GIRAFFE: Generic Interface Readily Accessible for Finite Elements

This work proposes a simulation software in the context of solid mechanics, for engineering analysis. The objective is to represent complex multibody systems composed of rigid or flexible parts to predict their static and dynamic behavior. The Generic Interface Readily Accessible for Finite Elements (GIRAFFE) is a novel platform for implementing and simulating multibody rigid/flexible dynamics. It provides an environment to couple strategies to handle multibody mechanical problems, such as the finite element method (FEM), multibody dynamics (MBD), or the discrete element method (DEM), looking at the common mathematical structure of all such methods. Therefore, it is a platform that combines features of distinct methods, writing them in a compatible manner, convenient to implement and simulate complex systems composed of multiple bodies. The software is under continuous development employing a code structure to provide easy expansion and possible treatment of distinct methods among FEM, DEM and MBD. The already implemented resources include rigid bodies, geometrically-exact beams/shells flexible bodies, employing FEM approximations, such as flexible solid particles modeled by the Virtual Element Method (VEM). Equality constraints can be used to restrict body motion, such as inequality constraints in the context of mechanical contact enforcement. This includes an automatic contact detection engine. GIRAFFE code is open-source and has been used to simulate offshore risers/pipelines, wind turbines, particulate material mechanics, woven textiles, wheel-rail interaction, and many other applications. The overall code structure that provides its versatility in expansions, its background, its guidelines, and examples of applications are detailed in this paper.