Modeling of joints deterioration in dynamic analysis of reinforced concrete frames

The paper presents one possibility for including a joints rotational deterioration in nonlinear dynamic analysis of reinforced concrete frame structures, applying beam finite elements (BFE). Unlike the standard BFE approach, which puts emphasis on the material properties change as a principal (or even the only) reason of a nonlinear system behaviour, the proposed procedure suggests computation of beam stiffness matrix based on both material properties and joint rotational stiffness change. The quality of the approximation, obtained by application of this procedure, will be illustrated by a numerical example.