Engineering workflows are habitually split into a modelling phase and a consecutive analysis phase, which is primarily driven by the finite element method (FEM). However, bridging the gap between design and analysis remains a sophisticated problem and may consume a vast amount of computational as well as manual operations, especially in highly iterative development processes. To avoid this major bottleneck, Isogeometric Analysis (IGA) and later Isogeometric B-Rep Analysis were developed. They rely on the mathematical descriptions of Computer Aided Design (CAD), such as NURBS- and B-Spline-based boundary representation (B-Rep) models. However, classical B-Rep formulations describe a solid only by its boundary faces and do neither provide any physical nor geometrical description of the interior. Therefore, the IGA concept cannot be applied to three-dimensional structures in a straightforward manner. To overcome this issue and to facilitate the modelling with solid-based formulations, a design-through-analysis workflow is presented which avoids demanding boundary-fitted meshes. The focus lies on a fully automated CAD-integrated analysis for 3D solid models in the scope of explicit dynamics and crash simulations. Therefore, efficiency with respect to time step size and cost per time step plays a key role in our approach and distinguishes it from already existing methods. In a first step, the geometry is retrieved from the CAD system as a stereolithography (STL) representation and embedded into the parameter space of a regular grid composed out of trivariate B-Splines. Please note that the utilization of B-Splines as basis functions is crucial for the explicit time step. The STL defines the geometrical borders to construct efficient integration rules for trimmed knot spans and additionally provides an intrinsic parametrization for contact formulations and visualization purposes. After these preprocessing steps, the required model data is passed to a solver for analysis, e.g. to LS-DYNA via a user-defined data interface.
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Engineering workflows are habitually split into a modelling phase and a consecutive analysis phase, which is primarily driven by the finite element method (FEM). However, bridging the gap between design and analysis remains a sophisticated problem and may consume a vast amount of computational as well as manual operations, especially in highly iterative development processes. To avoid this major bottleneck, Isogeometric Analysis (IGA) and later Isogeometric B-Rep Analysis were developed. They re...
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