CN106596100B - A kind of four-step machine tool chief axis elasticity modulus lossless detection method and device - Google Patents
A kind of four-step machine tool chief axis elasticity modulus lossless detection method and device Download PDFInfo
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- CN106596100B CN106596100B CN201710013868.9A CN201710013868A CN106596100B CN 106596100 B CN106596100 B CN 106596100B CN 201710013868 A CN201710013868 A CN 201710013868A CN 106596100 B CN106596100 B CN 106596100B
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- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
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Abstract
The present invention relates to a kind of four-step machine tool chief axis elasticity modulus lossless detection method and devices.The empirical equation that four-step machine tool chief axis pulse excitation detects elasticity modulus is obtained by finite element analysis and Responds Surface Methodology, establish four-step machine tool chief axis elasticity modulus, geometric dimension and corner frequency relationship, and then it is encouraged in four-step machine tool chief axis one end by power hammer, the other end picks up acceleration signal with acceleration transducer, first-order flexure resonant frequency is obtained by Fast Fourier Transform (FFT), with the input of the geometric dimension of four-step machine tool chief axis to be detected empirically formula, elasticity modulus is finally calculated.A shortcomings that energy gram classical pulsed exciting detection elasticity modulus standard method of the invention needs to prepare rectangular section exemplar, is suitable for four-step machine tool chief axis elasticity modulus non-destructive testing under practical working situation；It only needs to hammer exciting vibration into shape by simple power, and only quickly provides four-step machine tool chief axis elastic mould value according to a formula.
Description
Technical field
The invention belongs to mechanical structure technical field of nondestructive testing, and it is lossless to be related to a kind of four-step machine tool chief axis elasticity modulus
Detection method and device.
Background technology
Currently, with the rapid development of national economy, demand of the society to equipment is growing.As equipment key core
Part design manufactures, and numerical simulation becomes a kind of Design and manufacturing process analysis means ripe day by day.However, current generally existing
It imitates without genuine bottleneck problem, there is an urgent need to real structure part mechanics parameters, and elasticity modulus is crucial mechanics parameter.If energy
By lossless detection method, the elasticity modulus of specific structure is obtained, reliable mechanics parameter will be provided for its numerical simulation, had
Very important meaning.
Pulse excitation method is that one kind being known as lossless detection method, by sample (rectangular section standard sample) intrinsic frequency,
Size and quality obtain young modulus of material, modulus of shearing, a kind of method of Poisson's ratio.Pulse excitation method (Impulse
Excitation Technique) refer to that sample one continuous pulse excitation of a certain specific position is given by suitable external force
Signal generates resonance when a certain frequency in accumulation signal is consistent with the intrinsic frequency of sample, and amplitude is maximum at this time, prolongs
When longest, which is received by measurement sensor, then by the analyzing processing of data obtain sample intrinsic frequency,
The intrinsic frequency is different according to the mode of vibration of sample and obtains different types of frequency, such as corner frequency, twisting frequencies, so
Its Young's modulus E, shear modulus G, Poisson when damping ratio etc. are calculated by the empirical equation of standard sample afterwards.Pulse at present
Excitation method has been widely used in research and field of quality control, is suitable for various solid materials, such as metal, alloy, ceramics, glass
Glass, refractory material, graphite etc. are the advanced non-contact one kind for measuring a variety of materials elasticity modulus generally acknowledged in the world at present
Ideal detection method.
However, pulse excitation method is not proper lossless detection method, it is suitable only for rectangular section standard sample, is marked
Quasi- sample itself is with the requirement of specific geometric dimension.For operating condition, severe, ambient vibration noise is greatly and running
Four-step machine tool chief axis, geometry are not standard sample, it is impossible to it is used for quickly detecting with existing pulse excitation method, because
This, there is no report at present.
Invention content
For the technical deficiency more than overcoming, the present invention provides a kind of four-step machine tool chief axis elasticity modulus non-destructive testing side
Method and device.
The present invention provides a kind of four-step machine tool chief axis elasticity modulus lossless detection method, and its step are as follows：
1) four-step machine tool chief axis pulse excitation is obtained by finite element analysis and Responds Surface Methodology and detects elasticity modulus
Empirical equation, establish four-step machine tool chief axis elasticity modulus, geometric dimension and the first rank natural bending frequency relationship；
2) it is being to have suspended four-step machine tool chief axis, wherein L=in midair with elastic metal wire at 0.224L apart from both ends of the surface
l1+l2+l3+l4For main shaft total length, l1, l2, l3, l4Respectively four-step shaft length；
3) it is hammered into shape by power and is encouraged in four-step machine tool chief axis right end, and acceleration letter is picked up in left end acceleration transducer
Number, and the first rank natural bending frequency f is obtained by Fast Fourier Transform (FFT)；
4) by the geometric dimension R of the first rank natural bending frequency f and four-step machine tool chief axis to be detected1, R2, R3, R4, lead to
The relationship in step 1) is crossed, elastic modulus E * is obtained.
