Integration of Shell FEA with Geometric Modeling on NURBS Surface Representation for Practical Applications

The framework for the linkage between geometric modeling and an analysis based on the NURBS technology is developed in this study. In the present study, The NURBS surfaces were generated by interpolating a given set of data points or by extracting the necessary information to construct the NURBS surface from the IGES format file which was generated by the commercial CAD systems. Numerical examples showed the rate of displacement convergence for the various parameter-izations of the NURBS surface. Quadric surface, which is generated exactly by NURBS representation, was considered. One of the important advantages of the NURBS equation is its ability for exact mathematical expression of quadric shape curves or surfaces. A trimmed surface, which is often encountered during a modeling process in the CAD systems is also presented in this study. The performance of the shell element that is based on Naghdi shell theory integrated with exact geometric representations by the NURBS equation were compared to that of a previously reported FE shell elements in the selected benchmark problems.