CN102840968A - Detection device and detection method for wide-range vibration amplitude of blade of aviation engine - Google Patents

Abstract

The invention provides a detection device and a detection method for wide-range vibration amplitude of a blade of an aviation engine. The detection device comprises a power supply, a fixture, bridge circuit boxes, millivoltmeters, a reading microscope, a spiral lifting support and current probes, wherein two transverse fixing supports for fixing the current probes are arranged on the spiral lifting support. An output end of a first current probe is connected with an input end of a first bridge circuit box. An output end of the first bridge circuit box is connected with an input end of a first millivoltmeter. An output end of a second current probe is connected with an input end of a second bridge circuit box. An output end of the second circuit box is connected with an input end of a second millivoltmeter. The power supply is connected with a detected blade which is fixed on the fixture. The detection device and the detection method solve the problem of difficult monitoring of the wide-range vibration amplitude in a blade fatigue test, provide a completely novel test method for monitoring technology of blade and blade tip vibration amplitude in the vibration fatigue test, and expand test technology of vibration stress in the blade fatigue test.

Description

A kind of blade of aviation engine wide range vibration amplitude pick-up unit and method

Technical field

The invention belongs to aerial motor spare part strength test field, be specifically related to a kind of blade of aviation engine wide range vibration amplitude pick-up unit and method.

Background technology

In the blade of aviation engine Stromeyer test; Generally all be to monitor blade fatigue strength examination stress value, generally the blade amplitude read that Fig. 1 is the existing apparatus structural representation through reading microscope through keeping watch on the blade tip amplitude; As shown in the figure; Existing apparatus comprises anchor clamps, reading microscope, dynamic strain indicator and the 3rd milivoltmeter, but when the blade amplitude surpassed 20mm, reading microscope just was difficult to measure.

Summary of the invention

Deficiency to prior art; The present invention proposes a kind of blade of aviation engine wide range vibration amplitude pick-up unit and method, to solve wide range vibration amplitude monitoring difficult problem in aeromotor or the large-scale fan of gas turbine, the compressor blade vibration fatigue test.

A kind of blade of aviation engine wide range vibration amplitude pick-up unit; This device comprises: power supply, anchor clamps, the first bridge circuit box, the second bridge circuit box, first milivoltmeter, second milivoltmeter and reading microscope; Also comprise spiral lifting support, first current probe and second current probe; Wherein, Described spiral lifting support is provided with the crosswise fixed frame that is used for fixing first current probe and second current probe, and the first current probe output terminal connects the input end of the first bridge circuit box, and the output terminal of the first bridge circuit box connects the input end of first milivoltmeter; The output terminal of second current probe connects the input end of the second bridge circuit box, and the output terminal of the second bridge circuit box connects the input end of second milivoltmeter; Described power supply connects tested blade, and tested vanes fixed is on anchor clamps.

Adopt blade of aviation engine wide range vibration amplitude pick-up unit to carry out the method for amplitude detecting, may further comprise the steps:

Step 1, the position of on tested blade, carrying out foil gauge are disposed;

Step 2, under blade first-order bending vibration natural frequency, confirm the pairing vibration stress distribution situation of foil gauge on the tested blade, and find out the maximum vibration stress point;

Step 3, employing reading microscope read the blade tip vibration amplitude of maximum stress point tested blade under different vibration stresses; And calculate the pairing blade vibration amplitude of tired examination stress with fit equation; Distance on the adjustable screw lifting support between first current probe and second current probe; And the height of the spiral lifting bar of adjustment spiral lifting support, make tested blade be positioned at the centre position of first current probe and second current probe;

Step 4, starter gear make tested blade vibration, adopt current probe to detect the amplitude of tested blade;

If tested blade vibrates two current probes of touching simultaneously; Promptly first milivoltmeter and second milivoltmeter demonstrate magnitude of voltage simultaneously; Then tested blade is positioned at the centre position of first current probe and second current probe; At this moment, detect the amplitude that obtains tested blade and be the pairing blade vibration amplitude of tired examination stress;

If tested one of them current probe of blade vibration touching; Be that one of them milivoltmeter demonstrates magnitude of voltage; Then the height of tangent screw elevating lever demonstrates magnitude of voltage simultaneously until first milivoltmeter and second milivoltmeter; Then tested blade is positioned at the centre position of first current probe and second current probe, at this moment, detects the amplitude that obtains tested blade and is the pairing blade vibration amplitude of tired examination stress.

Advantage of the present invention:

A kind of blade of aviation engine wide range of the present invention vibration amplitude pick-up unit and method; The invention solves the problem of wide range vibration amplitude monitoring difficulty in the blade torture test; For vibration fatigue test blade tip amplitude monitoring technology provides a kind of brand-new means of testing, expanded blade torture test vibration stress measuring technology.

