Axial Compression Behavior Of Square Thin-Walled Steel Tube/Bamboo Plywood Composite Hollow Column With Binding Bars

With the rapid development of construction industry in our country,the natural resources consumption and environmental pollution is becoming a serious problem.Therefore,the construction energy conservation and emissions reduction,green and sustainable development has become an urgent demand.Bamboo resources is very rich in China,but the utilization of this resources is low.It is broad prospects for development that if we can combine steel with bamboo,and apply to the building structure.On the basis of existing research,a new type of square thin-walled steel tube/bamboo plywood composite hollow column with binding bars(SBCCB)was proposed and studied on its axial compression behavior.Firstly,9 composite column specimens were designed and manufactured,and the axis compression test of SBCCB was designed.Secondly,9 SBCCBs were used to perform the axial compression tests.The failure modes of SBCCB loaded were investigated,and the influences of the net cross-sectional area,slenderness ratio and sectional combination mode of SBCCB on the crack load and ultimate bearing load of SBCCB were analyzed.The ultimate compressive stress of SBCCB was compared to that of the existing SBCC.The results indicate that the compressive damage of SBCCBs are primarily the broken damage to bamboo plywood material and the glue failure between the matrix interfaces at the end of column and the middle of column between binding bars.The ultimate bearing capacity is not only related to the net cross-sectional area and slenderness ratio,but also related to the sectional combination mode of SBCCB.The binding bars can effectively suppress the glue failure,change the ultimate failure mode and significantly improve the ultimate carrying capacity of SBCCB.Compared with the SBCCs,the ultimate compressive stress of SBCCBs can be averagely increased by 26%.The calculating formula for the axial compression bearing-capacity of SBCCB was derived through the nonlinear regression analysis.The calculation results are in good agreement with the test results.Finally,the software ABAQUS is used to carry out the simulation analysis for 25 SBCCB models(including 9 test specimens),and the results and influencing factors are validated.From the point of the overall result,the analysis results of the ultimate bearing capacity is in good agreement with the experiment results.Therefore,it is feasible to SBCCB specimen with finite element analysis.The method of numerical simulation analysis can better guide and even replace the experimental research.