The Mechanical Analysis Of The Joint Of The Reinforced Concrete Column-mansard Steel Beam System

For the structure system of reinforced concrete column-mansard steel beam,due to its geometric characteristics,the comprehensive effect of the structure caused by the break point across the middle,and the constraint state of the joint position,it produces the ability to resist deformation of the straight steel beam,which is different from that of the straight steel beam.This performance also has a certain effect on the horizontal thrust of the internal force at the joints of the structural system.At present,scholars have formed a mature and widely accepted theoretical system for the study of mansard steel beams(as known as herringbone steel beams,two-hinged inclined beam arches)and common reinforced concrete columns.However,there has not been a clear design code or atlas of the reinforced concrete column-mansard steel beam structure system,and there is no theoretical research system in the current steel structure design code and code.In some projects,the designers design this structure with reference to the Technical Code for Steel structures of Light-weight buildings with Portal Steel frames CECS102(2002).However,the code does not involve in the design code of the reinforced concrete column-mansard steel beam structure system,which may lead to uneconomical and reasonable design,not optimal enough,resulting in high cost and waste of resources.In this paper,the stress condition of the structural system of the reinforced concrete column-mansard steel beam is the research object.Firstly,the calculation formula of the horizontal thrust and the horizontal displacement at the node is deduced by the theory of the theoretical structure concept diagram,and the influence factors of the stress of the node are determined.Secondly,combining with the theoretical analysis,according to the experimental conditions available in the laboratory,we can overcome the two difficulties of how to innovate the design of the joint and how to measure the internal force at the node,and change the slope P and span L.The test scheme of the whole structure test is designed.In this structure,the static loading test is carried out in 6 groups of the whole structure system,and the relevant test data is measured and the stress and deformation of the node are analyzed.Finally,the finite element analysis software Abaqus/CAE6.14 is used to set up the three-dimensional model of the structure system to carry on the numerical simulation analysis.Then,compare and analyze the theoretical calculation results,test data and software simulation results of the system comprehensively,and draw the conclusions.Considering the present situation of the reinforced concrete column-mansard steel beam structure system,the mechanical mechanism of the joint of the reinforced concrete column and mansard steel beam structure system is studied by three methods:the theoretical calculation,the experimental research and the numerical simulation,in order to achieve the following objectives:1)the calculation formulas of the horizontal thrust and the horizontal displacement of the reinforced concrete column-mansard steel beam structure top system under two symmetrical concentrated loads at the span of 1/3 are analyzed theoretically.The connection mode of the structural system joints and the effect of small horizontal displacement at nodes,on the horizontal thrust at the top of the column at the node of the beam and the column node are studied,and the relevant conclusions of the horizontal thrust on the top of the reinforced concrete column-mansard steel beam structure system are put forward.2)The theoretical calculation formula was compiled into a program by MATLAB,and the statistical calculation of multiple influence factors was carried out.The height H of reinforced concrete column and the span L,of the mansard steel beam were studied.The influence of the slope P and other factors on the deformation and the force of the beam-column joint of the reinforced concrete column-mansard steel beam structure system and its mechanism.3)On the basis of six groups of static loading tests of integral structure,the correction coefficient is introduced to modify the relevant theoretical calculation formula according to the measured relevant test data.4)Using the finite element analysis software ABAQUS/CAE6.14 to establish the three-dimensional model of the structural system,the stress and displacement deformation of the reinforced concrete column-mansard steel beam structure system are numerically simulated,the horizontal thrust and the horizontal displacement of the column top at the joint of the system is studied.5)By synthesizing the theoretical analysis of the three methods,deducing the calculation formula,the experimental research,the finite element software numerical simulation and the data comparison,the further research on the joint of the reinforced concrete column-mansard steel beam structure system is promoted.This paper provides a theoretical basis for reasonable analysis of the actual stress state of the reinforced concrete column-mansard steel beam system j oint,optimization of structural design and improvement of economic benefit of the reinforced concrete column-mansard steel beam structure system.