INITIAL IMPERFECTION SENSITIVITY ANALYSIS OF MEMBRANE BUCKLING BASED ON DIRECTLY DISTURBING METHOD

Directly disturbing method was established in this paper for numerical analysis of membrane wrinkles. The disturbance applied was timely removed during analysis to analyze the flaw sensitivity of membrane post-buckling patterns. Results show that wrinkling patterns present relative stability and fixed number of wrinkles without initial flaw in the process of membrane post-buckling. The wrinkling amplitude increases with the increase of shear displacement and the buckling balance path shows stable bifurcation buckling. However, membrane wrinkling patterns will be unstable and new wrinkles will be generated during post-buckling with the combination of more complicated post-buckling balance path if initial flaw is not removed, which indicates that membrane post-buckling patterns are sensitive with the initial flaw applied and the flaw will affect the membrane buckling patterns as well as the balance path. Wrinkling patterns from both experimental results and directly disturbing method were ideally coincident which verified the directly disturbing method.