Description of drawings

Fig. 1 is the existing apparatus structural representation;

Wherein, 2-anchor clamps; 14-the 3rd milivoltmeter; The 10-blade; The 11-dynamic strain indicator; The 12-reading microscope; The 13-foil gauge; Fig. 2 is an embodiment of the present invention apparatus structure synoptic diagram;

Wherein, 1-power supply; The 2-anchor clamps; The 3-first bridge circuit box; The 4-second bridge circuit box; 5-first milivoltmeter; 6-second milivoltmeter; 7-spiral lifting support; 8-first current probe; 9-second current probe;

Fig. 3 is an embodiment of the present invention detection method process flow diagram;

Fig. 4 is an embodiment of the present invention foil gauge structural representation;

Fig. 5 is an embodiment of the present invention maximum stress point analysis synoptic diagram.

Embodiment

Below in conjunction with accompanying drawing the embodiment of the invention is further specified.

As shown in Figure 2; A kind of blade of aviation engine wide range of embodiment of the invention vibration amplitude pick-up unit; This device comprises: power supply 1, anchor clamps 2, the first bridge circuit box 3, the second bridge circuit box 4, first milivoltmeter 5, second milivoltmeter 6 and reading microscope 12; Also comprise spiral lifting support 7, first current probe 8 and second current probe 9, wherein, described spiral lifting support 7 is provided with the crosswise fixed frame that is used for fixing first current probe 8 and second current probe 9; First current probe, 8 output terminals connect the input end of the first bridge circuit box 3, and the output terminal of the first bridge circuit box 3 connects the input end of first milivoltmeter 5; The output terminal of second current probe 9 connects the input end of the second bridge circuit box 4, and the output terminal of the second bridge circuit box 4 connects the input end of second milivoltmeter 6; Described power supply 1 connects tested blade 10, and tested blade 10 is fixed on the anchor clamps 2.

Employing blade of aviation engine wide range vibration amplitude pick-up unit carries out the method for amplitude detecting, and is as shown in Figure 3, may further comprise the steps:

Step 1, the position of on tested blade, carrying out foil gauge are disposed;

As shown in Figure 4; In the embodiment of the invention, foil gauge sticks on the air inlet edge and the exhaust edge of tested blade and blade basin, and the vibration stress value of above-mentioned position is bigger; Foil gauge is along the axial stickup of tested blade; Paste density and decide according to the degree of tested blade vibration STRESS VARIATION, when STRESS VARIATION was rapid, foil gauge should carry out intensive stickup.

Step 2, under blade first-order bending vibration natural frequency, confirm the pairing vibration stress distribution situation of foil gauge on the tested blade, and find out the maximum vibration stress point;

Adopt the special tool clamping with vanes fixed on electromagnetic vibration generator system; Guarantee that connection rigidity is enough; Find out tested blade first-order bending vibration natural frequency through electromagnetic vibration generator system; Be 33HZ in the present embodiment, little amplitude measurement goes out blade vibration stress distribution situation under this frequency, determines under the first-order bending vibration natural frequency situation position of maximum vibration stress point on the tested blade.If can't once confirm the position of maximum vibration stress point; On the basis that the first time, foil gauge was pasted; Again paste foil gauge, confirm the position of maximum vibration stress point again, until the maximum vibration stress point that accurately finds under the tested blade first-order bending vibration natural frequency.As shown in Figure 5, the embodiment of the invention adopts the YE6261 data acquisition system (DAS) to gather the pairing vibration stress value of foil gauge on the tested blade, data analysis is found out the position of maximum vibration stress point through computing machine.

Step 3, employing reading microscope read the blade tip vibration amplitude of 5～6 groups of maximum stress points tested blade under different vibration stresses; And calculate the pairing blade vibration amplitude of tired examination stress with fit equation; Distance on the adjustable screw lifting support between first current probe and second current probe; And the height of the spiral lifting bar of adjustment spiral lifting support, make tested blade be positioned at the centre position of first current probe and second current probe;

Under the first-order bending vibration natural frequency; The embodiment of the invention tests out the little amplitude amplitude of tested blade through adopting reading microscope; 5～6 groups of maximum stress point different vibration stress lower blade blade tip vibration amplitudes of test, (blade tip place amplitude must not surpass tested blade examination vibration stress amplitude 30%) adopts fit equation to calculate the pairing blade vibration amplitude of tired examination stress S (unit: mm; Double amplitude), specifically formula is following:

$s=2\mathrm{\η}\×\frac{u}{f}---\left(1\right)$

u=1000U （2）

$U=\frac{\sqrt{2}}{2}\×\frac{k{v}_0}{4}\×\mathrm{\ϵ}---\left(3\right)$

$\mathrm{\ϵ}=\frac{\mathrm{\σ}}{E}---\left(4\right)$

$\mathrm{\η}=\frac{{\left({\mathrm{\Σ}}_{i=1}^n{s}_i{f}_0\right)}^2-n\left[{\mathrm{\Σ}}_{i=1}^n{\left(s_i{f}_0\right)}^2\right]}{\left({\∑}_{i=1}^n{v}_i\right)\left({\∑}_{i=1}^n{s}_i{f}_0\right)-n\left({\∑}_{i=1}^n{v}_i{s}_i{f}_0\right)}---\left(5\right)$

Wherein:

