INVESTIGATION OF THE CREEP BUCKLING OF A ROD ON THE BASIS OF THE CALLADINE-DRUCKER THEOREM

The problems of stability and creep buckling of rods were solved in various formulations in [1-3]. Since it is impossible to determine exactly the critical time instant which corresponds to the catastrophic buckling growth, various approximate methods are used in the problems of creep buckling considered below. Among the latters are such methods as the replacement of the real rod cross-section by a perfect H-section [5, 6] or application of the Calladine-Drucker theorem to the approximate expression of the curvature rate of the curved rod axis [7, 8]. In the present paper, the latter approach is developed and the influence of various approximate expressions for the additional energy dissipation in the rod on the calculated value of the critical time is analyzed.