Hybrid CPU/GPU implementation for the FE2 multi-scale method for composite problems

This thesis aims to develop a High-Performance Computing implementation to solve large composite materials problems through the use of the FE2 multi-scale method. Previous works have not been able to scale the FE2 strategy to real size problems with mesh resolutions of more than 10K elements at the macro-scale and 100^3 elements at the micro-scale. The latter is due to the computational requirements needed to carry out these calculations. This works identifies the most computationally intensive parts of the FE2 algorithm and ports several parts of the micro-scale computations to GPUs. The cases considered assume small deformations and steady-state equilibrium conditions. The work provides a feasible parallel strategy that can be used in real engineering cases to optimize the design of composite material structures. For this, it presents a coupling scheme between the MPI multi-physics code Alya (macro-scale) and the CPU/GPU-accelerated code Micropp (micro-scale). The coupled system is designed to work on multi-GPU architectures and to exploit the GPU overloading. Also, a Multi-Zone coupling methodology combined with weighted partitioning is proposed to reduce the computational cost and to solve the load balance problem. The thesis demonstrates that the method proposed scales notably well for the target problems, especially in hybrid architectures with distributed CPU nodes and communicated with multiple GPUs. Moreover, it clarifies the advantages achieved with the CPU/GPU accelerated version respect to the pure CPU approach.Esta tesis apunta a desarrollar una implementación de alta performance computacional para resolver problemas grandes de materiales compuestos a través del método de Multi-Escala FE2. Trabajos previos no han logrado escalar la técnica FE2 a problemas de dimensiones reales con mayas de resolucion de más de 10 K elementos en la macro-escala y 100^3 elementos en la micro-escala. Esto último se debe a los requerimientos computacionales para llevar a cabo estos cálculos. Este trabajo identifica las partes computacionales más costosas del algoritmo FE2 y porta varias partes del cálculo de micro-escala a GPUs. Los casos considerados asumen condiciones de pequeñas deformaciones y estado estacionario de equilibrio. El trabajo provee una estrategía factible que puede ser usada en problemas reales de ingeniería para optimizar el diseño de estructuras de materiales compuestos. Para esto se presenta un esquema de acople entre el codigo MPI de multi-física Alya (macro-escala) y la versión acelerada CPU/GPU de Micropp (micro-escala). El sistema acoplado está diseñado para trabajar con arquitecturas de multiples GPUs y explotar la sobrecarga de GPUs. También, un método de multiple zonas de acople combinado con particionado pesado es propuesto para reducir el costo computacional y resolver el problema de balanceo de carga. La tesis demuestra que el método propuesto escala notablemente bien para los problemas modelo, especialmente en arquitecturas híbridas con nodos CPU distribuidos y comunicados con multiples GPUs. Más aún, la tesis clarifica las ventajas logradas con la versión acelerada CPU/GPU respecto a usar unicamente CPUs

Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015

This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politècnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: ● Formulations and Numerical Methods ● Efficient Methods and Real-Time Applications ● Flexible Multibody Dynamics ● Contact Dynamics and Constraints ● Multiphysics and Coupled Problems ● Control and Optimization ● Software Development and Computer Technology ● Aerospace and Maritime Applications ● Biomechanics ● Railroad Vehicle Dynamics ● Road Vehicle Dynamics ● Robotics ● Benchmark ProblemsPostprint (published version