Experimental Study on Static and Low Cyclic Performance of Q460GJC Thick Plates

Abstract

High performance Chinese domestic structural steel (referred to as GJ steel) has been applied to many major construction projects due to its high performance, high yield strength, and good mechanical properties. In this paper, the variations of the static and low cyclic performances of Q460GJC thick plates at different layers in the transverse and Z-direction (along the plate thickness) are described and discussed. Static performance tests under monotonic tensile loading were conducted on the transverse and Z-direction specimens of 25-, 42-, and 80-mm thick steel plates to obtain the stress-strain curve, yield strength, tensile strength, elongation, and reduction of the cross-sectional area after fracture of each specimen. Low cyclic performance tests under equal-strain increase and equal-strain amplitude loading were also conducted on the transverse and Z-direction specimens of 80-mm thick steel plates to obtain the cyclic hysteresis curve, skeleton curve, cyclic strength, and cyclic hardening degree for each specimen. The main findings from this study are the following: (1) the closer the material is to the outer surface of the Q460GJC thick plates, the higher the yield strength and the better the ductility; (2) the yield strength and the reduction in the area of the transverse specimens are higher than those of the Z-direction specimens at the same layer; (3) Q460GJC thick plates have good seismic performance in both transverse and Z-directions at different plate layers; and (4) the closer the material is to the outer surface, the higher the cyclic strength.