The Research Of Stability And Utmost Load Of Truss With Long Cantilever Based On Finite Element

Truss consists of some slim poles with two ends hinged, forming a structure with geometryshape invariable. In extreme loading state, steel truss can exist the following six incidences.1) he whole structure or one part of that falls out of balance as a rigid body.2) The component or link of a structure destroys because of excess of material intension.3) The structure changes into a alterable system.4) The structure or component loses its stability.5) The structure presents itself with excess plasticity deformation.6) The component appears fatigue destroy under the action of repeat force.During the extreme state, stability,the ability of anti-brittleness and anti-fatigue plays themost important role to the structure. This article only deals with the stability and extreme load. Asis known to all, the stability of a structure differentiates with the resolution of stress. Firstly, theinfluence of deformation to stress should be concerned;secondly, it has no sense of differentiatingthe determinate or indeterminate structure. At last, the overlay principle never suits in these cases.In this article, the following researches has been done through the dealing of strain data fromthe construction of a certain gymnasium.1. his article has derived the common matrix of geometry nonlinear structure based onfinite element, it has got the analyzing matrix of geometry nonlinear link element usingRILI-ZI method, and it has been used in solving the extreme load of several examples,then it was contrasted with the result using geometry linear method.2. This article has analyzed the linear flexuosity of truss structure using the classicly linearflexuosity theory, then uses the element analysis program ANSYS to make a geometrynonlinear analysis of practical engineering, at the same time, it was contrasted with thepractical detected results, in order to analyze the stability of the large span truss.Integrating from the above article, the following conclusions can be got. As far as a cantilevertruss is concerned, it is useful to strengthen the node rigidity for improving the utmost load of thestructure, but in the aspect of displacement of the node in the cantilever part, it is on the contrary.In addition in the geometry nonlinear analysis, it is not advisable to neglect the strengthening ofstress to rigidity matrix. During the time of choosing material, it is better to choose material withhigher ratio of flexuosity to the ultimate stress. it can prevent the component from losing stability.