Published online by Cambridge University Press: 04 July 2016
The natural frequencies of a plate or a shell can be changed by altering its stiffness. This can be achieved by appropriately varying the mass or curvature, by introducing initial stresses or by attaching stiffeners to the system. The last method has obvious advantages over the other methods. The natural frequencies are thus raised, lowered or remain unchanged depending on (i) the dimensions of the stiffener relative to the plate or shell dimensions, and (ii) its position.
Department of Mathematics, University of Roorkee, Roorkee, India.
Structural and Aerospace Dynamics Group, Cranfield Institute of Technology, Cranfield