Reduction method of active transmitted power of a specific wave mode in undamped waveguides

Abstract

This paper addresses a method for devising an undamped periodic structure that suppresses energy propagation due to a specific wave mode based on the Wave and Finite Element (WFE) method. Then, structural modifications to reduce the active transmitted power are derived by solving an inverse eigenvalue problem of the WFE method. In solving the inverse problem, it is important that the solution is feasible in the sense that it is low-cost and easy to fabricate as an actual mechanical structure. Therefore, in the proposed method, the designer specifies the regions in which structural modifications may be made before solving the inverse problem. As a result, the solution of the inverse problem is approximated within these regions. Finally, the method allows us to suggest feasible structural modifications necessary to reduce the amount of active transmitted power for a given wave mode and a given frequency. However, this method cannot consider the changes in wave numbers due to structural modification. It should therefore be noted that this method cannot be used to achieve significant reductions in active transmitted power due to large-scale structural modification.

Keywords

• wave analysis
• transmitted power
• structural modification
• wave and finite element method
• metamaterial