Plastic limit load of plane frames with frictional contact supports

On the basis of the bipotential theory, published in previous contributions, the objective of the work presented in this paper is to establish an extended formulation of limit analysis theory for frames in presence of the unilateral contact with Coulombʹs dry friction at supports. The kinematic and static approaches are formulated by the calculation of the total dissipation power of the frame. As it will be shown, on account of the presence of contact with friction, the two approaches are coupled in the sense that the kinematic limit analysis contains static variables and converse. To deal with, an iterative algorithm, based on successive approximations method, will be described here. The study of a simple example, consisting of a rectangular frame, demonstrates that the coefficient of friction value affects the plastic limit state and therefore the limit load and the collapse mechanism taking place too.