Addition of rigid elements to NASTRAN

Four rigid elements, namely, a rigid rod element (CRIGDR) and three rigid body elements (CRIGD1, GRIGD2 and CRIGD3), have recently been added to NASTRAN and will be available in the next public release of the program. The theoretical formulation, the bulk data information and the programming details pertaining and realistic problems are illustrated by employing them in the solution of two helicopter structural analysis problems.