SEISMIC BEHAVIOR OF MASONRY WALLS - MODELING OF HYSTERETIC RULES

A method of modifying the lateral load-lateral displacement relationsh ip obtained by a simple monotonic racking test to represent the skelet on hysteresis curve of an arbitrary dynamic response of a reinforced-m asonry wall is proposed. The results of tests of 32 equal reinforced-m asonry walls, tested by imposing monotonically increasing displacement s, cyclic lateral displacements of two different shapes, and simulated displacement seismic response, have been used as a basis for the deve lopment of the procedure of modification. The amount of input energy, defined as the actuator work done to deform the specimens during the t est, has been taken into account as the decisive parameter for carryin g out this modification. On the basis of experimental results, correla tion factors between the monotonic and cyclic hysteresis envelope curv es, as well as stiffness and strength degradation parameters, which de fine the hysteretic rules, have been evaluated. Good agreement between predicted and experimental cyclic behavior of the walls has been obta ined.