The common design structures of Ferris wheels are rigid, flexible, and rigid-flexible hybrid structures.
The original Ferris wheel is made of rigid trusses, but the rigid Ferris wheel is relatively heavy, which limits the possibility of further expansion in size. Flexible ferris wheels and rigid-flex hybrid Ferris wheels are more common in huge Ferris wheels. They have lighter weight, slender cables, so the architectural effects are more favored by architects.
The design structure of the Ferris wheel is mainly composed of a bracket and a spoke structure. The spoke structure is placed vertically, the central axis is supported by the space support frame, and the rim (ie, the outer ring) is mechanically driven to rotate around the central axis, which form the Ferris wheel.
When the rim structure is a plane steel truss, based on the convenience of connection, the structure of the spokes generally adopts a radially arranged flat steel truss system, and the spokes are connected by several steel trusses with smaller diameters to increase rigidity of the spokes, improve the stability of the structure, so this Ferris wheel design structure is rigid.
When the rim structure is a triangular spatial steel truss, taking into account the connection structure of the spokes and the rim, there are usually two structural forms of the spokes: the all-steel cable system and the steel truss and the steel cable spacing system, forming flexible Ferris wheel and rigid-flex hybrid Ferris wheel structure separately.
The supporting structure system of the Ferris wheel was first supported by steel trusses, but now most of them use A-shaped trusses, which form a rigid force system in the plane. Cables are arranged on the outside of the two A-shaped supporting frames to ensure the stability of the structure.
The drive system of the Ferris wheel design structure drives the rim to rotate through friction, and there is also a braking system simultaneously to ensure that the Ferris wheel can be stopped in time in an emergency. From the perspective of force, the drive system can be regarded as the constraint of the tangent direction of the rim. When the out-of-plane deformation of the rim becomes large, it can be considered that there is still a certain out-of-plane constraint in the drive system. The loads that the Ferris wheel design structure bears mainly include cable prestress, deadweight load, braking force, wind load and snow load.
In general, the first-order buckling mode of the Ferris wheel design structure is the out-of-plane bending buckling of the rim.