The inelastic response of framed structures depends on the interaction between forces exisitng at sections where yielding occurs. Force-displacement relations, incorporating the effects of such interactions, are derived for a typical element of the framed structures. The application of these relations to derive the equations of motion of framed structures is analyzed and illustrated for a simple space-frame. The dynamic response of the frame is obtained and it is shown that inelastic interaction between forces during yielding has a significant effect on the response.