Felix Ospald

Programming support for the flexible coupling of distributed software components for scientific simulations

In this article, we investigate the flexible coupling of distributed software components that are required for an optimization process of lightweight structures built from hybrid materials. The software components include computationally intensive applications for the simulation of hybrid structures, control applications for implementing the optimization process as well as data-oriented applications for the generation, management, and visualization of simulation data. The participating software components and application programs are described to demonstrate their strongly varying functionalities as well as the diversity of data exchange methods that need to be considered for the data coupling. Furthermore, we present the design and usage of a software library with transparent data coupling mechanisms for software components that are flexibly distributed among different computing resources.

NONLINEAR COMPOSITE VOXELS AND FFT-BASED HOMOGENIZATION

The FFT-based homogenization method of Moulinec-Suquet [14] has reached a degree of sophistication and maturity, where it can be applied to microstructures of industrial size and realistic scope. However, for non-linear or load-path-dependent problems the method reaches its limits, in particular if variations of the geometry are considered or the determination of the full material law on the macro-scale is required. Time and memory considerations are primarily responsible for these limitations. This work focuses on the composite voxel technique, where sub-voxels are merged into bigger voxels to which an effective material law based on laminates is assigned. Due to the down-sampled grid, both the memory requirements and the computational effort are severely reduced, while retaining the original accuracy. We discuss the extensions of linear elastic ideas [6, 9] to incremental problems at small strains. In contrast to conventional model order reduction methods, our approach does neither rely upon a “offline phase” nor on preselected “modes”. We demonstrate our ideas with several numerical experiments, comparing to full-resolution computations heavily relying upon our MPI-parallel implementation FeelMath [1].

SIMP Based Topology Optimization for Injection Molding of SFRPs

Today there exists a huge demand for technologies which enable and facilitate the mass production of fiber reinforced composites. Injection molding of Short Fiber Reinforced Plastics (SFRP) is a quite popular method especially in the automotive industry, providing high stiffness levels on the one hand and complex moldable shapes on the other hand. Due to the high cost of mold production and injection molding machines, nowadays lots of research is done to improve models and to develop software for the simulation of this process. This allows to detect problems with the mold design and optimization of the part performance and quality at an early stage of the development.