Step in step 1) is as follows：Multiple modal frequency calculating is carried out to the four-step machine tool chief axis of simulation, obtains the
First-order flexure intrinsic frequency f, and BBD response surface analysis is carried out to obtaining the first rank natural bending frequency f, it is pre- to obtain elasticity modulus
Measured value E* and geometric dimension R1、R2、R3、R4With the relationship of the first rank natural bending frequency f,
E*=2.15196 × 1011-2.15307×1013R1-2.02443×1013R2-1.70041×1012R3+6.24694
×1012R4+3835003975f-9.04594×1014R1R2-67759500560R1f-4.07318×1014R2R4-
82762415004R2f-9.40012×1013R3R4-15201689270R3f+32685835169R4f+1.1947×1015R1 2+
1.11873×1015R2 2+1.15113×1014R3 2+6.08567×1013R4 2+2536349.853f2,
Wherein R1, R2, R3, R4Respectively four-step axis radius.
The acceleration signal of pickup is passed through into signal conditioner amplification in step 3), digital sample, is filtered, and will
It is input to computer to digital signal, fast Fourier variation is carried out by computer.
A kind of device based on four-step machine tool chief axis elasticity modulus lossless detection method comprising：
Several elastic metal wires, for fixing four-step machine tool chief axis to be measured, and institute fixed position is respectively from both ends
The position of face 0.224L；
Exert a force object, for providing excitation in four-step machine tool chief axis to be measured any one end, makes four-step machine tool chief axis to be measured
Exciting；
Acceleration transducer, along the axial direction setting of four-step machine tool chief axis to be measured, for acquiring four-step machine tool chief axis
Pulse excitation data；
Test system for obtaining pulse excitation data, and carries out the acquisition of elasticity modulus.
The force object is hammered into shape for power.
The test system includes A/D converter amplifier circuits, controller and the display being sequentially connected, and wherein A/D turns
Amplifying circuit is changed to connect with acceleration transducer.
The test system is additionally provided with force snesor, and the force snesor is connect with A/D converter amplifier circuits.
The test system is additionally provided with storing mechanism.
Beneficial effects of the present invention：An energy gram classical pulsed exciting detection elasticity modulus standard method needs to prepare rectangular section
The shortcomings that exemplar, is suitable for four-step machine tool chief axis elasticity modulus non-destructive testing under practical working situation；It only needs by simple
Power hammer exciting vibration into shape, and only according to a formula, quickly provide four-step machine tool chief axis elastic mould value.
Description of the drawings
Fig. 1 is four-step machine tool chief axis simplified model figure.
Fig. 2 is that four-step machine tool chief axis suspends Support Position in midair.
Fig. 3 is the calculated elastic modulus E predicted value of formula (1) and actual value degree of agreement figure.
Fig. 4 is four-step machine tool chief axis elasticity modulus nondestructive detecting instrument block diagram.
Fig. 5 is the test time-domain signal and its frequency spectrum of operating mode 1, and wherein a is test time-domain signal, and b is frequency spectrum.
Fig. 6 is the test time-domain signal and its frequency spectrum of operating mode 2, and wherein a is test time-domain signal, and b is frequency spectrum.
Fig. 7 is five factors, three water-glass of BBD response phase methods.
Fig. 8 is the table of five factors, three 46 test combinations of level of BBD response phase methods.
Fig. 9 is the table of the four-step machine tool chief axis of two kinds of sizes.
Figure 10 is the table of experiment detection elasticity modulus result and error
Specific implementation mode
Embodiments of the present invention is further illustrated below in conjunction with the accompanying drawings：
As shown, the present invention includes obtaining four-step machine tool chief axis pulse by finite element analysis and Responds Surface Methodology
Exciting detect elasticity modulus empirical equation, establish four-step machine tool chief axis elasticity modulus, geometric dimension and corner frequency pass
System, and then encouraged in four-step machine tool chief axis one end by power hammer, the other end picks up acceleration signal with acceleration transducer, leads to
It crosses Fast Fourier Transform (FFT) and obtains first-order flexure resonant frequency, empirically with the geometric dimension of four-step machine tool chief axis to be detected
The input of formula, finally calculates elasticity modulus.Four-step lathe is built using DSP development boards based on detection method
Main shaft elasticity modulus non-destructive testing device.Include the following steps：
1, the empirical equation of four-step machine tool chief axis pulse excitation detection elasticity modulus.
