STUDY ON FORCE MECHANISM OF CABLE-TRUSS FRAME AND JUMPED LAYOUT OF ANNULAR CROSSED CABLE-TRUSS STRUCTURE

A new type of cable-strut tension structure named Annular Crossed Cable-truss Structure(ACCTS) comprises a series of planar cable-truss frames crossed each other. To investigate the force mechanism of ACCTS, a cable-truss frame model with 2-bar and 6-cable has been developed, and its initial stiffness formula has been derived as well. The model is further simplified to make it is upper and lower vector heights equal, and then the initial stiffness formula and the critical slack load formula are further deduced. Based on ANSYS software and cable-truss frame with a span of 60m, the influences of the number of struts and position of jumped layout on the cable-truss frame are studied. According to the former 60m span cable-truss frame's research results, the jumped layout of ACCTS with a span of 100m is studied. The static and dynamic performances of two schemes, the optimal jumped layout scheme and the original scheme, are systematically studied. It is shown that the number of struts would be about 6~8 for the planar cable-truss frame and the optimal order of jumped layout is strut 6-7→strut 4-5→strut 2-3. The optimal order of jumped layout of ACCTS agrees with that of the cable-truss frame, verifying the feasibility of conclusions. In the condition of no variation in the original structure's static and dynamic performance, the optimal scheme of the jumped layout will lower the steel consumption and enhance the buckling loads. Moreover, it also simplifies structure for easy construction.