Retrofitting of hybrid cable domes against strut buckling using di-pyramid (DP) module and force-limiting devices (FLD)

Cable domes are one of the most efficient types of long-span structures designed using the concept of tensegrity structures. They maintain the stability by being attached to compression concrete ring at the boundaries which contradicts the free-standing principal of tensegrities. In this paper, a hybrid cable-dome is presented as a combination of a Levy-type cable dome and a real tensegrity ring instead of the concrete. Two different configurations based on different angles of modules in the tensegrity ring were selected and the application of two strategies were investigated, namely, di-pyramid (DP) module and force-limiting devices (FLD) instead of critical struts, to strengthen hybrid cable domes. Effect of the tensegrity ring and its combined performance with the cable dome were evaluated by performing static and dynamic collapse analyses on the hybrid and traditional cable domes. The results demonstrate that the load-carrying capacity of suggested hybrid cable domes equipped with DP modules and FLDs can be increased up to almost 100%. •In this paper, a new hybrid cable–strut system including a traditional levy-type cable dome and a tensegrity ring assembled by semi-regular modules has been considered.•In first phase of paper, collapse behavior of traditional cable dome and two hybrid system with different angles of tensegrity ring were investigated through nonlinear static and dynamic collapse analyses.•In the second phase, using of three different force limiting devises (FLDs) and also DP cable–strut modules, collapse behaviors of studied structures were improved during three step of retrofitting process.•Presence of tensegrity ring in the hybrid structures causes increasing of load-carrying capacity for two symmetric and asymmetric loading cases in comparison to traditional cable dome. Also, it changes the collapse mechanism from “overall collapse” in traditional cable dome to “local collapse with snap-through” in hybrid structure. This is a significant advantage for the proposed hybrid structure.•Using of FLDs and DPs, increase load carrying capacity of all studied structures in three steps of retrofitting. This increase is less than 5% in traditional cable dome in first step; But reaches to 35% in hybrid structures. After three step of retrofitting, load-carrying capacity of proposed hybrid structures increases up to 100%.•Considering costs of the retrofitting by FLDs, this process is usually carried out in only one step. Due to considerable incre