Fig. 1 show four-step machine tool chief axis simplified model figure, is typical multidiameter structure, wherein l1, l2, l3, l4Point
It Wei not four-step shaft length；R1, R2, R3, R4Respectively four-step axis radius.Fig. 2 show the suspention support of four-step machine tool chief axis
Position is 0.224L (L=l apart from both ends of the surface1+l2+l3+l4For main shaft total length), pass through finite element analysis and response surface point
Analysis method obtains the empirical equation of four-step machine tool chief axis pulse excitation detection elasticity modulus, establishes four-step machine tool chief axis springform
Amount, the relationship of geometric dimension and corner frequency.Flow is embodied：
First, one of method in Responds Surface Methodology is utilized --- it is based on the response surface of Box-Behnkendesign (BBD)
Method carries out experimental design.Fig. 7 show five factors, three water-glass of BBD response phase methods.
Five factors, three level of BBD response phase methods need to do 46 experiments, as shown in Figure 8.It is each in BBD response phase methods
Secondary experiment, with finite element analysis software ANSYS, using solid element " Solid 186 ", four-step machine tool chief axis material parameter
For Poisson's ratio μ=0.3, density of material ρ=7860kg/m3, constrained is at 0.224L (as shown in Figure 2), it is assumed that l1=
0.4m, l2=0.3m, l3=0.2m, l4=0.1m carries out modal frequency calculating, obtains the first rank natural bending frequency f, value
As shown in Figure 8.
BBD response phase method analyses are carried out to data shown in Fig. 8, the empirical equation of elastic modulus E can be obtained：
E*=2.15196 × 1011-2.15307×1013R1-2.02443×1013R2-1.70041×1012R3+6.24694
×1012R4+3835003975f-9.04594×1014R1R2-67759500560R1f-4.07318×1014R2R4-
82762415004R2f-9.40012×1013R3R4-15201689270R3f+32685835169R4f+1.1947×1015R1 2+
1.11873×1015R2 2+1.15113×1014R3 2+6.08567×1013R4 2+2536349.853f2 (1)
Formula (1) is the empirical equation of four-step machine tool chief axis pulse excitation detection elasticity modulus, which establishes
Four-step machine tool chief axis Elastic modulus prediction value E*, geometric dimension R1, R2, R3, R4With the relationship of first-order flexure frequency f.The relationship
Formula accuracy is examined under 46 experiment conditions in Fig. 8, true bullet in the elasticity modulus and Fig. 8 that are calculated with formula (1)
Property modulus 170GPa, 190GPa, 210GPa degree of agreement description, as a result as shown in Figure 3, it is seen then that degree of agreement is very good.
2, four-step machine tool chief axis elasticity modulus lossless detection method.
Four-step machine tool chief axis elasticity modulus lossless detection method operating process：
First as shown in Figure 2, it is to have suspended four-step lathe master in midair with elastic metal wire at 0.224L apart from both ends of the surface
Axis；
Then as shown in figure 3, being encouraged in four-step machine tool chief axis right end by power hammer, and in left end acceleration transducer
Pickup acceleration signal obtains digital signal and is input to calculating by processing such as signal conditioner amplification, digital sample, filtering
Machine obtains first-order flexure resonant frequency f by Fast Fourier Transform (FFT)；
The finally geometric dimension R of the four-step machine tool chief axis to be detected by first-order flexure resonant frequency f as shown in figure 31, R2,
R3, R4, empirical equation (1) is substituted into, elastic modulus E * is calculated.
3, the detection device.
Using DSP development boards, four-step machine tool chief axis elasticity modulus non-destructive testing device is built, as shown in Figure 4.It is specific real
Apply flow：
The sensor is acceleration transducer, and along transmission shafts to setting, i.e., is set along close proximity to right end top
It sets, the pulse excitation initial data for acquiring four-step machine tool chief axis.
The test system is additionally provided with force snesor, and the force snesor is connect with A/D converter amplifier circuits.The power senses
Device is extended to solve frequency response function, and then measures material damping.
