Topology optimization is used to design multifunctional sandwich panels that fulfill multiple functional constraints. The purpose is to expand the methodology for multifunctional design in earlystages of the vehicle design process, to allow for design of multifunctional vehicle systems thatcan replace multiple subsystems and reduce the total mass of the vehicle. The focus of the research is the inclusion of dynamic behaviour into the topology optimization framework. The casestudy for this research is a train cabin sandwich structure, with the functional requirements beingthe structural and acoustic properties of the structure. The core of the sandwich panel is the designdomain of the optimization . The problem is modelled and solved as a mass minimization topology optimization problem with the structural requirements being translated into constraints onthe static response of the structure and the acoustic requirements being translated into constraintson the response when subjected to time-harmonic loads. The topology optimization problem issolved using the Topology Optimization of Binary Structures (TOBS) method.