Analysis Of In-plane Stability Of Steel Frame With Bracket

Centrifugal cast steel tube is a new kind of steel tube, which has began being applied inconstructions recently. When centrifugal cast steel tube is used as column of frame with bracket,the column is prismatic. The beam-to-column joint uses perforation diaphragm in frame whichcolumn is centrifugal cast steel tube. These modus operandi differ from the modus operandi inChina. There have been little research on the frame with centrifugal cast steel tube column. Thispaper will do research on the performance of in-plane stability of this kind of frame. Plastic-zone method is used to study the in-plane stability performance of this kind offrame, and load increment method is adopted to analyze the non-linear process of frame bearingloads. On the base of large deformation theory in solid mechanics, three-dimensionalisoparametric solid element is introduced, and equation of balance of non-linear geometrical finiteelement increment is concluded, the method of linearization of non-linear equation and the buildof unitary balance equation is discussed. The elastic-plastic constitutive relation under largedeformation and elastic-plastic increment balance equation and the judgement of elastic-plasticstate and the gradual integral of elastic-plastic constitutive relation is discussed. This article alsodiscusses the solution of big linear equation group and the means of memory of stiff matrix. On the foundation of these above theories, the program that can get the ultimatebearing-load capacity is developed by using three-dimensional isoparametric solid element.Non-linear geometrical effect and elasto-plasticity can be taken into account in the program. The ultimate bearing-load capability of frame and local zone consists of bracket and joint isstudied respectively by making use of program. When the capability of local zone is underresearch, effect of different vertical load eccentricity on the capability is considered, the twodifferent connect ways of perforation diaphragm and hoop is compared and some other factors arealso considered. The influence of different load cases on the capability of frame is taken intoaccount, while the frame is being studied. Through analysis of some examples, some usefulconclusions are got and the rationality of theory and the validity of program is validated.