**A BASIC STUDY ON A HYBRID STRUCTURE CONSISTING OF CABLES
AND RIGID STRUCTURES**

*Minger WU, Yasuhiko HANGAI and Hiroshi OHMORI*

Department of Architecture

Abstract

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