Acoustic materials
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منابع مشابه
Investigation on acoustic behavior of acoustic porous absorbers to absorb sound energy and transmission loss index
In this study, the acoustic properties of porous absorbents with different porosity levels have been evaluated using different mathematical models. These models use one or more parameters of materials for calculating acoustic characteristics. In all of these models, materials are considered as equivalent fluid and reactionary characteristics have not been taken into account.
متن کاملEffect of porosity on the characteristics of underwater acoustic sound absorbers using theoretical models
Porous materials have good acoustic damping characteristics over a wide frequency range. As for sound waves, many small-scale pores in the coating materials can convert underwater-coating to rough surfaces. The main property of porous absorbents is their resistance against incident sound wave that leads to damping effect. From a physical point of view, damping occurs due to friction between flu...
متن کاملAcoustic Wave propagation through multilayer Thue-Morse structures containing two, three and four materials of Cu, Al, MgO and Pb
In this paper, the acoustic wave propagation in multilayer Thue-Morse structures has theoretically been studied. The composing layers were assumed do be Cu, Al, Mgo and Pb materials. Two, three or four different materials have been used in a typical structure. By using a perpendicular incident acoustic wave, the transmission coefficient was calculated and then by its old, the frequency gaps was...
متن کاملتضعیف امواج آکوستیک در Al 7075-T6 و St 304
Propagation and dispersion of acoustic waves is one of the important phenomena in physics. Acoustic-waves are nowadays widely used in a variety of applications ranging from underwater communications, identification and specification of the internal defects of materials to extracorporeal shock wave lithotripsy. Apart from application and utilization of such phenomena, study on production and pro...
متن کاملبررسی کوپلینگ پیزوالکتریکی و آنیزتروپی بر انتشار امواج صوتی در بلوره صوتی لیتیوم نیوباته
The acoustic wave velocity depends on elasticity and density at most materials, but because of anisotropy and especially piezoelectric coupling effect, the acoustic wave propagation at piezoelectric based crystalloacoustic materials, is an applied and challenging problem. In this paper, using modified Christoffel's equation based on group velocity concept, the effect of anisotropy and piezoelec...
متن کاملStudy on FRP composite materials’ damage based on the acoustic emission testing technology
Study the tensile damage and fracture behavior of FRP composite materials by the acoustic emission technology, broadband sensors record the acoustic emission signals when composite materials in the process of tensile damage at different fiber angle. The acoustic emission characteristics of FRP composite materials’ tensile damage was analyzed by 3D parameter methods. Analysis the amplitude of co...
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