An improvement of the stiffness modification method to find bifurcated paths at a multiple bifurcation point

Stifiness modification method is presented as a strong and pertiiieiit uieaiis for the hifurcatioii aiialysis at a multiple bifiircatioii pomt with multiple critical eigeiivectors. It hitherto has heel problematic to fiuicl the directions of bifurcated paths with reference to the critical eigellvectors whell the multiplicity is large. In order to resolve this problem, we revise the stifiness modlificatioll method, which is a systematic method to modify the entries in a few rows and columns of the tangent-stifiness matrix to reduce the symmetry of the system. The moclificationi is coildluctedl so as to reduce the apparent geometrical symmetry. aiicl. iii tunii, to obtam the critical eigeiivectors correspolldliiig to the clirectioiis of bifurcated paths. The validity aiicl usefuliiess of the present method improved hereiii are eiisurecl by systematically obtaiiiiiig a complete set of bifurcated paths of regular polygonal truss domes awl hoiieycomb structures.