Abstract: A structure model representing a physical object, a fluid model representing a fluid domain, and a set of particles representing a fluid-structure interaction (FSI) interface between the fluid model and the structure model are received in a computer system. Fluid behaviors of the fluid domain are simulated using the fluid model. Respective friction and pressure forces are calculated at the set of particles of the FSI interface. Each particle's friction and pressure forces are calculated from the simulated fluid behaviors and each particle's location in the fluid model. Structural behaviors of the physical object are simulated using the structure model in response to the friction and pressure forces at the set of particles on the FSI interface. The simulated structural behaviors update each particle's location. The updated location is used in the subsequent calculations of the friction and pressure forces.