cylindrical Shells ◽  
Sound Field ◽  
Structural Intensity ◽  
The Relationship

scholarly journals Dynamic behaviors of cylindrical shells with geometric imperfection

2019 ◽  
Vol 293 ◽  
pp. 01003
Author(s):  
J F Jia ◽  
A D Lai ◽  
D L Rong ◽  
Z H Zhou ◽  
X S Xu
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Cylindrical Shells ◽  
Vibrational Modes ◽  
Engineering Structures ◽  
Geometric Imperfections ◽  
Geometric Imperfection ◽  
Local Vibrational Modes ◽  
The Relationship

For finding out the relationship between vibrational modes and geometric imperfections, the dynamic behavior of cylindrical shells with a local imperfection is analyzed by using numerical simulation of finite element method in this paper. The results show that there are some differences in vibrational modes between cylindrical shells with and without imperfections. They appear that main corrugation of the mode of the higher orders for the shell with a local imperfection can be fastened on the region of the imperfection but the low order ones. The results also show that the vibrational modes of shells depend upon the size, shape and location of the imperfections. The local vibrational modes are discovered and are more obvious for the imperfection of the larger size. These results are helpful to the design of engineering structures.

Acoustic Startles in Horror Films

Projections ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 45-66
Author(s):  
Valerio Sbravatti
Keyword(s):  
Crucial Role ◽  
Psychological Factors ◽  
Startle Response ◽  
Acoustic Startle ◽  
Sound Field ◽  
Horror Films ◽  
The Relationship

The acoustic blast is one of the most recurrent sound devices in horror cinema. It is designed to elicit the startle response from the audience, and thus gives them a “jump scare.” It can occur both in the form of a diegetic bang and in the form of a nondiegetic stinger (i.e., a musical blare provided by the score). In this article, I will advance the hypothesis that silence plays a crucial role in contemporary horror films, both perceptually, since it leaves the sound field free for the acoustic blast, and cognitively, since it posits the audience in an aversive anticipatory state that makes the startle more intense. I will analyze the acoustic startle using a neurofilmological approach, which takes into account findings from experimental sciences in order to better understand the relationship between physiological and psychological factors that make such an effect possible during the filmic experience.

scholarly journals Underwater Spiral Wave Sound Source Based on Phased Array with Three Transducers

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3192
Author(s):  
Lu ◽  
Guo ◽  
Lan ◽  
Sun ◽  
Li ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Sound Source ◽  
Piezoelectric Ceramic ◽  
Phased Array ◽  
Fem Simulation ◽  
Spiral Wave ◽  
Sound Field ◽  
The Finite Element Method ◽  
The Relationship ◽  
Made In

This paper realizes an underwater spiral wave sound source by using three omni-directional spherical transducers with three different phases. The pressure distribution of the sound field for a phased array is derived using the superposition theory of sound field. The generation of spiral wave field is presented, the relationship between the performance of phased array sound field and the array parameters is analyzed, and also verified by the finite element method (FEM). A spiral wave sound source with three spherical piezoelectric ceramic transducers is then designed and fabricated based on FEM simulation, and the performance of the sound source is analyzed. Measurements are made in a reverberation pool, and the result shows that the fabricated spiral wave sound source is capable of producing a spiral sound wave. Under a frequency of 3.5 kHz, the phase directivity has a fluctuation of ±21°, and the amplitude directivity range is 4.3 dB, which verifies the realization of the spiral wave sound source.

Characteristics of Modal Sound Radiation of Finite Cylindrical Shells

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Tian Ran Lin ◽  
Chris Mechefske ◽  
Peter O’Shea
Keyword(s):  
Cylindrical Shells ◽  
Low Frequency ◽  
Sound Radiation ◽  
Sound Field ◽  
Radiation Efficiency ◽  
Boundary Element Methods ◽  
Frequency Range ◽  
Nodal Lines ◽  
Infinite Cylindrical Shell ◽  
Modal Index

Characteristics of modal sound radiation of finite cylindrical shells are studied using finite element and boundary element methods in this paper. In the low frequency range, modal radiation efficiencies of finite cylindrical shells are found to asymptotically approach those of the corresponding infinite cylindrical shell when structural trace wavelengths of the cylindrical shells are greater than the acoustic wavelength. Modal radiation efficiencies for each group of modes having the same circumferential modal index decrease as the axial modal index increases. They converge to each other when the axial trace wavelength is much greater than the circumferential trace wavelength. The mechanism leading to lower radiation efficiency of modes with higher circumferential modal index of short cylinders is explained. Similar to those of flat plate panels, change in slope or waviness is observed in modal radiation efficiency curves of modes with higher order axial modal index at medium frequencies. This is attributed to the interference of sound radiated by neighboring vibrating cells when the distance between nodal lines of a vibrating mode is in the same order or smaller than the acoustic wavelength. The effects of the internal sound field on modal radiation efficiencies of a finite open-end cylinder are discussed.

