CN102840968B - 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 blade of aviation engine Stromeyer test, all generally to monitor blade fatigue strength examination stress value by supervision blade tip amplitude, by reading microscope, blade amplitude is read under normal circumstances, Fig. 1 is existing apparatus structural representation, as shown in the figure, existing apparatus comprises fixture, reading microscope, dynamic strain indicator and the 3rd milivoltmeter, but in the time that blade amplitude exceedes 20mm, reading microscope is just difficult to measure.

Summary of the invention

For the deficiencies in the 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 the large-scale fan of aeromotor or gas turbine, compressor blade vibration fatigue test.

A kind of blade of aviation engine wide range vibration amplitude pick-up unit, this device comprises: power supply, fixture, the first bridge road box, the second bridge road box, the first milivoltmeter, the second milivoltmeter and reading microscope, also comprise spiral lifting support, the first current probe and the second current probe, wherein, on described spiral lifting support, be provided with the horizontal fixed mount for fixing the first current probe and the second current probe, the first current probe output terminal connects the input end of the first bridge road box, and the output terminal of the first bridge road box connects the input end of the first milivoltmeter; The output terminal of the second current probe connects the input end of the second bridge road box, and the output terminal of the second bridge road box connects the input end of the second milivoltmeter; Described power supply connects tested blade, and tested blade is fixed on fixture.

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

Step 1, on tested blade, carry out foil gauge position dispose;

Step 2, under blade first-order bending vibration natural frequency, determine the corresponding vibration stress distribution situation of foil gauge on tested blade, and find out 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 corresponding blade vibration amplitude of tired examination stress by fit equation, distance on adjustable screw lifting support between the first current probe and the second current probe, and adjust the height of the spiral lifting bar of spiral lifting support, make tested blade be positioned at the centre position of the first current probe and the 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, the first milivoltmeter and the second milivoltmeter demonstrate magnitude of voltage simultaneously, tested blade is positioned at the centre position of the first current probe and the second current probe, now, detect the amplitude that obtains tested blade and be the corresponding blade vibration amplitude of tired examination stress;

If one of them current probe is touched in tested blade vibration, be that one of them milivoltmeter demonstrates magnitude of voltage, the height of tangent screw elevating lever is until the first milivoltmeter and the second milivoltmeter demonstrate magnitude of voltage simultaneously, tested blade is positioned at the centre position of the first current probe and the second current probe, now, detect the amplitude that obtains tested blade and be the corresponding blade vibration amplitude of tired examination stress.

Advantage of the present invention:

A kind of blade of aviation engine wide range vibration amplitude pick-up unit of the present invention and method, the invention solves wide range vibration amplitude in blade fatigue test and monitor difficult problem, for vibration fatigue test blade tip amplitude monitoring technology provides a kind of brand-new means of testing, expand blade fatigue test vibration stress measuring technology.

Brief description of the drawings

Fig. 1 is existing apparatus structural representation;

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

Wherein, 1-power supply; 2-fixture; 3-the first bridge road box; 4-the second bridge road box; 5-the first milivoltmeter; 6-the second milivoltmeter; 7-spiral lifting support; 8-the first current probe; 9-the 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 schematic diagram.

Embodiment

Below in conjunction with accompanying drawing, the embodiment of the present invention is described further.

As shown in Figure 2, a kind of blade of aviation engine wide range of embodiment of the present invention vibration amplitude pick-up unit, this device comprises: power supply 1, fixture 2, the first bridge road box 3, the second bridge road box 4, the first milivoltmeter 5, the second milivoltmeter 6 and reading microscope 12, also comprise spiral lifting support 7, the first current probe 8 and the second current probe 9, wherein, on described spiral lifting support 7, be provided with the horizontal fixed mount for fixing the first current probe 8 and the second current probe 9, the first current probe 8 output terminals connect the input end of the first bridge road box 3, the output terminal of the first bridge road box 3 connects the input end of the first milivoltmeter 5, the output terminal of the second current probe 9 connects the input end of the second bridge road box 4, and the output terminal of the second bridge road box 4 connects the input end of the second milivoltmeter 6, described power supply 1 connects tested blade 10, and tested blade 10 is fixed on fixture 2.

Adopt blade of aviation engine wide range vibration amplitude pick-up unit to carry out the method for amplitude detecting, as shown in Figure 3, comprise the following steps:

Step 1, on tested blade, carry out foil gauge position dispose;

As shown in Figure 4, in the embodiment of the present invention, strain gauge adhesion is at air inlet edge and the exhaust edge of tested blade and blade basin, the vibration stress value of above-mentioned position is larger, foil gauge is along the axial stickup of tested blade, paste density and determine according to the degree of tested blade vibration STRESS VARIATION, STRESS VARIATION is sharply time, and foil gauge should carry out intensive stickup.

