Study on the collapse performances of fabricated single-layer spatial network structures based on discrete beam elements

Abstract

Using discrete beam elements to simulate the mechanical properties of assemble joints, the collapse performances of free-form, cylindrical, and K6 spherical surface latticed shells were analyzed. The effects of grid sizes, rise-span ratios, and connection behaviors on structural collapse performances were discussed. The main conclusions were obtained: (1) By conducting an integral scaled model test of a free-form latticed shell, the accuracy of the collapse analysis model with discrete beam elements was verified. (2) Multiple collapse shapes were obtained for the latticed shells with various structural parameters. To ensure an excellent collapse-resistant capacity, the grid size should not exceed 4 m, and the rise-span ratio is suggested as 1/4 for the cylindrical latticed shells, and the grid size should not be greater than 3 m, and the rise-span ratio should not be less than 1/4 for the spherical surface latticed shell. (3) The connection behaviors of assemble joints significantly influence the structural collapse-resistant capacity. When the stiffness and bearing capacity of the assemble joint drop to 50% of the joint designed based on “strong joints and weak tubes”, the robustness index decreases rapidly. However, more than 80% of the collapse load is still reserved for the cylindrical latticed shell and approximately 60% for the spherical surface latticed shell.