Rocking steel shear walls with energy dissipation devices

Conventional steel panel shear walls (SPSWs) comprise thin steel plates framed by beams and columns. These walls have been developed as ductile systems which resist seismic forces through a combination of shear resistance from the plates and flexural resistance from the frames. The internal shear forces in the plates are resolved into diagonal tension and compression principal stresses and after the compression diagonal buckles, the plates behave effectively as tension cross bracing. The ductile action is achieved through tensile yielding of the web plate and a plastic hinge is formed at the beam ends, with the columns expected to remain elastic. Although this system, under severe earthquakes, dissipates considerable energy through the yielding of selected members, structural damage with residual deformation may make repair difficult. Therefore, an innovative steel panel shear wall is being developed by combining the advantages of the conventional wall system with a centralised rocking mechanism and energy dissipation devices to produce a lateral force resisting system with a low damage design solution that is intended to remain elastic during the rocking and expected to return to original position after an ultimate limit state level earthquakes. During severe earthquakes, the columns move above or below the original position and the energy dissipation devices provide restoring forces to pull back the columns. A rocking base point at the bottom middle of the wall maintains the stability of the structure. This paper presents the concept and numerical analysis of this wall focusing on the energy dissipation device system.