Effect of Beam Rigidity on the Lateral Stiffness of a One-Storey Frame

The present work deals with the effect of beam to column rigidity ratio on the lateral stiffness of a frame. This investigation is relative to the case of a one-storey one-bay frame. The displacement method is used to formulate the global stiffness matrix of the frame. The treated problem consists of applying a lateral force at the storey to obtain its displacement and deduce the lateral stiffness. It is found that the lateral stiffness of the frame is greatly influenced by the beam to column rigidity ratio. A high value of the latter makes the overall stiffness corresponding to the sum of each column’s stiffness. For intermediate values, the influence of the beam becomes important and must be considered in the structural analysis. For very lower values, the columns behave as hinged at their top. The provided plotted curves allow finding the lateral stiffness for different base boundary conditions of the columns.