PSI - Issue 84

Available online at www.sciencedirect.com

ScienceDirect

Procedia Structural Integrity 84 (2026) 1103–1110

© 2026 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Conference Keywords: Locked coil and parallel wire cables; vortex induced vibrations;rain-wind vibrations; cable damping. Abstract This paper discusses wind induced vibrations observed for vertical locked-coil or parallel wire hanger cables of contemporary suspension bridges. It is demonstrated that these types of hanger cables are characterized by very low structural damping levels at all frequencies, being the fundamental prerequisite for the development of vibrations. Due to the nature of vortex shedding and the closely spaced natural frequencies of taut cables, vortex induced vibrations can be expected for the full range of wind speeds. Rain wind induced vibrations of vertical hanger cables have been observed in the field as well as in wind tunnel tests. The strength of rain-wind excitation is considerably stronger than that due to vortex shedding yielding larger vibration amplitudes thus requiring more added damping for mitigation. 1. Introduction Hanger cables in suspension bridges are important vertical structural elements which transfer the dead and live loads of the bridge girder to the main cables. Over time various designs of the hangers and anchorages have been favoured. The hangers of older suspension bridges such as the Golden Gate Bridge or Forth Road Bridge, are composed of stranded wire loops set into grooves in the cable bands and attached to the deck top chord by means of threaded bolts. Newer hanger designs feature locked coil or parallel wire strands painted or sheathed by high density polyethylene coating. The cable ends of the newer type hangers are commonly attached to the cable bands and deck III Fabre Conference: Existing Bridges, Viaducts, and Tunnels: Research, Innovation, and Applications Wind induced vibrations of suspension bridge hanger cables Allan Larsen a, * a COWI consulting engineers, Parallelvej 2, Kgs. Lyngby, Denmark

* Corresponding author. E-mail address: aln@cowi.com

2452-3216 © 2026 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Conference 10.1016/j.prostr.2026.06.141