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

Adopt special tool clamping that blade is fixed on electromagnetic vibration generator system, guarantee to connect rigidity enough, find out tested blade first-order bending vibration natural frequency by electromagnetic vibration generator system, in the present embodiment, be 33HZ, under this frequency, little amplitude measurement goes out blade vibration stress distribution situation, determines in first-order bending vibration natural frequency situation the position of maximum vibration stress point on tested blade.If cannot once determine the position of maximum vibration stress point, on the basis of strain gauge adhesion for the first time, again paste foil gauge, redefine the position of maximum vibration stress point, until accurately find the maximum vibration stress point under tested blade first-order bending vibration natural frequency.As shown in Figure 5, the embodiment of the present invention adopts YE6261 data acquisition system (DAS) to gather the corresponding vibration stress value of foil gauge on tested blade, by computing machine, data analysis is found out the position of maximum vibration stress point.

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 corresponding blade vibration amplitude of tired examination stress by fit equation, distance on adjustable screw lifting support between the first current probe and the second current probe, and adjust the height of the spiral lifting bar of spiral lifting support, make tested blade be positioned at the centre position of the first current probe and the second current probe;

Under first-order bending vibration natural frequency, the embodiment of the present invention is by adopting reading microscope to test out the little amplitude amplitude of tested blade, 5～6 groups of different vibration stress lower blade blade tip vibration amplitudes of test maximum stress point, (blade tip place amplitude must not exceed tested blade examination vibration stress amplitude 30%), adopt fit equation to calculate the corresponding blade vibration amplitude of tired examination stress S(unit: mm, double amplitude), concrete formula is as follows:

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

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 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---Natural Frequency of Blade value, unit: Hz;

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

K---foil gauge sensitivity coefficient;

ε---strain value corresponding to blade examination stress

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

E---under 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 present invention adopts SBA-830C dynamic strain indicator metering circuit bridge pressure value (2V left and right), adopts milivoltmeter to measure the magnitude of voltage of foil gauge on tested blade.

Distance on described adjustable screw lifting support between the first current probe and the 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 corresponding 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, the first milivoltmeter and the second milivoltmeter demonstrate magnitude of voltage simultaneously, tested blade is positioned at the centre position of the first current probe and the second current probe, now, detect the amplitude that obtains tested blade and be the corresponding blade vibration amplitude of tired examination stress;

If one of them current probe is touched in tested blade vibration, be that one of them milivoltmeter demonstrates magnitude of voltage, the height of tangent screw elevating lever is until the first milivoltmeter and the second milivoltmeter demonstrate magnitude of voltage (when the first milivoltmeter shows magnitude of voltage simultaneously, spiral lifting bar upwards regulates, when the second milivoltmeter shows magnitude of voltage, spiral lifting bar regulates downwards), tested blade is positioned at the centre position of the first current probe and the second current probe, now, detect the amplitude that obtains tested blade and be the corresponding blade vibration amplitude of tired examination stress.

Now, the amplitude of tested blade is the corresponding blade vibration amplitude of tired examination stress S, makes the sustained vibration on fixture of tested blade, if vibration number exceedes 3 × 10 ⁷still not damaged of inferior tested blade, illustrates that this tested blade is specification product.

Claims (1)

1. a blade of aviation engine wide range vibration amplitude detection method, the method adopts blade of aviation engine wide range vibration amplitude pick-up unit, this device comprises: power supply (1), fixture (2), the first bridge road box (3), the second bridge road box (4), the first milivoltmeter (5), the second milivoltmeter (6) and reading microscope (12), also comprise spiral lifting support (7), the first current probe (8) and the second current probe (9), wherein, on described spiral lifting support (7), be provided with the horizontal fixed mount for fixing the first current probe (8) and the second current probe (9), the first current probe (8) output terminal connects the input end of the first bridge road box (3), the output terminal of the first bridge road box (3) connects the input end of the first milivoltmeter (5), the output terminal of the second current probe (9) connects the input end of the second bridge road box (4), and the output terminal of the second bridge road box (4) connects the input end of the second milivoltmeter (6), described power supply (1) connects tested blade (10), and tested blade (10) is fixed on fixture (2), it is characterized in that: method comprises the following steps:

Step 1, on tested blade, carry out foil gauge position dispose;

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

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

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

If tested blade vibrates two current probes of touching simultaneously, the first milivoltmeter and the second milivoltmeter demonstrate magnitude of voltage simultaneously, tested blade is positioned at the centre position of the first current probe and the second current probe, now, detect the blade tip vibration amplitude that obtains tested blade and be the corresponding blade tip vibration amplitude of tired examination stress;

If one of them current probe is touched in tested blade vibration, be that one of them milivoltmeter demonstrates magnitude of voltage, the height of tangent screw elevating lever is until the first milivoltmeter and the second milivoltmeter demonstrate magnitude of voltage simultaneously, tested blade is positioned at the centre position of the first current probe and the second current probe, now, detect the blade tip vibration amplitude that obtains tested blade and be the corresponding blade tip vibration amplitude of tired examination stress.