Study on the seismic performance of corroded H-shaped steel columns

Abstract

Low cycle cyclic loading tests of 7 corroded H steel columns (seismically compact section, highly ductile member) were performed, so as to investigate the effect of corrosion on the seismic behavior of H-shaped steel columns. Based on the monotonic tensile test, the relationship between mechanical properties and surface morphology of corroded steel were studied. The failure mode, lateral capacity, ductility and energy dissipation of H-shaped steel columns were studied by the low cycle cyclic loading tests. Furthermore, the effects of local corrosion and axial compression ratio on the seismic behavior of corroded H-shaped steel specimens were also investigated in the finite element analysis. The results showed that with the corrosion degree increasing, the deformation area of flange and web of corroded specimens decreased with a maximum decrease of 22%. The height of the buckling center decreased and that of some specimens decreased by 30%. The ultimate lateral capacity and stiffness of specimen H6 with the most severely corrosion degree decreased at a ratio of 27.4% and 26.3% respectively. Eventually, the degradation model of hysteretic energy dissipation and ductility coefficient of corroded H-shaped steel columns were established. In addition, the analytical results showed the hysteretic behavior of compression-bending members with flange corrosion and large axial compression ratio decreased rapidly. When the mass loss ratio reached 22% with axial compression ratio of 0.6, the peak load and hysteretic energy decreased at a ratio of 35% and 70% respectively. Consequently, the components with flange corrosion and large axial compression ratio should be paid enough attention to.