Experimental Study And Theoretical Analysis Of Load Bearing Behavior For Key Connection Of Tower Boiler Steel Structure

1000MW tower-type boiler uses full suspension and full bolt connections all-steel braced frames.The main supporting structure can be divided into five major layers,and the components are all with large box-type sections.Because that the size of structural connections of the steel braced frames is large,the load transferred and the installation requirements are high.Therefore,the research is of great importance.In this paper,first,experiments and studies have been performed on the key nodes of the main supporting framework at a reduced scale;afterwards,ABAQUS simulation software is used to analyse the force of the nodes.At last,AISC is applied to calculate the internal force of the bolt group of the nodes.On the basis of experiment results and guided by numerical modeling,and also referring to the design specifications of steel structure in the US,this paper is supposed to be a supplement for the theoretical design method.The traditional theoretical calculation hypothesis is to be adjusted to satisfy the design capacity of key nodes.This paper mainly includes:(1)The test specimen are designed at the reduced scale of 1:6.The key nodes are respectively: the column base plate connection,the beam-column brace connection,and the main girder support brace-column connection.The material characteristic test and anti-sliding test have been performed on the standard specimen of test material of the nodes.In this way,the elasticity modulus,yield strength and poisson ratio,as well as the friction coefficient of the steel material are confirmed.The friction coefficient of the experiment value is ?=0.2.(2)The static load experiment has been performed on the specimen of key nodes.Detailed analysis has been made for the internal force and displacement during the process and the safety of the key nodes have been proved.The ultimate capacity of column base plate connection is 6 times of the design value.The ultimate capacity of beam-column brace connection is 15 times of the design value.(3)ABAQUS simulation software is used to perform finite element simulation on the specimen to analyse the force condition and the reason of sliding at the friction side.Also the components are optimized.By summarizing US steel structure design guide and AISC standard,the design methods and suggestions of the steel structure nodes are provided.