The Research On Buckling And Reliability Evaluation Method Of Imperfect Structure

Initial imperfection is one of the most basic imperfections of real engineering structure. Buckling probabilistic performance study of structure with initial imperfection is the important application of structural reliability theory in the field of modern structural stability theory. Buckling allowance loading design based on reliability of structure with initial imperfection, which can consider the random characteristics of imperfection and its variables, is more appropriate for engineering practice situation. Herein, the research of buckling safety design of imperfect structure based on structural reliability exhibit certain theoretical and application significance.This thesis carried out the research of initial imperfection influence on structural buckling reliability.Based on the study of a number of references, the thesis puts forward a safety buckling load design method based on the maximal variation velocity of loading vs displacement. Traditional stable buckling and unstable buckling all have been unified as general bifurcation buckling. According to beam-column theory and AFOSM, the buckling safety margin equations of structure with initial random eccentricity and deflection have been founded. Combination loading including concentrate loading, uniform distribution loading and end moment loading, have been analyzed here, where buckling safety margin equations also have been founded. The influence of initial imperfection on structural buckling reliability has been analyzed. And then, buckling reliability of frame structure with initial geometrical imperfection has been studied by the critical combination loading distribution. Structure BCPL buckling safety margin equation with the variable of non-dimensional imperfection amplitude is derived finally.