Isogeometric Analysis (IGA) has been established as an exceptional tool bridging the fields of Computer-Aided Design (CAD) and Computer-Aided Engineering (CAE) by using the same NURBS (Non-Uniform Rational B-Splines) as basis functions in finite element analysis. Accordingly, the main goal of IGA is to make the simulation as close as possible to the exact CAD description, ensuring higher accuracy and model conversion is not needed. Furthermore, Isogeometric B-Rep Analysis (IBRA) was developed, taking into account the geometry description in CAD, which is the key to the realization of IGA. Therefore, IBRA is an extension of the IGA idea to the CAD-based B-Rep models and opens the possibility of dealing with complex trimmed NURBS patches.
The following list contains the basic requirements concerning the formulation of the IBRA method:
IBRA provides a design-through-analysis workflow for creating a direct computation on CAD models. This workflow seamlessly links the CAD generator, which develops and modifies the input CAD model, the solver for IBRA, and the interface pre- and processing tool, allowing direct analysis within the program. The Rhino plugin Cocodrilo is one example of an open-source CAD-based pre- and post-processing tool. It pairs with the open-source finite element analysis software Kratos Multiphysics, which supports the IBRA developments.
Due to all of the developments related to the CAD basis of the IBRA structure, it is possible to make the CAD model the center of the simulation, where any results remain in the description of the exact CAD model. It enables the development of mapping methods to transfer the result from different surface discretization to the B-Rep CAD model and vice versa. A multidisciplinary workflow with various discretization and solvers can then be associated with the exact geometry. The extension of the IBRA structure simulation via corresponding mapping operators for coupling to fluid simulation, for example, enables the Fluid-Structure Interaction (FSI) simulations with the CAD master model. Likewise, the principle of the CAD master model can be expanded for different physics such as thermal, soil, coupling with the standard structural mechanics mesh, and more.