Virtual sensors for active noise control in acoustic–structural coupled enclosures using structural sensing: robust virtual sensor design

The work was aimed to develop a robust virtual sensing design methodology for sensing and active control applications of vibro-acoustic systems. The proposed virtual sensor was designed to estimate a broadband acoustic interior sound pressure using structural sensors, with robustness against certain dynamic uncertainties occurring in an acoustic–structural coupled enclosure. A convex combination of Kalman sub-filters was used during the design, accommodating different sets of perturbed dynamic model of the vibro-acoustic enclosure. A minimax optimization problem was set up to determine an optimal convex combination of Kalman sub-filters, ensuring an optimal worst-case vir- tual sensing performance. The virtual sensing and active noise control performance was numerically investigated on a rectangular panel-cavity system. It was demonstrated that the proposed virtual sen- sor could accurately estimate the interior sound pressure, particularly the one dominated by cavity- controlled modes, by using a structural sensor. With such a virtual sensing technique, effective active noise control performance was also obtained even for the worst-case dynamics

Vibration absorption performance of membrane-type metamaterial on a thin plate

This work aims to investigate the vibration absorption performance of membrane-type metamaterial on a thin plate. Simulation work was conducted on membrane-type metamaterial using membrane resonators with various configurations of decorated masses. The bandgap property of membrane-type metamaterial with multiple masses was investigated. It was found that a slight adjustment of location for the decorated masses could result in a 45 Hz change of the membrane-type metamaterial bandgap location. Through the simulation work, the vibration transmissibility of a thin plate attached with membrane resonators was studied and it was showed that this membrane-type resonator could effectively suppress the vibration of a thin plate

Prediction of bandgaps in membrane-type metamaterial attached to a thin plate

This work proposes an analytical method to analyse the bandgap location and width of membrane-type metamaterial when it is attached to a thin plate structure. This method enables the bandgap prediction of such a structure by adjusting the tensile stress of the membrane directly. The accuracy of the model is verified by constructing a finite structure model for numerical simulation and comparing the results. It shows that the results given by the analytical model are primarily consistent with the simulation. The effect of membrane tensile stress and attached mass on the bandgap location and width is also investigated. It is found that the width of bandgap can be increased by increasing the membrane tensile stress and using a heavier mass attached to the membrane

Study of HEV power management control strategy based on driving pattern recognition

In this work, an optimized HEV power management fuzzy control strategy is proposed with the aim to further improve the fuel efficiency of the rule-based control strategy and overcome the drawbacks of the conventional control strategies. The driving pattern recognition method is used to classify the driving condition into one of the driving patterns to select proper control algorithm. The dynamic programming solution is used to design the fuzzy control strategies for each driving pattern. The simulation results indicate that by adopting the proposed strategy the fuel efficiency of HEV is improved, especially under complex driving conditions

Forced vibration analysis of a fibre-reinforced polymer laminated beam using the green function method

This work aims to study forced vibration characteristics of Fibre-Reinforced Polymer (FRP) composite laminated beam with different properties, through a development of an analytical model using the Green function method. The forced vibration characteristics of a FRP laminated beam structure is generally more complex than those of a homogeneous beam structure since each layer is anisotropic with a different layer having different properties. In this work, the Green function method is used to model an FRP laminated beam to solve the associated equation of motion. The proposed analytical model allows a more efficient parametric analysis to be done on FRP laminated beams, in contrast to using a numerical model that is more computationally expensive. The analytical model is verified through a comparison with the numerical model of FRP laminated beam. Based on the developed model, a FRP laminated beam with various fibre orientations, is studied under forced vibration, demonstrating the effectiveness of the proposed method for forced vibration analysis of a laminated beam

Forced vibration analysis of a fibre-reinforced polymer laminated beam using the green function method

This work aims to study forced vibration characteristics of Fibre-Reinforced Polymer (FRP) composite laminated beam with different properties, through a development of an analytical model using the Green function method. The forced vibration characteristics of a FRP laminated beam structure is generally more complex than those of a homogeneous beam structure since each layer is anisotropic with a different layer having different properties. In this work, the Green function method is used to model an FRP laminated beam to solve the associated equation of motion. The proposed analytical model allows a more efficient parametric analysis to be done on FRP laminated beams, in contrast to using a numerical model that is more computationally expensive. The analytical model is verified through a comparison with the numerical model of FRP laminated beam. Based on the developed model, a FRP laminated beam with various fibre orientations, is studied under forced vibration, demonstrating the effectiveness of the proposed method for forced vibration analysis of a laminated beam

Vibration sensor placement for delamination detection in a beam structure based on the vibration-based chaotic oscillator method

This work aims to study the effect of sensor placement for delamination damage detection in a beam structure using a vibration-based chaotic oscillator method. A chaotic oscillator method is used due to its sensitivity to relatively small changes in measured vibration signal. The effect of vibration sensor placement to the delamination detection sensitivity for various delamination sizes is investigated. The Lyapunov Exponent (LE) is used in conjunction with the chaotic oscillator as a damage index to describe the extent of delamination damage in the laminated beam. The relationship between the damage index and sensor placement for different delamination size is studied to analyse the effect of sensor placement on detection performance. It is found that the sensor placement has a significant influence on the sensitivity of delamination detection with different delamination size

Prediction of bandgaps in membrane-type metamaterial attached to a thin plate

This work proposes an analytical method to analyse the bandgap location and width of membrane-type metamaterial when it is attached to a thin plate structure. This method enables the bandgap prediction of such a structure by adjusting the tensile stress of the membrane directly. The accuracy of the model is verified by constructing a finite structure model for numerical simulation and comparing the results. It shows that the results given by the analytical model are primarily consistent with the simulation. The effect of membrane tensile stress and attached mass on the bandgap location and width is also investigated. It is found that the width of bandgap can be increased by increasing the membrane tensile stress and using a heavier mass attached to the membrane