WO2020206829A1

WO2020206829A1 - Fretting fatigue test apparatus and method for steel wire under radial impact condition

Info

Publication number: WO2020206829A1
Application number: PCT/CN2019/090617
Authority: WO
Inventors: 王大刚; 朱辉龙; 张俊; 高文丽; 张德坤; 张春雷; 谭佃龙; 邱从怀
Original assignee: 中国矿业大学
Priority date: 2019-04-08
Filing date: 2019-06-11
Publication date: 2020-10-15
Also published as: CN109900566B; CN109900566A

Abstract

A fretting fatigue test apparatus and method for a steel wire under a radial impact condition. The test apparatus comprises a test bench (16) and an axial steel wire (14); the two ends of the axial steel wire (14) are separately provided with a steel wire tensioning and stretching device; the middle position of the axial steel wire (14) is provided with a radial contact device, an impact device, and a spring reset device; by making the axial steel wire (14) radially contact with a contact steel wire (17), an impact condition is simulated, the contact portion of the axial steel wire (14) is radially impacted, an impacted radial contact device is reset, the same contact position is repeatedly impacted, and impact displacement is measured by means of a displacement sensor (15). The axial steel wires (14) on steel wire fixing clamps (4) are symmetrically and parallelly assembled so as to meet a contact condition; the contact between the steel wires is guaranteed by the tension force of the spring of the spring rest device; by adjusting a distance between the spring (8) and a guide rail sliding block (9), the tension force of the spring contacting with the two sides of the axial steel wire (14) can be controlled; by changing the position of the impact device, the fretting fatigue of the steel wire can be researched under the impact states of different positions.

Description

Device and method for fretting fatigue test of steel wire under radial impact condition

Technical field

The invention relates to a fretting fatigue device for steel wires, in particular to a fretting fatigue test device and method for steel wires under radial impact working conditions under impact working conditions.

Background technique

Wire rope has good bending flexibility and load-bearing capacity, and is widely used in aircraft carrier arrest systems and marine moorings. There are mainly vertical landing type and blocking type on the carrier-based aircraft landing aircraft. Because vertical landing type fighters have disadvantages such as fuel consumption and shortening the combat radius, the blocking system has become the most important landing method. The speed of carrier-based aircraft can reach 220km/h-280km/h when landing, so the wire rope is the main load-bearing component of the arrest system. The service life and load-bearing strength of the wire rope are of great significance for the safe landing of the carrier-based aircraft. When the arresting cable prevents the landing of the carrier aircraft, the wire rope is subjected to radial impact load and bending load, which in turn leads to the combined effect of the impact load, fatigue tension, and fatigue bending stress of the steel wire inside the wire rope. The contact load and relative slip between the steel wire and the steel wire, that is, the fretting fatigue phenomenon of the steel wire under impact conditions, leads to the initiation, propagation and final fracture of the steel wire, which seriously affects the fatigue strength and service life of the arresting cable.

There are many kinds of test devices for fretting fatigue. Patent No. 200810304928.3 discloses an axial fatigue test method and device for applying superimposed wear load to the test piece. The wear load device of the reducer structure is used to apply wear load to the components at the same time. And fatigue load; Patent No. 200910182122.6 discloses a steel wire fretting fatigue testing machine and method. A load load is applied to the axial steel wire through a horizontal loading device, and the axial clamping, tension and compression device acts on the steel sample in the axial direction. Fatigue stress, to realize the fretting fatigue test of the fretting wear and axial fatigue stress of the steel wire sample; the patent number 201110195119.5 discloses an experimental method and device for monitoring the fretting fatigue state of the steel wire, by controlling the hydraulic lifting platform The up and down movement applies axial alternating load to the test wire, and the load load is applied to the axial wire through the horizontal loading device. The test wire has fretting fatigue, and the tangential force is transmitted to the spoke type through the internal thread connecting rod provided on the loading block. The tension and compression sensor can dynamically record the tangential force between the contact steel wires and the acoustic emission signal of the test steel wire during the experiment; the above-mentioned test devices are all aimed at the fretting fatigue test of the specimen under the axial tension. Patent No. 201410728399.5 discloses an impact friction test system for winding hoisting wire ropes in kilometer-deep wells, simulating the impact friction of winding hoisting wire ropes in kilometer-deep wells, and studying wire rope friction under different rotation speeds, accelerations, impact speeds, and contact specific pressures. Learn performance. However, none of the above devices can carry out the fretting fatigue test of the steel wire inside the wire rope under high-speed and large-load impact conditions.

