GeoDualSPHysics: a high-performance SPH solver for large deformation modelling of geomaterials with two-way coupling to multi-body systems

This paper presents GeoDualSPHysics, an open-source, graphics processing unit (GPU)-accelerated smoothed particle hydrodynamics (SPH) solver designed for simulating large-deformation geomaterial and their interactions with multi-body systems. Built upon the popular open-source SPH solver DualSPHysics, the solver leverages its highly parallelised SPH scheme empowered by the CUDA parallelisation while extending its capabilities to large-deformation geomechanics problems with particles up to the order of 10⁸ on a single GPU. The SPH geomechanics model is enhanced by a noise-free stress treatment technique that stabilizes and accurately resolves stress fields, as well as an extended modified Dynamic Boundary Condition (mDBC) ensuring first-order consistency in solid boundary modelling. Additionally, the coupling interface between DualSPHysics and the multi-body dynamics solver Project Chrono is adapted for simulating interactions between geomaterials and multiple interacting rigid bodies. Benchmark validations confirm the solver's accuracy in resolving geotechnical failures, impact forces on solid boundaries, and geomaterial-multibody system interactions. GPU profiling of the newly implemented CUDA kernels demonstrates their performance metrics are similar to those of the original DualSPHysics solver. Performance evaluations demonstrate its saving in memory usage of 30-50% and improvements in computational efficiency over existing SPH geomechanics solvers, achieving practical simulation speeds for systems with tens of millions of particles and showing a speedup of up to 180x compared to the optimised multi-core CPU implementation. These advances position GeoDualSPHysics as a versatile, efficient tool for high-fidelity simulations of complex geotechnical systems. Program summary: Program title: GeoDualSPHysics CPC Library link to program files: https://doi.org/10.17632/z4sh62y97g.1 Licensing provisions: GNU Lesser General Public License Programming language: C++ and CUDA Nature of problem: Simulating large deformations in geomaterials and their interactions with movable or fixed solid bodies is critical for addressing engineering challenges such as landslides, soil-machine interactions, and off-road vehicle mobility. While the Smoothed Particle Hydrodynamics (SPH) method is well-suited for modelling continuum-based geomaterial behaviour in these scenarios, critical computational barriers persist, including: (1) numerical instabilities and unphysical noise in large-deformation regimes, (2) inefficiency in scaling simulations to millions of particles for real-world systems, and (3) inadequate frameworks for robust, two-way coupling between deformable geomaterials and multi-body systems. Overcoming these limitations demands stabilized SPH formulations, high-performance computing architectures, and two-way coupling with multibody dynamics solvers. Solution method: The GeoDualSPHysics solver addresses the above challenges by combining (1) a stabilised SPH formulation for geomaterials, featuring a noise-free stress treatment to eliminate spurious oscillations in large deformations and an extended modified Dynamic Boundary Condition (mDBC) for first-order consistent solid boundary modelling; (2) high-performance CUDA-based GPU parallelization inherited from DualSPHysics, enabling efficient simulations of tens of millions of particles; and (3) two-way coupling with Project Chrono via the DSPHChronoLib library, which integrates collision detection, frictional contact models, and joint constraints to resolve interactions between deformable geomaterials and multi-body systems.