Research On Adaptive Vibration Control Of Smart Constrained Damping Thin Plate Structure

Lightweight is an inevitable trend in the development of automobile bodies,but light weight will lead to more prominent low-frequency vibration and noise problems in cars.The Smart Constrained Layer Damping?SCLD?vibration active control technology combines the advantages of passive constrained damping technology with active control technology.and it is possible to obtain better control effects in a low frequency range and a wide frequency range,and in particular,it has an ideal suppression effect on vibration in a low frequency range.In this paper,the edge-constrained thin steel plate with partial coverage of SCLD laminated structure is taken as the research object,and the active vibration control is studied.Firstly,the GHM damping model is used to describe the constitutive relationship of viscoelastic materials.The piezoelectric equation is used to represent the electromechanical coupling characteristics of piezoelectric materials.The system dynamics model of SCLD structure is established by combining finite element modeling method and contrast modal experiments show that the established kinetic model can accurately express the dynamic characteristics of SCLD structures.Secondly,the position of the piezoelectric actuator is optimized by the modal strain energy criterion.Under the premise of the actuator position determination,The sensor position optimization objective function considering the influence of the residual modality is constructed by using theH₂ norm of the system,and the ergodic method is used to determine the position of the sensor.Thirdly,aiming at the large degree of freedom of the model,the model is reduced by the dynamic reduction in the physical space,the state space complex mode truncation and the internal balance reduction method.Examples and modal tests show,the joint reduction method can greatly reduce the degree of freedom of the original model,and can obtain an accurate model with low dimension and considerable controllable in the low-order range.Fourthly,aiming at the uncertainty of the system model,The self-extracting reference signal based on transfer function is used as the adaptive filtering control algorithm of feedforward input,and the effectiveness of the control algorithm is verified by simulation analysis.Finally,a hardware-in-the-loop experimental platform was built to study the active vibration control of the edge-constrained thin plate with partial coverage of the SCLD under three different external excitations.The experimental results shows that the vibration response amplitude is attenuated by about 70%under the excitation of the first-order natural frequency single-frequency sinusoidal signal;Under the excitation of the mixed periodic signal of the first three natural frequencies,the vibration response amplitude is attenuated by about 37%;The rms value of the vibration response amplitude is reduced by 14%under the excitation of the finite bandwidth Gaussian white noise signal in the frequency range of 20-100 Hz,the control algorithm achieves the ideal control effect.