• Steel and Composite Structures
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• v.50 no.3
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• pp.299-318
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• 2024

The main objective of this paper is to compute the far-field acoustic radiation (sound radiation) of functionally graded plates (FGM) loaded by sinusoidally varying point load subjected to the arbitrary boundary condition is carried out. The governing differential equations for thin functionally graded plates (FGM) are derived using classical plate theory (CPT) and Rayleigh integral using the elemental radiator approach. Four cases, segregated on power-law index k=0,1,5,10, are studied. A novel approach is illustrated to compute sound fields of vibrating FGM plates using the physical neutral surface with an elemental radiator approach. The material properties of the FGM plate for all cases are calculated considering the power law indexes. An in-house MATLAB code is written to compute the natural frequencies, normal surface velocities, and sound radiation fields are analytically calculated using semi-analytical formulation. Ansys is used to validate the computed sound power level. The parametric effects of the power law index, modulus ratios, different constituent of FGM plates, boundary conditions, damping loss factor on the sound power level, and radiation efficiency is illustrated. This work is the benchmark approach that clearly explains how to calculate acoustic fields using a solid layered FGM model in ANSYS ACT. It shows that it is possible to asymptotically stabilize the structure by controlling the intermittent layers' stiffness. It is found that sound fields radiated by the elemental radiators approach in MATLAB, ANSYS and literatures are in good agreement. The main novelty of this research is that the FGM plate is analyzed in the low-frequency range, where the stiffness-controlled region governs the whole analysis. It is concluded that a clamped mono-ceramic FGM plate radiates a lesser sound power level and higher radiation efficiency than a mono-metallic or metal-rich FGM plate due to higher stiffness. It is found that change in damping loss factor does not affect the same constituents of FGM plates but has significant effects on the different constituents of FGM plates.

• Proceedings of the Korea Contents Association Conference
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• 2004.05a
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• pp.553-561
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• 2004

It works as intermediation of communication of publics these days. Since 20 century, We, Koreans, have established new chaotic multi culture with traditional Korean culture and other different culture from everywhere. Meanwhile, we occupied the most powerful semi-conduct and IT indusry. Within those circumstance, people feel very confused in political, cultural and social aspect. The society armed with economy and popularization promotes material satisfaction with this potential possibility of anonymous masses. However, it results to cause loneliness, isolation, alienation, anonymity, non individuality and commodity of culture. In my work, such phenomenon reveals through human character in a city. People are exposed culture of consumption and surrounded and tempted by all those artificial and superficial atmosphere. Human are possessed and exposed to attractive products and visual images. Finally they make themselves stuck in their case of this world. People lose their own identify and shape of bodies. That is our portrait, who are living this moment. Also, this is a symbol that destroys this modern society. As a result, 1 consider such aspects through those elements above to think how to keep and rethink our identity and what to do for this world.