Therefore, a fretting fatigue device for steel wires under radial impact conditions is provided to detect the radial impact force, radial impact displacement, axial tension, friction between steel wires and other parameters of the steel wire under impact conditions, and can evaluate the diameter The fatigue strength decline of steel wire and the evolution of remaining service life under impact conditions are of great significance to the study of how to improve the load-bearing capacity and service life of steel wire under impact conditions.

Summary of the invention

Technical problem: The purpose of the present invention is to provide a fretting fatigue test device and method for steel wire under the condition of high-speed radial impact with simple structure, simple operation and real-time monitoring.

Technical solution: The fretting fatigue test device for steel wire under radial impact conditions of the present invention includes a test bench and an axial steel wire. A steel wire tensioning device is provided at both ends of the axial steel wire. A radial contact device, an impact device and a spring return device are provided at the middle position;

The steel wire tensioning device includes an electric cylinder, a tensile force sensor, and a steel wire clamp connected in sequence. One end of the tensile force sensor is connected to the piston threaded rod of the electric cylinder, and the other end is connected to the steel wire clamp; The end of the steel wire is embedded in the steel wire clamp, which is clamped by screws through the cover plate to ensure that the axial steel wire does not slip when subjected to axial tension;

The radial contact device includes a support rail, a steel wire fixing fixture symmetrically arranged on the support rail, a fixture support and a track slider; the steel wire fixing fixture and the track slider are assembled together through the positioning hole of the fixture support; The steel wire fixing jig is symmetrically embedded with the contact steel wire in contact with the axial steel wire, and the upper and lower ends are clamped and fixed by screws;

The impact device includes an impact electric cylinder that provides impact force, a tension and compression sensor connected to the threaded rod of the piston of the impact electric cylinder, the other end of the tension and compression sensor is connected to the punch in a threaded connection, and the center of the punch is facing the steel wire Contact position; the front side of the impact device is equipped with a displacement sensor fixed on the test bench, and the measurement position is directly on the center of the fixture support;

The spring reset device includes a spring fixing block and a spring. The spring fixing block is fixed on the support rail with a screw, and the spring is fitted between the guide rail slider and the spring fixing block; the distance between the rail slider and the spring fixing block is adjusted , Can control the contact force on both sides of the axial steel wire.

The steel wire fixing fixture is formed by connecting a trapezoid-like structural block and a square plate through screws. The trapezoid-like shape has a circular groove on the plane for inserting and fixing the steel wire, and the end of the groove is provided with a through hole connecting the fixing plate.

The upper surface of the support rail at the spring fixing block is engraved with equal interval scales, which is beneficial to control the distance between the rail slider on both sides of the support rail and the spring fixing block during assembly.

To implement the test method of the fretting fatigue device of steel wire under radial impact conditions, the specific steps are as follows:

a. During the test, the axial steel wire is assembled on the steel wire tensioning device, and the electric cylinder is controlled by the controller to apply a predetermined initial tension to the axial steel wire;

b. Fix the contact wire on the wire fixing fixture and adjust the distance between the guide rail slider and the spring fixing block;

c. Zero the tension sensor, tension and compression sensor and displacement sensor;

d. The impact electric cylinder is controlled by the computer to impact the axial steel wire; the impact speed of the impact electric cylinder is changed, the output signals of different sensors are collected, and recorded on the computer to obtain the radial direction of the axial steel wire under different impact speeds. Impact force, radial impact displacement and axial tension;

e. Change the position of the impact electric cylinder and adjust the position of the radial contact device so that the center position of the punch of the impact device is directly on the contact position of the axial wire and the contact wire;

f. Repeat steps a to e to collect the output signals of different sensors and record them on the computer;

g. Compare, analyze and calculate all the data obtained, and provide a basis for the fatigue strength and fatigue life of the axial steel wire under the same impact speed at the same impact position and different impact positions.

Beneficial effects: due to the adoption of the above technical scheme, the present invention has simple structure, simple operation, and can monitor the fretting fatigue test of steel wire under high-speed radial impact conditions in real time. Through the radial contact between the axial steel wire and the contact steel wire, the impact condition is simulated, the radial impact is performed on the steel wire contact part, and the micro-moving contact device after the impact is reset to realize the repeated impact of the same contact position, which is realized by a displacement sensor Measurement of impact displacement. The steel wires on the steel wire clamps on both sides are assembled symmetrically and parallel to meet the contact conditions; the contact between the steel wires is guaranteed by the spring tension of the spring return device. By adjusting the distance between the spring and the track slider, the contact spring tension on both sides of the axial steel wire can be controlled; the position of the impact device can be changed to obtain the fretting fatigue study of the steel wire under different impact states. By detecting the radial impact force, radial impact displacement, axial tension, friction between steel wires and other parameters of the steel wire under impact, it is possible to evaluate the fatigue strength decline and the remaining service life evolution of the steel wire under radial impact conditions. How to improve the load-bearing capacity and service life of steel wire rope under impact conditions is of great significance.

