外文翻译-弯曲的金属疲劳试验的钢丝绳飞机救援起重机说明书.pdf

Engineering Failure Analysis 10 (2003) 223–235
ate/engfailanal
Bending fatigue tests on a metallic wire rope for
aircraft rescue hoists
Marco Giglio*, Andrea Manes
Department of Mechanics, ico di Milano, Via La Masa 34, 20158 Milan, Italy
Received 29 July 2002;accepted 24 August 2002
Abstract
During normal operation, the ends of helicopter rescue hoist ropes, to which a hook is attached, can be subject to
bending stress caused by vibrations. This happens in the event of partial or total recovery of the hook into its lodging
without a spring-loaded blocking system. The swinging of the rope end consequently causes bending of the rope near
the terminal, with resultant fatigue stress that can lead quickly to breakage or damage of the rope. A series of alter-
nating bending fatigue tests using a constant load, similar to those known as BoS (bending over sheave) tests, were
carried out. These simulate the effective working conditions of a rescue hoist. This paper describes modifications to test
machinery, the test method and the data obtained;statistical analysis of this data enabled us to make a rope life pre-
diction which was then experimentally confirmed by run-outs on test ropes.
# 2002 Elsevier Science Ltd. All rights reserved.
Keywords: Wire ropes;Sheave: Fatigue;Hoists;Aircraft
1. Introduction
Wire ropes, like ropes in general and also chains, monly used for traction load transmission.
Despite its widespread use, wire rope remains an plex and little-known piece of equipment.
Its construction, the considerable and diverse internal contact forces, the wear due to these forces and to
contact with drums, pulleys or sheaves, all make pletely analytical approach to reliability extremely
difficult.
Even today, experimental testing plays an important role in the analysis of rope subjected to a particular
load, especially as regards fatigue analysis where the breaking of strands results from varying types of test
and load. The purpose of this