Optimal Actuator Location And Active Vibration Control Of Smart Constrained Layer Damping Plate

With fuel economy have become increasingly demanding, lightweight body is particularly important. In the process of lightweight car body, the body panels thinning results in the decrease of car body stiffness, increasing the body structure of low frequency vibration and noise, it is conflict with automobile comfort requirements, the traditional NVH technology is no longer a good solution to these problems. Smart Constrained Layer Damping(SCLD) combined with the advantages of passive damping technology and active control technology, which can control the vibration of the body effectively in a very wide frequency range, especially at low frequency. It provides a new approach of low frequency vibration control and NVH optimization for car body.In this paper, a clamped-clamped plate partly treated with SCLD structure is investigated. First, the system dynamics model is established based on finite method and the characteristics of viscoelastic materials varying with temperature and frequency are described by GHM damping model. The controllable and observable control model is obtained by using dynamic condensation method and balanced model reduction method. Then the optimal placement of actuators are founded by using GA(Genetic Algorithm) based on controllability Gramian matrix. Since the results of active control under white-noise excitation is not good, This paper proposes the specific selection method of weighting function of mixed sensitivity method and the H? controller is designed, and the numerical simulation is carried out. Finally, the two types of configuration of actuators hardware-in-the-loop experiments are carried out under different external excitation.The results show that the finite element model can be obtained more accurate by using the method of GHM model. The number of freedom of original model is reduced significantly by using combined reduction methods. The results of active control of the plate under first-order sinusoidal excitation, mixed periodic signal excitation and gauss white noise excitation is good by using robust H? controller which designed by this paper's method. Hardware-in-loop experiments of optimized structure are carried out under three different excitations. Vibration response amplitude attenuates 40% and 42% respectively when the incentives are first-order sinusoidal and mixed periodic signal excitation. The root mean square value of vibration response reduces 22% when the incentive is gauss white noise excitation. The optimized structure can control more effectively in a wider frequency range, it proves the correctness of the actuator position optimization and control method is effective.