ABSTRACT
3 monotonic tests and 9 cyclic tests according to ECCS loading procedure were carried out in Cluj Laboratory. The tested composite columns of fully encased type were subject to a variable transverse load at one end while keeping a constant value of the axial compression force into them. An analytical interpretation is given briefly for the monotonic tests which constitute references for the cyclic ones. In spite of the complex evolution of the hysteretic cyclic curves representing the transverse force versus the associated displacement up to a pronounced deterioration of the column bases, a simplified characterization is proposed for the loss of resistance, the reduction of stiffness and the capability to dissipate energy. The last part of the paper is devoted to an attempt to determine approximate values of the behaviour factor q of one-storey frames with dissipative zones in composite columns similar to the tested ones.
