Stability and Adequate Bracing Design of Pretensioned Cable-Braced Inverted-Y-Shaped Ferris Wheel Support System Using Matrix Structural Second-Order Analysis Approach

Abstract

Elastic buckling and second-order analyses are conducted using the matrix structural analysis approach for the in-plane and out-of-plane stability and adequate bracing design of a new type of Ferris wheel support system that can be used to allow a large span: the pretensioned cable-braced inverted-Y-shaped support system (PCB-IYSS). First, the global structural stability stiffness matrix is formulated by combining the element stability stiffness matrices and considering the lateral bracing stiffnesses of the cable system. In the elastic buckling analysis, the eigenproblem is solved by setting the determinant of the global structural stability stiffness matrix to zero. The influence of the lateral bracing stiffness on the buckling load and economical efficiency of the columns are discussed. In the second-order analysis, the element end displacements and reaction forces are determined considering the lateral loads at the top of the column. Finally, using the results from these analyses, the adequate bracing approach is followed for the design of PCB-IYSS. The strength limits of the cable system (as column-top lateral bracing) and supporting columns (as column-base in-plane rotational spring-supported bracing) are formulated, and their adequate stiffness requirements are determined based on examination of the strength limits. A detailed design procedure and an elementary design example are presented.