Particle dampers are passive vibration control devices that dissipate mechanical energy through inelastic collisions and friction between particles and the housing structure [1]. Because of their complex and nonlinear behaviour, which is governed by particle-particle and particle-structure interactions, numerical simulations are a valuable tool to study these dampers. The Discrete Element Method (DEM) is well suited for such modelling [2]; however, DEM alone cannot represent the structural displacement and frequency response of the support structure. In this context, this work presents an implementation of a coupled DEM-FEM simulation that computes the time-dependent contact forces generated by the particles, which are then applied as loads to the FEM solver in order to obtain the structural response with detailed insights into stress distributions and dynamic response. This approach captures the two-way coupling where the structural displacement influences the particle motion and vice-versa, improving the overall simulation quality and predictive accuracy [3]. Furthermore, the presented simulation uses an in-house developed solver, written in C++ and CUDA, with a heterogeneous computing strategy: DEM calculations are handled by the GPU, while the CPU runs the FEM solver, enabling simulations with over a million particles.