بررسی افت انتقال صوت و فشار صوتی پوسته دو انحنایی با استفاده از تئوری لایه گون

Plates and doubly curved composite shells are widely used in different industries such as aviation, turbine manufacturing, sound insulation, automobile manufacturing, etc. due to their high ratio of mechanical strength to weight. The acoustic and dynamic performance of composite structures depends on characteristics of the materials, stacking sequence and the geometrical dimensions. In composite structures, due to the layers that exist in laminates and have discontinuity in mechanical properties, a composite structure experiences stress concentration, which can lead to matrix failure and delamination. It should be understood that single-layer theories such as shear deformation theories are not capable of calculating such stresses. Also, noise reduction is very important in different industries. when composite structures are used as primary or main structures, the purpose of analyzing these structures should be to accurately evaluate the overall behavior of the structure, such as interlaminar stresses, natural frequency, and performance of each layer separately. Considering the thickness of the primary structures, single-layer theories are not a suitable solution for modeling of composite structures. Therefore, the analysis of primary composite structures requires using a layerwise theory. Therefore, in this research, the analysis of sound transmission loss and sound pressure of a doubly-curved shell is studied using layerwise theory. First, the governing equations are derived using Hamilton's principle, and then a computer program is developed using MATLAB software, and the results are verified with available results of researchers. In this study, the sound transmission loss in doubly curved shell is investigated. The results of this research show that the use of doubly-curved structure in low frequencies increases the sound transmission loss. Also, by increasing the radius of curvature, the frequency of curvature occurs in a lower range, but it has no effect on the coincidence frequency. Finally effects of incident angle, radius of curvature and sound pressure are studied.