Conversion from imperfection-sensitive into imperfection-insensitive elastic structures I: Theory

A qualitative improvement of the initial postbuckling behavior of imperfection-sensitive elastic structures is their conversion into imperfection-insensitive structures by means of modifications of the original design. Such a conversion is restricted to symmetric bifurcation. Koiter’s initial postbuckling analysis is applied in the framework of the FEM to deduce mathematical relations for the transition from imperfection sensitivity to insensitivity, which may be achieved by additional supports of the structure. This conclusion as well as several other conclusions from the theoretical investigation reported in Part I of this paper are corroborated by the results from a comprehensive numerical investigation documented in Part II of this work.