ABSTRACT
This chapter introduces new static and dynamic recoverable, not an approximation, condensation methods to condense the unnecessary degrees of freedom (DOFs) at the control mesh points of the plate and shell element modeled using the nonuniform rational B-spline (NURBS) surface. Since the introduction of NURBS in computer-aided design applications directly used in the structural modeling, a significant increase of the number of DOFs hinders some design practitioners that are not familiar with the new NURBS geometry concept. By using the sandwich condensation method, it is possible to reduce the number of DOFs due to the NURBS adopted down to the standard four-node 12-DOF plate and shell element, which has many benefits in real applications. The NURBS element codes can be integrated seamlessly into the conventional plate and shell finite element codes. The procedure with an example of condensation is presented with the relevant and complete MATLAB® codes.
