Impact Response Analysis of Structures Including T-shaped Cross Section with a New Acoustic Black Hole Having Residual Thickness Supported by Nonlinear Concentrated Springs

Abstract

This paper describes vibration analysis using finite element method with Model Strain Energy Method for structures having T-shaped cross section supported by nonlinear concentrated springs under impact load. The structure is composed of steel layer having a new Acoustic Black Hole in the T-shaped cross section with residual thickness. A viscoelastic damping layer is covered on the acoustic black hole. Finite element for the nonlinear springs with hysteresis are expressed and are connected to the structure modeled by linear solid finite elements in consideration of complex modulus of elasticity. We calculated modal loss factors and transient responses including internal resonances in the eigen modes including coupled motions between the non-linear springs and the structure. From the dominant eigen modes and the time histories, we clarified effects of the new Acoustic Black Hole with residual thickness and nonlinear springs on the nonlinear damped responses.