Concise Equations and Program for Exact Eigensolutions of Plane Frames Including Member Shear

Summary

A unified notation is adopted to present concise member equations for a Timoshenko beam-column and a static beam-column with finite shear stiffness. The Fortran coding necessary to incorporate these equations into a previously published computer program is given. The resulting program enables any number of exact natural frequencies or elastic critical buckling loads of rigidly jointed plane frames to be calculated using an algorithm which ensures that none can be missed. The corresponding mode shapes can then be retrieved by a simple technique which offers improved accuracy over more established methods. The program contains approximately 250 Fortran statements and has been designed to minimise core store requirements at the expense of computation time. The use of the program as a ‘black box’ is fully explained with illustrative examples.