Axial Compressive Performance Of Thin-walled Steel Tube/Bamboo-plywood Composite Hollow Long Column With Binding Bars

The traditional building materials typically represented by steel,cement and brick are the products of high energy consumption,high pollution and high emission,which bring huge environmental pressure and don't meet the requirements of sustainable development.Using environmentally friendly,biodegradable green materials applied to the engineering structures is a useful supplement for traditional building materials and can even gradually replace the traditional building materials within a certain range.It's the only way for construction industry to seek new development.In response to the call of green building materials in the new era,based on our group's previous researches,the axial compressive performance of thin-walled steel tube/bamboo-plywood composite hollow long column with binding bars(SBCCB)was studied in this paper.First,the arrangement of binding bars was changed,4 SBCCB specimens were optimized for the axial compression test.The failure modes were summarized,and the effects of slenderness ratio,net sectional size,row number and relative vertical spacing ratio of binding bars on the failure modes,ultimate load and deformation characteristics were analyzed.Then based on ABAQUS software,the experimental simulation FEM was established.The parametric design was extended to investigate the influences of slenderness ratio,net sectional size,row number and relative vertical spacing ratio of binding bars on the bearing capacity.The results indicated that the failure modes of SBCCB can be characterized by crush of bamboo plywood at the end of column,partial glue failure and compression buckling failure.Increasing the net sectional size is the key factor to improve the bearing capacity.As slenderness ratio increase,the stiffness of SBCCB decreases and SBCCB will earlier enter the elastic-plastic stage,which leads to the larger development of lateral deflection and strain that makes the bearing capacity get lower.The smaller the relative vertical spacing ratio of binding bars is,the more significant the hoop confining effect is when it cooperates with the thin-walled steel tube.Increasing the row number of binding bars is effective for suppressing the glue failure and can lead to different failure modes to enhance the bearing capacity.A calculation method of the bearing capacity is formulated through the nonlinear regression analysis which more fully reflects the change law of bearing capacity,and plot the pillar curves in groups of net sectional size.They can be the basis to design SBCCB whose slenderness ratio is between 40 and 75.