Description of the drawings

Figure 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic structural diagram of the A-direction contact device in FIG. 1;

Figure 3 is a partial enlarged view of the structure of the present invention.

In the picture: 1-hydraulic cylinder, 2-tension sensor, 3-wire clamp, 4-wire fixing clamp, 5-fixture support, 6-support rail, 7-spring fixed block, 8-spring, 9-rail slide Block, 10-positioning hole, 11-tension and compression sensor, 12-impact electric cylinder, 13-punch, 14-axial steel wire, 15-displacement sensor, 16-test stand, 17-contact steel wire.

detailed description

An embodiment of the present invention will be further described below in conjunction with the accompanying drawings;

As shown in Figure 1, the fretting fatigue test device for steel wire under radial impact conditions of the present invention is mainly composed of test bench 16, axial steel wire 14, steel wire tensioning device, radial contact device, impact device and spring The reset device is composed of two steel wire tensioning devices, which are arranged symmetrically to each other. The two ends of the axial steel wire 14 are respectively fixed on the steel wire tensioning device, and the radial contact device, the impact device and the spring reset device are located At the middle of the axial steel wire 14.

The steel wire tensioning device includes an electric cylinder 1, a tension sensor 2 and a steel wire clamp 3 connected in sequence. One end of the tension sensor 2 is connected to the piston threaded rod of the electric cylinder 1, and the other end is connected to the steel wire clamp 3. The end of the axial steel wire 14 is embedded in the steel wire clamp 3, the steel wire clamp 3 is clamped by screws through the cover plate to ensure that the axial steel wire 14 does not slip when subjected to axial tension.

The impact device includes an impact electric cylinder 12 that provides impact force, a tension/compression sensor 11 connected to the piston threaded rod of the impact electric cylinder 12, and the other end of the tension/compression sensor 11 is connected to a punch 13 in a threaded manner. 13 The center position is facing the steel wire contact position; the front side of the impact device is provided with a displacement sensor 15 fixed on the test bench 16, and the measurement position is facing the center position of the clamp support 5.

As shown in Figure 2, the radial contact device includes a support rail 6, a steel wire fixing fixture 4 symmetrically arranged on the support rail 6, a fixture support 5 and a track slider 9; a steel wire fixing fixture 4 and a track slide The blocks 9 are assembled together through the positioning holes of the clamp support 5; the center of the steel wire fixing clamp 4 is symmetrically embedded with a contact wire 17 in contact with the axial steel wire 14, and the upper and lower ends are clamped and fixed by screws, as shown in Figure 3. .

The spring reset device includes a spring fixing block 7 and a spring 8. The spring fixing block 7 is fixed on the support rail 6 with screws, and the spring 8 is fitted between the rail slider 9 and the spring fixing block 7; the adjusting rail slider 9 The distance from the spring fixing block 7 can control the contact force on both sides of the axial steel wire 14.

The steel wire fixing jig 4 is formed by connecting a trapezoid-like structural block and a square plate through screws. The trapezoid-like shape has a circular groove for inserting and fixing the steel wire in the plane, and the end of the groove is provided with a through hole connecting the fixing plate.

The upper surface of the support rail 6 at the spring fixing block 7 is engraved with equally spaced scales, which is beneficial to control the distance between the rail slider 9 and the spring fixing block 7 on both sides of the support rail 6 during assembly.

The positioning hole 10 is used to fix the impact electric cylinder 12. When the impact electric cylinder 12 is assembled in different positions, the position of the radial contact device is adjusted at the same time, so that the center position of the punch 13 of the impact device is facing the wire contact position. Realize the impact test on different positions of the axial steel wire 14.

Implementing a test method for a fretting fatigue device of a steel wire under radial impact conditions according to claim 1, comprising the following steps:

a. During the test, the axial steel wire 14 is assembled on the steel wire tensioning device, and the electric cylinder 1 is controlled by the controller to apply a predetermined initial tension to the axial steel wire 14;

b. Fix the contact wire 17 on the wire fixing fixture 4 and adjust the distance between the guide rail slider 9 and the spring fixing block 7;

c. Zero the tension sensor 2, tension and compression sensor 11 and displacement sensor 15;

d. The impact electric cylinder 12 is controlled by the computer to impact the axial steel wire 14; the impact speed of the impact electric cylinder 12 is changed, the output signals of different sensors are collected, and recorded on the computer to obtain the axial steel wire 14 under different impact speeds. Radial impact, radial impact displacement and axial tension received;

e. Change the position of the impact electric cylinder 12 and adjust the position of the radial contact device so that the punch center position of the impact device is directly opposite to the contact position of the axial steel wire 14 and the contact steel wire 17;

g. Compare, analyze and calculate all the data obtained, and provide a basis for the fatigue strength and fatigue life of the axial steel wire 14 under different impact speeds at the same impact position and the same impact velocity at different impact positions. .

