External explosion-induced collapse failure mechanism on single-layer reticulated domes

The blast performance of single-layer reticulated domes was studied to reduce the external explosion-induced collapse failure and mitigate the damage on indoor equipment and people. A numerical model for the collapse of single-layer reticulated dome structures by considering both the initial static loading and the blast loading is proposed. The proposed numerical model was verified by comparing the predicted results with the test results obtained from dynamic tests on single-layer reticulated dome structures. Four collapse modes are identified from the curves of response indexes versus the nominal scaled distance and the shape of deformation, namely inclined-plane collapse, concave-bowl collapse, elliptic-ring collapse, and S-bend collapse. The response curves of the dimensionless characteristic response can be divided into two clusters in the full load domain, which correspond to dynamic instability failure and strength failure, respectively. The inclined-plane collapse, concave-bowl collapse, and elliptic-ring collapse modes are dominated by dynamic instability, and geometric and material nonlinearity cause an abrupt collapse. In contrast, the S-bend collapse mode is dominated by strength failure, where gradual stiffness weakening causes a slow collapse. Based on the structural response performance before collapse, an empirical expression of damage factor is formulated, which could be further service in the structural damage evaluation.