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.

Form-finding analysis of cable-membrane tensile structure with outer ring truss

For a flexible tension structure, the first thing to do is to perform a form-finding analysis to obtain a reasonable initial state of the structure. The initial state includes the structure's own weight and the cable force distribution under the additional dead load and the corresponding geometric configuration. The geometric configuration and expectations must be ensured to be consistent with the geometry of the building. This paper used the MIDAS software to first establish the zero-state model of the structure, and then added reasonable prestress to ensure that the initial configuration of the structure under prestress, structure dead weight and additional dead load is basically the same as that under zero state, thus ensuring the feasibility and accuracy of later structural load analysis and construction process analysis, and providing ideas and methods for related projects.

Stress Performance Analysis on a New Type of Flexible Suspension Tension Structure

A new type of flexible suspension tension structure (FSTS) is presented in this paper, which has the advantages of high-efficiency, convenient construction and wide application sphere, and it is also a kind of green and low carbon structure. In order to investigate the mechanical behavior of FSTS under the vertical load, series of structures under 10 groups of upward loads and 8 groups of downward loads are calculated with the matrix analysis method. The results show that the passive tensions of cables and displacement in the middle of span present approximate linear features under the downward loads. However, there are double broken linear features in FSTS under the upward loads. So this regularity can be utilized for the simple analysis and two-stage design calculation. Finally, the reliability of FSTS with the initial tension is investigated with the interval method. 81 kinds of structures with different initial tension are calculated, and the influence regularity of the initial tension in the back cable and the bottom cable are given. It is found that the deformation of FSTS is more sensitive to the initial tension of cables. Consequently, the initial tensions of cables are dominated by deformation of structures under design and construction.

On divided difference operators in function algebras

In this paper we study divided difference operators of any order acting in function algebras. In the definition of difference quotient operators we use a tension structure defined on the set of points on which depend the functions of the algebras considered. In the paper we mention the oportunity for partial difference quotient operators as well as for some purely algebraic definition of divided difference operators in terms of the suitable Leibniz product rules.