Experimental study on the seismic behaviour of composite shear walls with stiffened steel plates and infilled concrete

A new type of composite shear wall, composed of dual steel plates, vertical stiffening steel plates to connect the dual plates and concrete infilled in the vertical channels formed by these steel plates, is proposed. Fifteen specimens were tested under horizontal cyclic loads, along with a constant vertical axial force, to investigate their seismic behaviour. Specimen failure mainly included three modes: severe local buckling at the corners of the flange plates and boundary channels, damage of the concrete occurring in the middle and bottom of the shear wall and local buckling waves originating at the middle of the specimen. All the specimens exhibited a good deformation capacity: the ultimate drift ratios of the specimens reached an average value of 4.55%, and the ductility has an average value of 4.0. The test results indicated that the thickness of the shear wall and the number of channels in the shear wall have a significant effect on the ductility of the specimens. However, changing the number of channels in the walls has a negligible effect on the shear strength of the wall. Formulas to predict the maximum shear strength and initial stiffness of the shear wall are proposed, and it is verified that they can provide a satisfactory prediction for most specimens, with an error within 10%.