Structure-Borne Power Transmission in Thin Naturally Orthotropic Plates: General Case

2003 ◽  
Vol 9 (10) ◽  
pp. 1189-1199 ◽  
Author(s):  
Nirmal Kumar Mandal ◽  
Roslan Abd. Rahman ◽  
M. Salman Leong

The structural intensity technique is usually used to estimate vibration power flow in structures. This method is used to determine vibration power flow in thin naturally orthotropic plates. The bending wave is considered to find general vibration power transmission in the frequency domain that is not approximated by far field conditions. This intensity formulation defines power flow per unit width of the plates (W m−1) similar to that of the conventional idea. Power flow estimation is formulated using cross-spectra of field signals, facilitating the use of a fast Fourier transform analyzer.

2002 ◽  
Vol 8 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Nirmal Kumar Mandal ◽  
M. Salman Leong ◽  
R. Abd. Rahman

Structural intensity method is used to formulate vibration power flow model in naturally orthotropic plates in the frequency domain for far-field conditions considering bending waves. Dimensionless parameters are used in classical orthotropic plate equations to get this power. Techniques of Fourier transform and finite difference approximation are used in the formulation. Shear force components of vibration power transmission in x-direction and y-direction are obtained separately. Total power is obtained from the idea of far-field conditions. Cross-spectral density functions of field signal are used to facilitate the estimation of power transmission. Structural intensity is formulated, which is similar to that of the conventional two-transducer method. A transducer array of two points is required to get an intensity vector in one direction of a point in the plates. A new bending wave number and a modified Laplace operator are also proposed.


2008 ◽  
Vol 15 (1) ◽  
pp. 71-78
Author(s):  
Nirmal K. Mandal

The structural intensity (SI) technique is an essential tool for locating and ranking vibration sources and sinks on structures. It can quantify vibration fields by plotting a vector map of energy transmission on the structures. In this paper, a different strategy, changing coordinate systems of plate equations, is used to develop an intensity equation from shear force components in both x and y directions. The formulation is carried out in the frequency domain considering flexural waves. Orthotropic plate theory, far-field conditions, Fourier transform, and finite difference approximation are considered. The same intensity definition is obtained using this different strategy. A dual-channel FFT analyser is essential for data acquisition to get an intensity vector in a particular direction for far-field conditions.


2014 ◽  
Vol 9 (9th) ◽  
pp. 1-16
Author(s):  
Heba Allah Ahmed ◽  
T. Abdel Salam ◽  
M. Mostafa ◽  
M. Badr

2003 ◽  
Vol 264 (1) ◽  
pp. 203-224 ◽  
Author(s):  
D.-H. Park ◽  
S.-Y. Hong ◽  
H.-G. Kil

2013 ◽  
Vol 694-697 ◽  
pp. 316-320
Author(s):  
Xiang Jun Kong ◽  
Er Ming Song ◽  
Chang Zheng Chen

Isolation system of the heat water pumps can be simplified as a double sources exciting and double output double-deck vibration isolation system model, expressions of transmitted power flow and vibration speed to the basement are deduced based on the double sources exciting and double output double-deck vibration isolation system electric-force(E-F) analog picture, the curves of power flow and vibration speed transmitted to basement how the upper deck vibration isolation and intermediate mass effect are drawn by using mat lab program. The results show that the adjusting the upper deck vibration isolation stiffness parameters has little effect on the amplitude of vibration power flow, increasing intermediate mass can move first peak to the low frequency, increasing intermediate mass can obviously reduce t transmitted power flow and transmitted vibration speed amplitude to the basement.


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