Optimal Placement of Constrained-Layer Damping for Reduction of Interior Noise

Abstract

In this paper, an efficient constrained-layer damping layout optimization method in structural-acoustic systems is proposed. To simulate vibro-acoustic systems, a hybrid model that uses finite elements for structures and boundary elements for the cavity is developed. With a finite element formulation, the intrinsic nonlinearities of viscoelastic damping materials with respect to frequency and temperature are included using a fractional-derivative model. The resulting complex eigenvalue problem is solved using an iterative scheme. The optimal layout of the constrained viscoelastic layer damping on the structure is identified using a gradient-based numerical search algorithm. The sensitivity formulas are derived analytically for acoustic and structural responses. The optimal damping-layer layouts that minimize the added mass with minimum sound pressure level requirements are obtained for different temperatures.