On the use of model truncation to extend the applicability of the finite element method to higher frequencies

Abstract

Many structural acoustics problems of interest can be modeled as a vibrating elastic structure situated in and fully coupled to an infinite acoustic fluid domain. To model such problems using the finite element method, techniques have been developed to approximately enforce the Sommerfeld radiation condition at the boundary of the computational domain and prevent spurious boundary reflections from adversely affecting the calculated solution. These techniques include radiation boundary conditions, infinite elements, and perfectly matched layers. It is well known that due to computational constraints, the finite element method is often restricted to relatively low frequencies. However, many of the same techniques that have been used to enforce the Sommerfeld radiation condition can also be used to truncate the computational domain further and allow the finite element method to be used to study higher frequency problems where the structural acoustic response is relatively localized. This talk explores this model truncation application.Many structural acoustics problems of interest can be modeled as a vibrating elastic structure situated in and fully coupled to an infinite acoustic fluid domain. To model such problems using the finite element method, techniques have been developed to approximately enforce the Sommerfeld radiation condition at the boundary of the computational domain and prevent spurious boundary reflections from adversely affecting the calculated solution. These techniques include radiation boundary conditions, infinite elements, and perfectly matched layers. It is well known that due to computational constraints, the finite element method is often restricted to relatively low frequencies. However, many of the same techniques that have been used to enforce the Sommerfeld radiation condition can also be used to truncate the computational domain further and allow the finite element method to be used to study higher frequency problems where the structural acoustic response is relatively localized. This talk explores this m...