Effect Of Hollow Ratio On The Crashworthiness Of Stainless Steel-Concrete-Steel Double-Skin Tubular Columns

Stainless steel,with excellent anti-corrosion performance and exquisite appearance,is seen as the outstanding modern building material,which has been used for more than seventy years in the structure and it was adopted in many famous buildings,which has not yet found being worn or corrupted.The Empire State Building in New York is built for more than 60 years whose top floors and spire are covered with the stainless steel is still elegant,and its shiny external light texture lasts for a long time.Accelerating the research and application of stainless steel i n the construction field caters to the 13 th Five-Year China Planning of the advocacy of green-construction and material-saving.But it will be at a high cost of full use in the stainless steel structure,and will severely result in restricting its engineering application and promotion.In this paper,the outsourcing plain carbon steel pipe in the stainless steel-concrete-carbon steel double-skin tubular was replaced by stainless steel pipe works of concrete filled steel tube structure,and the stainless ste el tubular hollow interlayer steel concrete composite structure formed can not only perform the corrosion resistance of the stainless steel material but also reduce the construction cost.The stainless steel-concrete-carbon steel double-skin tubular is a component which is filled with concrete between concentric stainless steel and common steel pipe.In this paper,the research work has been focused on the research of static performance.There are a large number of dynamic related cases of collision during the service period of the building components.It was reported that 15% of the damaged bridges in the United States was caused by vehicle collision,and the statistics data in Beijing City showed that more than 50% of Beijing's bridges have suffered from the collision.In a word,the case like collision has been a serious threat to our traffic safety,and it can bring huge economic construction loss,which forces us to accelerate the study of the collision.Therefore,the stainless steel-concrete-carbon steel double-skin tubular is carried out as the object of the study and the research on the Crashworthiness was conducted.The research in this paper is expected to provide the basis and guidance for the crashworthiness design of this type of component.By using DHR9401,18 low velocity impact tests were carried out,and finite element software ABAQUS was used to analyze the whole process of the dynamic response of composite column.The main research content is as follows:(1)Three factors which are hollow ratio of specimen,impact velocity,axial compression ratio were set at the impact test of the stainless steel-concrete-carbon steel double-skin tubular.Three levels were put up of each factor,and a total of 9 groups(18)stainless steel specimens were produced according to the idea of orthogonal test.The data in the test mainly recorded the failure mode of the specimen,the relation curve between the impact force and time,and the curve between the midspan deflection and the time.The experimental analysis showed that the good ductility and crashworthiness performance of the stainless steel-concrete-carbon steel double-skin tubular;the hollow rate is the most prominent factors in three factors through the analysis of orthogonal test,and compared with the other two factors,it has the greatest impact on the crashworthiness of the structure.(2)By using ABAQUS software,the dynamic response process of the collision of the stainless steel-concrete-carbon steel double-skin tubular was simulated,and the finite element model was utilized to consider the parameters of the effect of strain rate,contact friction and boundary condition.It showed the good consistence between the calculation results of finite element analysis and experimental results.(3)The whole process analysis of the dynamic response of stainless steel-concrete-carbon steel double-skin tubular under impact is presented,and its the impact resistance ability was discussed.Structural stability coefficient of the new crashworthiness performance pa rameter was put forward by referring to former parameters named impact platform value.Based on the two sets of parameters,the influence of the void ratio on the crashworthiness of this type of component is discussed,and the reference range of the hollow ratio is given,which provided the design basis for the practical application of this new component.