Failure Mechanism Of Single-Layer Latticed Domes With Damage Accumulation Under Earthquakes

With the development of the society, the reticulated shells are uesd widely more and more because of its good mechanics performance and large span. It won much attention in all over the world as a popular space structure. By the researcher's hard work, dynamic behaviors of latticed domes under frequent and occasional earthquakes have been fully understood, but the failure mechanism of reticulated shells under severe earthquakes is still at the exploratory stage. There is not satisfactory theory for anti-seismic design up till now, therefore, advanced development of reticulated shells is hindered by this reason.Due to these practical problems, in this paper, based on the other scientists'study, the dynamical performance of reticulated domes is studied systemically, the damage model and the dynamic failure distinguishing criterion of reticulated domes are proposed so as to be used for the performance-based seismic design .The two types of failure modes of single-layer reticulated domes subjected to harmonic load are illustrated. The whole course of characteristic responses with different load intensity is described in detail. Based on the understanding of the dynamic performance of the single-layer reticulated domes, the fuzzy synthetic evaluation method is used to distinguish the two types of failure modes, it is probative that it is a good method for the study on the failure modes of reticulated domes under severe earthquakes.Large-scale parameter analysis for single-layer reticulated domes with damage cumulation and the regularity of multiple characteristic responses of domes with different parameter is discussed, the influences of the changing of ratio of rise to span, various weight of roof, span, geometric imperfection on failure mechanism are fully discussed. After distinguishing the two types of failure modes of domes under severe earthqukes by the fuzzy synthetic evaluation method from the summary of responses at ultimate state in many examples, the damage model with damage cumulation and with original imperfection are proposed. Based on the structural damage index cases, the dynamic failure distinguishing criterion is established, which can be used to estimate the damage of the structure and distinguish the the corresponding ultimate load intensity under random dynamical load.In addition,a 180m single-layer reticulated domes is be simulated, its anti-seismic performance under frequent,occasional earthquakes and severe earthquakes are fully disussed, the influence of the section of beam, original imperfection, and input of earthquakes to performance of domes are compared, which can be consulted for design in the future.