The Nonlinear Finite Element Analysis Of Cable-strut Tensile Structure

As a novel and original structure, the cable-strut tensile structure has fine performance, so it is more and more in people's graces. The cable-strut tensile structure has been demonstrated the huge vitality and the broad application prospect by the widespread application in many kinds of buildings. At present, our country and other countries have obtained some positive results in the theory and practice of the cable-strut tensile structure. Until now the cable-strut tensile structure which realizes in the project mainly is the cable dome structure. Cable dome structure works mainly as the roof part of a building. It is composed of cable, compression strut, central tension loop and surrounding compression ring. Our country starts this research in recent years and has yielded some gradual results. Generally speaking, our achievements are insufficient to the comprehensive theory.This article first described the development history and the present situation of the cable-strut tensile structure, then illuminates its main structural style - cable dome structure and the characteristic. On the foundation of reading widespread literatures, this article introduces the main cable unit models and compares the advantages of these unit models. Literature [23] and literature [24] propose four-node isoparametric cable finite element model which has high precision and succeeds in the single cable structure and cable net structure. In this paper, a mixed finite element model combining the four-node isoparametric cable element and two-node straight line element is presented. Two-node straight-line element simulate compression strut and four-node isoparametric cable element simulate cable. The purpose of this paper is promoting the four-node isoparametric cable element theory to the research of cable-strut tensile structure.As a flexible tensile structure, without pre-stressing the cable-strut tensile structure dose not have stiffness. The first work of this paper is form-finding whose assignment is seeking the reasonable structure geometry and the pre-stressed distribution. The second kind form finding of cable-strut tensile structure has the same result with the pre-stressed distribution. Specially, when the pre-stressed value is quite small, their results closely coincide. The second step is the static analysis by which we can judge structure's security and count its internal force and displacement. This article researches the stress distribution and displacement change under the different loads, which prove that cable dome as a representative form of the cable-strut tensile structure has a force transmission way. The internal force transfers by ridge cable from inner to outer. The dynamic performance mainly describes with the structure's base frequency. Finally, the article computes the natural frequency of the single cable structure and the cable dome structure. Their natural frequencies are small and high rank frequencies distribute thick and fast. Above research work is based on four-node isoparametric cable finite element model theory. This paper uses the Fortran95 standard language to establish finite element procedure. The comparison of certain examples which indicate that the finite element model of this paper has the good precision ,so it is suitable for the nonlinear analysis of the cable-strut tensile structure and other great span structures.