Claims

A fretting fatigue test device for steel wire under radial impact conditions, comprising a test bench (16) and an axial steel wire (14), characterized in that: a steel wire tensioner is provided at both ends of the axial steel wire (14). Tensioning device, radial contact device, impact device and spring return device are provided in the middle of the axial steel wire (14);

The steel wire tensioning device includes an electric cylinder (1), a tension sensor (2) and a steel wire clamp (3) connected in sequence, and one end of the tension sensor (2) is connected to the piston thread of the electric cylinder (1) The other end of the rod is connected with the steel wire clamp (3); the end of the axial steel wire (14) is embedded in the steel wire clamp (3), and the steel wire clamp (3) is clamped by screws through the cover plate to ensure the axial The steel wire (14) does not slip when subjected to axial tension;

The radial contact device includes a support rail (6), a steel wire fixing fixture (4) symmetrically arranged on the support rail (6), a fixture support (5) and a track slider (9); a steel wire fixing fixture (4) and the track slider (9) are assembled together through the positioning hole of the fixture support (5); the middle of the steel wire fixing fixture (4) is symmetrically embedded with a contact steel wire (17) in contact with the axial steel wire (14) , The upper and lower ends are clamped and fixed by screws;

The impact device includes an electric cylinder (12) that provides impact force, a tension and compression sensor (11) connected to the piston threaded rod of the electric cylinder (12), and the other end of the tension and compression sensor (11) is connected in a threaded connection Punch (13), the center position of the punch (13) is facing the steel wire contact position; the front side of the impact device is provided with a displacement sensor (15) fixed on the test bench (16), and the measuring position is facing the fixture support (5) Central location;

The spring return device includes a spring fixing block (7) and a spring (8), the spring fixing block (7) is fixed on the support rail (6) with screws, and the spring (8) is fitted to the rail slider (9) and Between the spring fixing blocks (7); adjusting the distance between the guide rail slider (9) and the spring fixing block (7) can control the contact force on both sides of the axial steel wire (14).
The fretting fatigue test device for steel wire under radial impact conditions according to claim 1, characterized in that: the steel wire fixing fixture (4) is a trapezoidal structure block and a square plate connected by screws, The trapezoid-like upper plane is provided with a circular groove for inserting and fixing the steel wire, and the end of the groove is provided with a through hole connecting the fixing plate.
A fretting fatigue test device for steel wire under radial impact conditions according to claim 1, characterized in that: the upper surface of the support rail (6) at the spring fixing block (7) is engraved with equally spaced scales , It is beneficial to control the distance between the rail slider (9) and the spring fixing block (7) on both sides of the support rail (6) during assembly.
A test method for a fretting fatigue device of steel wire under radial impact conditions according to claim 1, characterized in that it comprises the following steps:

a. During the test, the axial steel wire (14) is assembled on the steel wire tensioning device, and the electric cylinder (1) is controlled by the controller to apply a predetermined initial tension to the axial steel wire (14);

b. Fix the contact wire (17) on the wire fixing fixture (4), and adjust the distance between the guide rail slider (9) and the spring fixing block (7);

c. Zero the tension sensor (2), tension and compression sensor (11) and displacement sensor (15);

d. The impact electric cylinder (12) is controlled by the computer to impact the axial steel wire (14); the impact speed of the impact electric cylinder (12) is changed, the output signals of different sensors are collected, and recorded on the computer to obtain different impact speeds Bottom, the radial impact force, radial impact displacement and axial tension received by the axial steel wire (14);

e. Change the position of the impact electric cylinder (12) and adjust the position of the radial contact device so that the center position of the punch of the impact device is facing the contact position of the axial steel wire (14) and the contact steel wire (17);

f. Repeat steps a to e to collect the output signals of different sensors and record them on the computer;

g. Compare, analyze, and calculate all the data obtained, and compare the axial steel wire (14) at the same impact position with different impact speeds and the same impact velocity at different impact positions. The fatigue strength of the axial steel wire (14) and The fatigue life provides the basis.