F---be the first-order bending vibration natural frequency, unit: Hz;

v _i---i test point foil gauge connects the reading of milivoltmeter, unit: mv;

s _i---i test point blade tip vibration amplitude (double amplitude), unit: mm;

f ₀---blade natural frequency value, unit: Hz;

v ₀---dynamic strain indicator metering circuit bridge pressure value;

K---foil gauge sensitivity coefficient;

ε---the corresponding strain value of blade examination stress

σ---blade need carry out the stress value (or fatigue limit) of tired examination, unit: Mpa

E---under the room temperature condition, the elastic modulus of blade material, unit: Gpa;

When u---blade tip amplitude reaches examination stress amplitude S value, foil gauge monitor value, unit: mv;

The embodiment of the invention adopts SBA-830C dynamic strain indicator metering circuit bridge pressure value (about 2V), adopts milivoltmeter to measure the magnitude of voltage of foil gauge on the tested blade.

Distance on the described adjustable screw lifting support between first current probe and second current probe; The size of this distance equal blade vibration amplitude S and blade tip thickness δ's and size, wherein said blade vibration amplitude is the pairing blade vibration amplitude of tired examination stress.

Step 4, starter gear make tested blade vibration, adopt current probe to detect the amplitude of tested blade;

If tested blade vibrates two current probes of touching simultaneously; Promptly first milivoltmeter and second milivoltmeter demonstrate magnitude of voltage simultaneously; Then tested blade is positioned at the centre position of first current probe and second current probe; At this moment, detect the amplitude that obtains tested blade and be the pairing blade vibration amplitude of tired examination stress;

If tested one of them current probe of blade vibration touching; Be that one of them milivoltmeter demonstrates magnitude of voltage; Then the height of tangent screw elevating lever demonstrates magnitude of voltage simultaneously until first milivoltmeter and second milivoltmeter (during the first milivoltmeter display voltage value, the spiral lifting bar is to adjusted, during the second milivoltmeter display voltage value; The spiral lifting bar is regulated downwards); Then tested blade is positioned at the centre position of first current probe and second current probe, at this moment, detects the amplitude that obtains tested blade and is the pairing blade vibration amplitude of tired examination stress.

At this moment, the amplitude of tested blade is the pairing blade vibration amplitude of tired examination stress S, makes the sustained vibration on anchor clamps of tested blade, if vibration number surpasses 3 * 10 ⁷Inferior tested blade is not damaged still, and then this tested blade of explanation is specification product.

Claims (2)

1. blade of aviation engine wide range vibration amplitude pick-up unit; This device comprises: power supply (1), anchor clamps (2), the first bridge circuit box (3), the second bridge circuit box (4), first milivoltmeter (5), second milivoltmeter (6) and reading microscope (12); It is characterized in that: also comprise spiral lifting support (7), first current probe (8) and second current probe (9); Wherein, Described spiral lifting support (7) is provided with the crosswise fixed frame that is used for fixing first current probe (8) and second current probe (9); First current probe (8) output terminal connects the input end of the first bridge circuit box (3), and the output terminal of the first bridge circuit box (3) connects the input end of first milivoltmeter (5); The output terminal of second current probe (9) connects the input end of the second bridge circuit box (4), and the output terminal of the second bridge circuit box (4) connects the input end of second milivoltmeter (6); Described power supply (1) connects tested blade (10), and tested blade (10) is fixed on the anchor clamps (2).

2. adopt the described blade of aviation engine wide range of claim 1 vibration amplitude pick-up unit to carry out the method for amplitude detecting, it is characterized in that: may further comprise the steps:

Step 1, the position of on tested blade, carrying out foil gauge are disposed;

Step 2, under blade first-order bending vibration natural frequency, confirm the pairing vibration stress distribution situation of foil gauge on the tested blade, and find out the maximum vibration stress point;

Step 3, employing reading microscope read the blade tip vibration amplitude of maximum stress point tested blade under different vibration stresses; And calculate the pairing blade vibration amplitude of tired examination stress with fit equation; Distance on the adjustable screw lifting support between first current probe and second current probe; And the height of the spiral lifting bar of adjustment spiral lifting support, make tested blade be positioned at the centre position of first current probe and second current probe;

Step 4, starter gear make tested blade vibration, adopt current probe to detect the amplitude of tested blade;

If tested blade vibrates two current probes of touching simultaneously; Promptly first milivoltmeter and second milivoltmeter demonstrate magnitude of voltage simultaneously; Then tested blade is positioned at the centre position of first current probe and second current probe; At this moment, detect the amplitude that obtains tested blade and be the pairing blade vibration amplitude of tired examination stress;

If tested one of them current probe of blade vibration touching; Be that one of them milivoltmeter demonstrates magnitude of voltage; Then the height of tangent screw elevating lever demonstrates magnitude of voltage simultaneously until first milivoltmeter and second milivoltmeter; Then tested blade is positioned at the centre position of first current probe and second current probe, at this moment, detects the amplitude that obtains tested blade and is the pairing blade vibration amplitude of tired examination stress.

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