| Vibration control technology is very important for aircraft and other equipment.Constrained by the added mass ratio,low-frequency,broadband and efficient passive vibration suppression technology is often difficult to achieve.Nonlinear elastic metamaterials refer to sub-wavelength elastic metamaterials or structures with nonlinear dynamic effects.The research shows that strong nonlinear elastic metamaterials can realize low-frequency and broadband vibration suppression under small added mass ratio,which opens up a new idea for vibration control of equipment(especially aircraft),but the research on vibration suppression characteristics of nonlinear elastic metamaterials needs to be further improved,There are many new phenomena,new mechanisms and new design methods worth to explore and research.In this paper,the design method to improve the suppression efficiency of nonlinear elastic metamaterials is explored and applied to the vibration control of aircraft wings.The main research contents are as follows:1.Combined design of linear and nonlinear elastic metamaterials.Based on the one-dimensional elastic model,the design method of combining linear and nonlinear elastic metamaterials is studied.By systematically studying elastic wave propagation and vibration suppression characteristics of different combined design schemes,conclusion is found that the appropriate design combination can make the elastic metamaterials achieve lower frequency,wider bandwidth,more efficient and more robust vibration suppression effect under the same mass ratio.2.The design method of strongly nonlinear elastic metamaterials with metadamping.It is found that based on the collision enhanced energy dissipation mechanism,the metadamping effect can be achieved by designing damping layers at different positions of metamaterials,and the “sandwich” metadamping element can achieve low-frequency,broadband,efficient and robust vibration suppression effect.Then,a nonlinear elastic metamaterial beam is designed and the vibration suppression effect of the metadamping structure is preliminarily verified.3.The application verification about vibration suppression of typical large-scale aircraft wing based on strongly nonlinear elastic metamaterials.Based on the strong nonlinear elastic metamaterial design method,a typical large-scale wing model containing metamaterials is designed and prepared to completed the vibration test.Experiments show that strongly nonlinear elastic metamaterials can achieve low frequency,wide band and efficient vibration suppression with minimal added mass.In short,this paper studies the wave propagation and vibration suppression characteristics of nonlinear elastic metamaterials based on theory and experiment and put forward the combination design and metadamping design method of strong nonlinear elastic metamaterials,also completes the application verification of vibration suppression of typical large-scale aircraft wings to realizes excellent lightweight,low-frequency,broadband,efficient and robust vibration reduction effects.This paper promotes the development of nonlinear elastic metamaterials,which is expected to provide feasible theoretical and technical support for equipment and aircraft vibration suppression.So this paper has important theoretical and engineering application value. |
