Numerical Analysis On Bearing Behavior Of Modern Bamboo Structure Column Base With Exposed Steel Jacketing

Modern bamboo structure is a new type of environmentally friendly structure which is used bamboo plywood as the main building materials and based on modern engineering mechanics,experimental science,engineering seismic theory and so on. Column base is an important node which connects the upper pillar and infrastructure or pile cap,it bears the upper load and transfers axial force,bending moment and shear force to infrastructure or pile cap.Column base is not only the major factor in determining the stability and bearing capacity of the underlying steel column but also is directly linked with the whole structure’s internal force distribution and deformation properties. Reinforced concrete material used in the traditional column consumes too much energy and causes serious pollution,So modern bamboo structure which is a new environmental protection material used in the traditional column form is an innovative point of this article. The main research contents are as follows:First,the types,characteristics, research status and design criterion of column base were analyzed and introduced in the paper.Second,the finite element software,ANSYS,was used as the main tool in the numerical analysis of the bearing capacity of column base.Element types and approach of column base model were describled,and the verification on the effectiveness of finite element analysis was given.Then Column base model was built by the finite element software.column s material is modern bamboo in this model,steel sleeve was used on the outside of the model,stiffening rib was used around steel sleeve,baseplate was fixed to concrete foundation by using four bolts in four directions of baseplate.And a comparative analysis of earlier stage, middle stage and late stage of loading was made separately by the way of progressive loading. Analysis shows that column base model mostly contains compression members.Extrusion emerges at the botom of steel sleeve which is the first part of transferring the load,because of the modern bamboo column’s quassation.Existence of stiffening rib enormously improves the stability of the column base model.O verall,interreaction of each memmber is a necessary condition for the proper directions of column base model.At last setting up 11 groups of models of the column base,those different parameters,such as existence of stiffening rib,the changes of casing in height and thickness,the changes of stiffening rib in thickness were considered.The impact of them on column base model was analysed. The analysis results show that:it is necessary to set the stiffener. The stiffener can a large extent improve the stability of the column node. Decreasing the height of the casing will make the stress range of the casing、stiffener and floor larger. At the same time,the maximum stress value decreases greatly. So the height of the casing should not be too small. The change of the Thickness of the casing will make the stress range of the casing、stiffener and floor change. It would not be conducive to the stability of the column,if the thickness of the casing is smaller. So the thickness of the casing should be controlled in the certain range,which should not be too small. It is same to the result of the change of the thickness of the casing,the decreases of the thickness of the stiffening rib would not be conducive to the stability of the column model.On contrary,the stability of the whole model will be stronger. But,in reality,it is not be adocated. So the thickness of the stiffening rib should be proper.