THE SECOND ORDER ELASTIC ANALYSIS OF PLANE STEEL STRUCTURES WITH TWO ROTATIONAL SPRINGS

A new calculation model for the second order elastic analysis of plane steel bar element structures is presented by replacing the general bar element with a new one, which has two rotational springs at its ends. By revising its rotation displacement equation, the rigidity matrix of this kind of structure is derived. The elastic and second order elastic analysis programs of this kind of structure are worked out. Two steel frames with semi-rigid connections are calculated with these programs, and part of results of these examples obtained in this way is compared with the results from limit element method. The results of calculations show that this model is reliable and helpful to the structural designs.