Research On Static Response Of Structure System With Uncertainties Based On Interval Method

When engineering problems are abstracted to theoretical models, someuncertain factors maybe appear. Uncertainties widely exist in the process ofstructural analysis and design for engineering, which can not be ignored simply. Atpresent, there are three main methods for uncertain modeling, such as probabilitymethod, fuzzy method and interval method. Moreover interval analysis method is aneffective method for the analysis of uncertain factors which real probability statisticdatum is not obtained.This method is discussed in detail in this paper. The intervalanalysis method for uncertain structure system with nonlinear material on whichthere is no much research yet is studied and discussed deeply. Becauseoverestimation is one main limitation in interval computation, computation ofinterval function and solution of interval equations set are transformed into generaloptimization problems to determine the boundary of each interval element in thesolution in this work. Genetic arithmetic of real number coding is used to solvegeneral optimization problems. Corresponding calculation software is edited.Three different situations for typical nonlinear beam and truss system are studiedand discussed sufficiently. The three situations are: (1) structural parameters arecertain, the critical value of load which cause structural parts appear nonlinear ofmaterial and the static response of structure system under the corresponding criticalload are discussed. (2)structural parameters are uncertain, the bound of critical valueof load which cause structural parts appear nonlinear of material isdiscussed.(3)structural parameters and load are uncertain, the bound of static responseof structure system is discussed.