چكيده به لاتين
Vibration control is a critical issue in many engineering systems such as automobile, machining, construction, ship-building, aerospace industries. The purpose of this study is to control and survey of propagated sound in an intelligent cylindrical shell using electrosurgical fluid and piezoelectric patches. In the present thesis, for modeling the problem and obtaining the governing equations on the system, the Sanders theory for the cylindrical shell and the first-order Kelvin- Voigt viscoelastic model for Electrorheological fluid has been used. In this study by using the vibrational modes in the Kirchhoff-Helmholtz integral and the modal acoustic estimation method, the propagated sound in the environment is estimated. First, the governing equations of the system by using the assumed modes method for a three-layer cylindrical shell with an electrorheological fluid core are obtained. Comparing the results of the frequencies and the Frequency Response Function diagram with the previous works, indicates the high accuracy of modeling which is done. Then, the equations are represented in the form of the state space and using the modal acoustic estimation method, the propagated sound in the cylindrical shell is estimated. The active control of sliding mode is used to reduce the propagated sound in the cylindrical shell and the results obtained from the designed controller indicate the effectiveness of the controller in reducing the propagated sound.
