Stability of Lattice Structures Under Combined Loads

The stability of elastic structures under multiple independent loads is considered. Interaction effects of the independent loading parameters are examined in terms of stability boundaries, which separate regions of stable and unstable load combinations in the load space. The convexity properties of these stability boundaries are discussed in general, both for linear and nonlinear systems. A reticulated dome subjected to vertical loads is then analyzed numerically. The dome exhibits nonlinear prebuckling deformations. Static perturbation and nonlinear programming methods are utilized to compute buckling loads. Results are presented for two and three independent load configurations, and the characteristics of the stability boundaries are discussed. Finally, the interactions for the reticulated dome are compared to those for shallow arches.