Study on the Optimization of the Distribution of Absorbing Material on a Noise Barrier

Abstract

Noise barriers have been widely used to decrease the transportation noise. How to utilize limited structure and material to achieve the environmental requirements for noise control is an important research topic. This research combines the use of boundary element method and SIMP to generate an acoustic topology optimization method and applies this optimization method to optimization distribution of absorbing material installed on the noise barrier’s edges. Optimality criteria method is used to update the design variables and look for the final optimal solution. A new material interpolation scheme for acoustic problems based on SIMP is given, where the interpolation variable is not real structural density used in conventional SIMP, but fictitious material density deciding the normalized surface admittance. It is noteworthy that gray elements exist in the acoustic optimization analysis based on SIMP. However, a modified method based on a smoothed Heaviside function is applied to eliminate the gray elements. In order to demonstrate the validity and efficiency of the proposed algorithm in this paper, vertical barrier and T-shaped barrier with two wells are used for the numerical analysis, respectively.