THE FREE VIBRATION OF THIN RECTANGULAR PLANFORM SHALLOW SHELLS WITH SLITS

Uniform thickness, unstressed, shallow shells of rectangular planform, with slits parallel to one edge, are considered. Each shell is subdivided into several free rectangular shell elements which are joined together and to the boundaries by means of very stiff, artificial, line springs, thereby enforcing the continuity and boundary conditions. Slits are created by allowing the appropriate springs to have a stiffness of zero