Purpose: In order to optimize SCSWIRC, the simplification and further optimization method is proposed. SCSWIRC's optimization includes two levels. The first level refers to simplifying structural system from the perspective of components; the second level refers to optimizing components' sectional areas from the perspective of mechanics. The first level aims to remove redundant components, and the second level aims to reduce structural self-weight based on the first level. The purpose of the paper is to simplify SCSWIRC's structural system and optimize structural self-weight and reduce construction forming difficulty.Design/methodology/approach: Grid-jumping layout and multi-objective optimization method is used to simplify and further optimize Spatial cable-truss structure without inner ring cables (SCSWIRC). Grid-jumping layout is used to simplify remove redundant components, and multi-objective optimization method is used to reduce structural self-weight. The detailed solving process is given based on grid-jumping layout and multi-objective optimization method.Findings: Take SCSWIRC with a span of 100m as an example to verify the feasibility and correctness of the simplification and further optimization method. The optimization results show that 12 redundant components are removed and the self-weight reduces by 3.128t from original scheme to grid-jumping layout scheme 1. The self-weight reduces from 36.007t to 28.231t and feasible coefficient decreases from 1.0 to 0.627 from grid-jumping layout scheme 1 to multi-objective optimization scheme. The simplification and further optimization can not only remove the redundant components and simplify structural system to reduce construction forming difficulty, but also optimize structural self-weight under considering structural stiffness to reduce project costs.Originality/value: The proposed method firstly simplifies SCSWIRC and then optimizes the simplified SCSWIRC, which can solve the optimization problem from the perspective of components and mechanics. Meanwhile, the optimal section solving method can be used to obtain circular steel tube size with the optimal stiffness of the same areas. The proposed method successfully solves the problem of construction forming and project cost, which promotes the application of SCSWIRC in practical engineering.

Based on annular crossed cable-truss structure model with diameter of 17.15 m, the type of membrane roof was first studied. Two membrane roof schemes, cable-supported membrane roof and skeleton-supported membrane roof, were proposed. The form-finding analysis of two types of membrane roof structures was carried out. By comparative study, the strengths and weaknesses of two schemes were given, and the feasibility of skeleton-supported membrane roof was demonstrated. Second, skeleton-supported membrane roof was studied by collaborative form-finding and non-collaborative form-finding. The form-finding method being suitable for the structure was given. Finally, load analysis, parametric analysis, and dynamic characteristics of membrane and non-membrane roof structures were carried out. The results show that skeleton-supported membrane roof has the strength to resist to external loads. Poisson’s ratio and self-weight have little influence on membrane roof, and arch height and pretension of membrane surface have great influence on membrane roof. The vibration modes of structure are mainly manifested as up and down vibrations accompanying with local torsion of planar cable-truss frame, which is not bad for overall structure. Meanwhile, film-covering effects of annular crossed cable-truss structure are obvious. The study contents have promoted the application of annular crossed cable-truss structure in practical engineering.

To overcome the weak lateral stiffness and weak anti-collapse ability of traditional spoke cable-truss structures, the crossed spoke cable-truss structure (CSCTS) is proposed. As structural stiffness and bearing ability are generated from prestresses produced by tensioning cable length, it is necessary to study the influences of manufacturing errors on CSCTS. The structural design method is proposed by theoretical derivation and the finite element (FE) model with a span of 100 [ ] is designed for CSCTS. The influences of manufacturing length errors on the mechanical behaviors of CSCTS are studied under four different conditions based on FE model. The influences of manufacturing length errors on the static behaviors of CSCTS are further studied under full-span and half-span loads. Then the control criteria of cable length errors are obtained by theoretical method under the same and different manufacturing length errors. The results show the structural design method can solve the reasonable shape and self-stress mode of CSCTS. The influences of the elongation or shortening of cables and struts on the sensitivity indexes of CSCTS are equal. The internal force variations are the same under different prestress states when length errors are unchanged. Manufacturing errors have greater influences on cable-truss frame itself than others. The influences of manufacturing errors at different positions on internal forces are similar under full-span and half-span loads, which is more sensitive to half-span loads. When construction method of un-adjustable cable length is used, the reasonable control criteria of cable length errors can be adopted considering calculation amount and project costs. The contents can support some meaningful references for the design and construction of CSCTS.

Spatial cable-truss structure without inner ring cables (SCSWIRC) is a new type of cable-truss tension structures (CTTS), and its anti-collapse ability is strong, but its construction forming is difficult. The main reason is that there are a lot of struts (or compression struts) when the span of SCSWIRC is larger and struts are easy to cause winding and collision during its construction. In order to solve the difficulty of construction forming, the grid-jumping layout was proposed to simplify SCSWIRC to delete the redundant struts. It is necessary to further study whether the anti-collapse ability of the remaining structure after the grid-jumping layout is affected by grid-jumping layout. Based on transient dynamic theory, the rupture of local cables (struts) of SCSWIRC with grid-jumping layout is studied. The research results show that self-weight has a little influence on the SCSWIRC; the initial prestress only increases the internal forces of components and the same proportion of feasible prestress levels do not amplify the response of SCSWIRC with rupture of local cables (struts); the anti-collapse ability of the remaining structure after the grid-jumping layout of SCSWIRC is still strong and the ability to resist the external loads is good at the same time. The rupture of local cables (struts) for the original scheme and grid-jumping layout schemes do not cause the progressive collapse. The research contents offer useful reference for the safety design of SCSWIRC.