NUMERICAL NONLINEAR-ANALYSIS OF SECONDARY BUCKLING IN STABILITY PROBLEMS

In this paper we discuss the numerical calculation of secondary buckli ng of structures. This kind of stability problem contains two paramete rs (one is conservative load parameter, the other is auxiliary one) an d satisfies Z(2)-symmetry. By using the symmetry and introducing a new parameter we construct an augmented system. The system avoids the sin gularities of usual ones. Adjusting the newly introduced parameter, on e can calculate a double buckling load and two corresponding buckling modes, secondary buckling load and secondary buckling mode directly wi thout tracing primary post-buckling path. Here, the use of the augment ed system yields a quadratically convergent iteration scheme. We also discuss the implementation of Newton's method solving the system - a p artitioning procedure. With this algorithm the amount of computation i s largely saved.