A Consideration on Acoustic Properties on Concert-Hall Stages

2011 ◽  
Vol 18 (3-4) ◽  
pp. 221-235
Author(s):  
Kanako Ueno ◽  
Hideki Tachibana
Keyword(s):  
Future Study ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Sound Field ◽  
Acoustic Properties ◽  
Concert Hall ◽  
Field Simulation ◽  
Experimental Findings ◽  
Acoustic Conditions ◽  
The Relationship

This paper discusses acoustic properties that musicians experience on a concert hall stage; the discussion is based on the authors' experience gained from conducting experimental studies using a three-dimensional sound field simulation technique. First, the experimental findings on the relationship between the acoustic requirements of musicians and acoustic conditions such as early reflection and reverberation are reviewed. Second, the validity and problems of stage acoustic indices STearly, STlate, and EEL are addressed. In addition, unsolved issues with regard to musicians' requirements during their performance are considered and problems requiring future study are pointed out.

Investigation of Electric Discharge Sound in Atmospheric Pressure Plasma Using Optical Wave Microphone

2011 ◽  
Vol 14 (1) ◽  
Author(s):  
Toshiyuki Nakamiya ◽  
Yoichiro Iwasaki ◽  
Fumiaki Mitsugi ◽  
Ryosuke Kozai ◽  
Tomoaki Ikegami ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Sound Field ◽  
Atmospheric Pressure Plasma ◽  
Acoustic Properties ◽  
Electric Discharges ◽  
Lens System ◽  
Beam Path ◽  
Optical Lens ◽  
Optical Wave ◽  
The Relationship

AbstractThe light diffraction technique, which we call the “Optical Wave Microphone (OWM)” technique, is an effective sensing method to detect the sound and is flexible for practical uses as it involves only a simple optical lens system. This technique is also very useful to detect the sound wave without disturbing the sound field. Moreover, OWM can be used for sound field visualization by computerized tomography (CT) because the ultrasmall modulation by the sound field is integrated along the laser beam path. The characteristics of the coplanar DBD (Dielectric Barrier Discharge) operated in air is investigated. Applied voltage, current and the electrical discharge sound of coplanar DBD are measured, and examined the relationship between the micro discharge and the acoustic properties. We expect that understanding of acoustic properties gives more details of electric discharges. These are the first experiments to verify the feasibility of the OWM-CT method for the visualization of the sound field of DBD discharge.

Dynamic Buckling of Elastic Cylindrical Shells under Axial Step Load

2015 ◽  
Vol 751 ◽  
pp. 182-188
Author(s):  
Jia Qun Wang ◽  
Zhi Jun Han ◽  
Guo Yun Lu
Keyword(s):  
Critical Load ◽  
Cylindrical Shells ◽  
Ritz Method ◽  
Coefficient Matrix ◽  
Dynamic Buckling ◽  
Governing Equations ◽  
Space Technique ◽  
Circular Cylindrical Shells ◽  
The Relationship ◽  
Axial Waves

Considering the effect of stress wave, the dynamic buckling of circular cylindrical shells under an axial step load is discussed using the classical shell theories and the state-space technique in the paper. Based on the Hamilton’s principle, the dynamic buckling governing equations of shells are derived and solved with the Rayleigh-Ritz method. If the linear homogeneous equations have a non-trivial solution, the determinant of the coefficient matrix must be equal to zero, so the expression of the critical load on the dynamic buckling is got. The relationship between the critical load and length is obtained by using MATLAB software. The influences of boundary conditions, thickness, the number of circumferential waves and the number of axial waves on the dynamic buckling loads are discussed based on numerical computation.

The Research about the Vibroacoustic Characteristics of the Surface Cracked Plate

2014 ◽  
Vol 602-605 ◽  
pp. 303-310
Author(s):  
Gui Jie Liu ◽  
Meng Meng Li ◽  
Yu Qian Wang ◽  
Yu Zhan Yuan
Keyword(s):  
Theoretical Formula ◽  
Spring Model ◽  
Cracked Plate ◽  
Structural Intensity ◽  
Line Spring Model ◽  
Simulation Results ◽  
Shell Finite Element ◽  
Vibration Parameters ◽  
Relationship Of ◽  
The Relationship

Vibration characteristics of surface cracked plate are studied from the view of structural intensity .Line-spring model of the surface crack is put forward based on fracture mechanics. The relationship of the additional angle and displacement with the crack parameters is derived. The concept of additional structural intensity is presented and the additional structural intensity’s expression of shell finite element is deduced. The change regulars between structural intensity and vibration parameters with crack’s parameters are concluded by using ANSYS and MATLAB software, the simulation results are matched with the trend of theoretical formula.

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