Design Sensitivity Analysis of Dynamic Frequency Responses of Acousto-Elastic Built-Up Structures

Abstract

A continuum design sensitivity analysis (DSA) method for dynamic frequency responses of acousto-elastic built-up structures is developed using the adjoint variable and direct differentiation methods. A variational approach with nonselfadjoint operators for complex variable is used to retain the continuum elasticity formulation throughout derivation of design sensitivity results. Sizing design variables such as thickness and cross-sectional area of structural components are considered for the design sensitivity analysis. A numerical implementation method for continuum DSA results is developed by postprocessing analysis results from established finite element analysis (FEA) codes to obtain the design sensitivity of displacement and pressure performance measures of the acousto-elastic built-up structures. The numerical method is tested using passenger vehicle problems. Accurate design sensitivity results are obtained for analysis results obtained from MSC/NASTRAN and ABAQUS FEA codes.