This paper presents a topology optimization method for the frequency response of a
multiphysics system involving fluid–structure interaction. The finite element analysis of the
system is carried out based on the us/pf formulation. The structural domain is governed by
the linear equation of elasticity and expressed in terms of the displacement, us, and the fluid
domain is described by Helmholtz equation via the primary variable of pressure, p f. The
coupling conditions are the equilibrium and kinematic compatibilities at the fluid–structure …