A BASIC STUDY ON A HYBRID STRUCTURE CONSISTING OF CABLES AND RIGID STRUCTURES
Minger WU, Yasuhiko HANGAI and Hiroshi OHMORI
Department of Architecture
In the paper, a new type of hybrid structure consisting of cables and rigid structures is proposed. In the hybrid structure, cables are used as tensile members, rigid structures are used as compressive members. Rigid structures in the hybrid structure may have arbitrary shapes, such as lines, circles, cubes, and so on. Initial stress is introduced in the system to provide enough geometric stiffness, so that the proposed hybrid structure is named "Hybrid Structure Stabilized by Tension".
In the first step of the paper, kinematic relations and equilibrium relations are formulated for cables and rigid structures and then for the hybrid structure. The kinematic equations and the equilibrium equations are called basic equations. In the basic equations, the degrees of freedom of rigid structures are not considered by using the displacements of the centers of gravity as usual, but by using the displacements of the nodes on their surfaces which are connected with cable members. To this end, generalized inverse is effectively used in the paper.
By using these basic relations, the following items about the hybrid structure are studied.
(1) Classification of stable and unstable hybrid structures
(2) Introduction of pre-stress for stability and initial stiffness
(3) Stress and displacement analysis under static loads
(4) Vibration analysis
(5) In order to examine the validity of the theoretical analyses, experiments on a hybrid structure model are done as follows: i) the introduction of pre-stress, ii) static loading experiment
Keywords: hybrid structure, tension structure, cable structure, rigid structure, generalized inverse, equilibrated stress, pre-stress introduction, stability, static analysis, vibration analysis