Buckling Behavior of Square‐and‐Diagonal Double‐Layer Grid

Abstract

Square‐and‐diagonal double‐layer grids mean both “square‐on‐diagonal” and “diagonal‐on‐square” grids. When the grids are pin‐jointed, they may give rise to unstable higher‐order deformations corresponding to the unstable mode due to the relative rotations of pyramidal units. In practical design, the unstable deformations are often restrained by boundary members and so forth. The buckling behavior and the effects of boundary members are experimentally and theoretically studied in this paper for grids constructed by a bolted jointing system. In the analysis, a member model consisting of a uniform member, rigid end parts and rotational springs is used. As a result, it is found that the unstable deformations appear in the buckling mode of diagonal‐on‐square grids, but do not clearly appear in the case of square‐on‐diagonal grids. The boundary members are effective for the buckling load of diagonal‐on‐square grids, but not effective for square‐on‐diagonal grids. The postbuckling behaviors of the two grids are clearly shown experimentally.