System solutions study on the fatigue of the fast cable-net structure caused by form-changing operation

TL;DR

This paper investigates the fatigue issues of FAST's cable-net structure caused by form-changing operations, proposing deformation strategies, estimating operational trajectories, and developing a new steel cable system to enhance durability.

Contribution

It introduces a new deformation strategy, estimates the telescope's operational trajectory, and develops a novel steel cable system to improve fatigue resistance.

Findings

Reduced stress amplitude through optimized deformation strategy

Estimated telescope tracking trajectory for fatigue assessment

Developed a new steel cable system meeting fatigue requirements

Abstract

The Five-hundred-meter Aperture Spherical Radio Telescope (FAST) is supported by a cable-net structure, whose change in form leads to a stress range of approximately 500MPa. This stress range is more than twice the standard authorized value. The cable-net structure is thus the most critical and fragile part of the FAST reflector system. In this study, we first search for a more appropriate deformation strategy that reduces the stress amplitude generated by the form-changing operation. Second, we roughly estimate the tracking trajectory of the telescope during its service life, and conduct an extensive numerical investigation to assess the fatigue resistance requirements. Finally, we develop a new type of steel cable system that meets that cable requirements for FAST construction.