EXPERIMENTAL STUDY ON MECHANICAL PROPERTIES OF CONCRETE-FILLED OPENING HOLE DAMAGED STEEL TUBULAR MEMBERS

In order to study the mechanical properties of concrete-filled opening hole damaged steel tubular members,14 concrete-filled opening hole damaged steel tubular specimens were designed for the axial compressive test.The change parameters of opening damage rate,concrete grade strength,slenderness ratio were considered.Through this test,the whole mechanical process and failure pattern of all specimens were observed,the failure mechanism,load-deformation and stress-strain curves of concrete-filled opening hole damaged steel tubular specimens were obtained,The influence of change parameters including opening damage rate,concrete grade strength,slenderness ratio on the mechanical properties of concrete-filled opening hole damaged steel tubular members were analyzed.Test results indicated that the specimens in the loading late stage had good ductility;the failure pattern was the local buckling and tear failure.The opening damage rate of the specimens has some degree of impact on the failure pattern and ultimate bearing capacity.Finally the calculation method of bearing capacity of concrete-filled opening hole damaged steel tubular was discussed,based on the formulas of existing criteria,and the result showed that while the opening damage rate was not big( 0.8%),the calculated results by the existing standard methods of concrete-filled steel tubular were safe.