Test method and device for monitoring steel wire fretting fatigue state

Abstract

The invention discloses a test method and a device for monitoring a steel wire fretting fatigue state. The device comprises a base, a support column, a top beam, a hydraulic lifting platform and a horizontal loading device. The test method comprises the following steps that two ends of a tested steel wire passing through the horizontal loading device are fixed respectively; the tested steel wire is stretched until the tested steel wire bears a preset initial load; the horizontal loading device is moved so that loading steel wires in the horizontal loading device compress tightly the tested steel wire; the hydraulic lifting platform is controlled to move up and down to apply alternate loads to the tested steel wire; the tested steel wire generates fretting fatigue; a tangential force is transmitted to a spoke-type pull-press sensor through an internal thread connecting rod arranged on a loading block, wherein an acoustic emission sensor is arranged on an upper grip block of the top beam; and the test is stopped when the tested steel wire is broken because of fretting fatigue. The device can dynamically record a tangential force between contact steel wires and tested steel wire acoustic emission signals in an experimental process, and provides an effective basis for research on a steel wire fretting zone, crack generation and fracture mechanisms of a fretting zone, and influences of the crack generation and the fracture mechanisms on a fretting fatigue life. The device has a simple structure, is convenient for operation and has good effects.

Description

technical field [0001] The invention relates to a test method and a device, in particular to a test method and a device suitable for dynamically monitoring the fretting fatigue state of a steel wire. Background technique [0002] Steel wire rope has good bending flexibility and load-bearing capacity, so it is widely used as traction cable for transportation machinery, hoisting cable for mining machinery, support cable for passenger cableway, load-bearing steel cable for cable-stayed bridge, etc. The bearing strength and service life of steel wire rope Longevity is very important to the safe operation of these application equipment. During the operation of these equipment, the steel wire rope is subject to repeated stretching and bending and dynamic loads, so that the internal strands of the steel wire rope and the steel wires in the strands are subject to fretting wear of different fretting amplitudes, and they must also withstand alternating stress. Smaller fretting ampli...

AI Technical Summary

Problems solved by technology

[0003] At present, the test methods and devices used for fretting fatigue include: Patent No. 200810304928.3 discloses an axial fatigue test method and device for applying superimposed wear loads to large-diameter shaft test pieces. The cause of fatigue fracture and life prediction of specimens under wear load and fatigue load are helpful, but this experimental device is suitable for shaft specimens; a steel wire fretting fatigue testing machine disclosed in patent numbers 200910182122.6 and 200920233073.X can only examine The influence of different fretting fatigue parameters on the fretting fatigue life of steel wire cannot study the fretting fatigue failure mechanism of steel wire. During the experiment, the contact load between steel wires changes due to fretting wear; the patent No. 201020135448.1 discloses a The fretting fatigue testing machine uses two indenters to simulate the actual fretting conditions of the component, and conducts the fretting fatigue damage test of the block specimen with the spatial displacement of the two indenters, but this experimental device is only suitable for block specimens

However, in the course of the experiment, the contact load between the steel wires can be kept constant, the tangential force between the steel wires, the acoustic emission behavior of the steel wire and the displacement amplitude can be monitored in real time, and the influence of the fretting fatigue parameters on the fretting fatigue life of the steel wire can be investigated. The steel wire fretting fatigue test method and device have not yet

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