2019 年 85 巻 879 号 p. 19-00171
Since interior noise of an electric vehicle driven by motor has no engine noise, the contribution of the road induced noise at the low-middle vehicle speed range is higher and the noise is more noticeable for passengers compared to a conventional internal combustion engine vehicle. For this background, to reduce the road induced noise, this paper proposes a new method for suppressing the resonance response of the two vibration systems coupled by springs, which simulate a car body assuming the use of semi-active stiffness control. When the compliance matrix at coupling degrees of freedom is decomposed into eigenvalues and eigenvectors, it is known that resonance responses of a whole structure depend on the product of the eigenvector corresponding to zero eigenvalue and the compliance matrices of subsystems. Therefore, we proposed a method to suppress resonance response by setting the product to a zero vector. Firstly, an eigenvector is specified to achieve the zero vector. Then, to realize the specified eigenvector, the coupling stiffness between two subsystems, which is used in semi-active control, is changed. Finally, we apply this method to a beam structure and verify its effectiveness.
