Numerical Analysis On Hysteretic Behavior Of Square Steel Tubular Columns Filled With Lightweight Aggregate Concrete

Sustainable development has become the theme of the world’s economic and social development.Green environmental protection,energy saving and emission reduction have put forward new requirements for civil engineering.The component which is made of lightweight aggregate concrete instead of sand aggregate can reduce the self weight by 20% to 40% under the same conditions.The aggregate of lightweight aggregate concrete is often used as th e main material,such as industrial waste,coal gangue and coal ash of thermal power station,while saving materials and reducing environmental pollution.With the pace of the times,it is urgent to explore the related topics of green steel tube lightweight aggregate concrete.In our country,the research of axial mechanics has begun for many years,but there are few literatures on the hysteresis performance of the steel tube lightweight aggregate concrete column.Based on this,the hysteretic behavior analysis model of 14 square steel tube lightweight aggregate concrete columns is established by using the ABAQUS finite element software,on the basis of determining the constitutive relation of lightweight aggregate concrete.The effects of axial compression ratio,length ratio,steel ratio,steel yield,steel yield strength and compressive strength of lightweight aggregate concrete on the hysteresis performance of components are studied.The following conclusions are obtained by data processing and analysis.(1)local buckling occurred in 14 models.The core concrete retards the local buckling of the steel pipe,and at the same time,because of the constraint of the steel pipe,the bearing capacity of the core concrete is improved.(2)the hysteresis loops of the models are more plump,with no obvious pinch shrinkage phenomenon,showing good energy dissipation capability.(3)to increase the length and fineness of the component and the axial compression ratio,the horizontal bearing capacity and the stiffness of the strengthening stage have a tendency to decrease.However,with the increase of the length and slenderness ratio,the stiffness of the elastic phase of the component is significantly reduced,and with the increase of the axial compression ratio,the stiffness of the elastic phase of the component has no effect,and the ratio of the length to the length and the axial compression ratio is different.With the increase of the ratio of the steel and the ratio of the steel,the horizontal bearing capacity of the component is carried out.The stiffness of the force and elastic stage is increased,and the effect of the lightweight aggregate concrete on the horizontal bearing capacity and the ductility of the component is less.The yield strength of the steel has a significant influence on the horizontal bearing capacity of the component,and the horizontal bearing capacity increases with the increase of the strength grade.(4)the influence of various parameters on ductility of components: with the increase of axial compression ratio and slenderness ratio,the ductility of components gradually decreases.With the increase of steel content,the ductility of members increases.The yield strength of steel and the strength of lightweight aggregate concrete have no influence on ductility of members.