Sharif Digital Repository

The developing of technology has discovered new materials which have been applied to improve the performance of structures. The researchers have recently increased the attention in controllable fluids and its applications. Magnetorheological (MR) dampers are devices that employ rheological fluids to modify their mechanical properties. Their mechanical simplicity, high dynamic range, lower power requirements, large force capacity, robustness and safe manner operation in case of fail have made them attractive devices to passive, semi-active and active control in mechatronic, civil, aerospace and automotive applications. The characteristics of the MR damper change when the rheological fluid is... 

Supersonic aeroelastic instability of a three-layered sandwich beam of rectangular cross section with an adaptive magneto-rheological fluid (MRF) core layer is investigated. The panel is excited by an airflow along it's longitudinal direction. The problem formulation is based on classical beam theory for the face layers, magnetic field dependent complex modulus approach for viscoelastic material model and the linear first-order piston theory for aerodynamic pressure. The classical Hamilton's principle and the assumed mode method are used to set up the equations of motion. The validity of the derived formulation is confirmed through comparison with the available results in the literature. The... 

Laminated composite structures are widely being used in modern industries particularly robot arms, aerospace and wind turbine blades where the structures mainly exposed to harsh random vibration and in turn, leads to unpredicted failure. Adding Magneto-rheological (MR) fluids in such structures may significantly improve their dynamic response. In the present work, the vibration response of laminated composite beams filled with MR fluids (MR laminated beam) under random loading has been investigated using experimental as well as simulation approaches. Finite Element Model (FEM) has been utilized to simulate the vibration response under random loading. An in-house set-up has been designed to... 

This study considers the aeroelastic instability of a partially treated magneto-rheological fluid sandwich panel in supersonic airflow. The linear first-order piston theory is used for modeling the aerodynamic pressure. Using classical Hamilton’s principle along with the finite element method, the equations of motion are derived. The critical value of the non-dimensional aerodynamic pressure is obtained by traditional p-method scheme. The validity of the finite element formulation is examined through comparison with those obtained from the assumed mode formulation and the available results in the literature. Various parametric studies including the effects of applied magnetic field, core and... 

This study considers the aeroelastic instability of a partially treated magneto-rheological fluid sandwich panel in supersonic airflow. The linear first-order piston theory is used for modeling the aerodynamic pressure. Using classical Hamilton’s principle along with the finite element method, the equations of motion are derived. The critical value of the non-dimensional aerodynamic pressure is obtained by traditional p-method scheme. The validity of the finite element formulation is examined through comparison with those obtained from the assumed mode formulation and the available results in the literature. Various parametric studies including the effects of applied magnetic field, core and...