The controller is also connect with storage device, can will adhere to that data are stored by storage device, can also
It is compared with the numerical value of setting, while can also call and check previous detection data.
Liquid crystal display can also be set thereon, for directly observing data.
Case study on implementation 1：To verify the validity of the method for the present invention, the implementation case provides the four-step lathe of two kinds of sizes
Main shaft, as shown in Figure 9.The test time-domain signal and its frequency spectrum of Fig. 5 and Fig. 6 difference operating mode 1 and operating mode 2.Figure 10 gives experiment
Detect elasticity modulus result and relative error ε=(E*-E)/E × 100%.As seen from Figure 10, for operating mode 1, relative error is only
It is 0.87%, and for operating mode 2, error also only has 1.82%, is a kind of higher lossless detection method of accuracy therefore.Mark
Quasi- pulse excitation method, since its formula is only effective to rectangular section standard sample, and standard sample itself has specific square
The requirement of tee section geometric dimension, therefore, not proper lossless detection method cannot be directed to geometry and non-standard
The four-step machine tool chief axis of sample.And the method for the present invention need not then make rectangular section test specimen, have and be directed to four-step lathe
The quick and accuracy of main shaft.
Embodiment is not construed as limitation of the present invention, any spiritual improvements introduced based on the present invention, all Ying Ben
Within the protection domain of invention.
Claims (7)
1. a kind of four-step machine tool chief axis elasticity modulus lossless detection method, it is characterised in that：Its step are as follows：
1) warp that four-step machine tool chief axis pulse excitation detects elasticity modulus is obtained by finite element analysis and Responds Surface Methodology
Test formula, establish four-step machine tool chief axis elasticity modulus, geometric dimension and the first rank natural bending frequency relationship；
2) it is being to have suspended four-step machine tool chief axis, wherein L=l in midair with elastic metal wire at 0.224L apart from both ends of the surface1+l2+
l3+l4For main shaft total length, l1, l2, l3, l4Respectively four-step shaft length；
3) it is hammered into shape by power and is encouraged in four-step machine tool chief axis right end, and acceleration signal is picked up with acceleration transducer in left end,
And the first rank natural bending frequency f is obtained by Fast Fourier Transform (FFT)；
4) by the geometric dimension R of the first rank natural bending frequency f and four-step machine tool chief axis to be detected1, R2, R3, R4, pass through step
1) relationship in obtains elastic modulus E *,
Step in step 1) is as follows：Multiple modal frequency calculating is carried out to the four-step machine tool chief axis of simulation, obtains the first rank
Natural bending frequency f, and BBD response surface analysis is carried out to obtaining the first rank natural bending frequency f, obtain Elastic modulus prediction value
E* and geometric dimension R1、R2、R3、R4With the relationship of the first rank natural bending frequency f,
E*=2.15196 × 1011-2.15307×1013R1-2.02443×1013R2-1.70041×1012R3+6.24694×
1012R4+3835003975f-9.04594×1014R1R2-67759500560R1f-4.07318×1014R2R4-
82762415004R2f-9.40012×1013R3R4-15201689270R3f+32685835169R4f+1.1947×1015R1 2+
1.11873×1015R2 2+1.15113×1014R3 2+6.08567×1013R4 2+2536349.853f2,
Wherein R1, R2, R3, R4Respectively four-step machine tool chief axis radius.
2. a kind of four-step machine tool chief axis elasticity modulus lossless detection method according to claim 1, which is characterized in that step
It is rapid 3) in by the acceleration signal of pickup by signal conditioner amplification, digital sample, be filtered, and digital signal will be obtained
It is input to computer, fast Fourier variation is carried out by computer.
3. a kind of device based on the four-step machine tool chief axis elasticity modulus lossless detection method described in the claims 1 or 2,
It is characterized in that：It includes：
Several elastic metal wires, for fixing four-step machine tool chief axis to be measured, and institute fixed position is respectively from both ends of the surface
The position of 0.224L；
Exert a force object, for providing excitation in four-step machine tool chief axis to be measured any one end, makes four-step machine tool chief axis exciting to be measured；
Acceleration transducer, along the axial direction setting of four-step machine tool chief axis to be measured, the pulse for acquiring four-step machine tool chief axis
Exciting data；
Test system for obtaining pulse excitation data, and carries out the acquisition of elasticity modulus.
4. device according to claim 3, it is characterised in that：The force object is hammered into shape for power.
5. device according to claim 3, it is characterised in that：The test system includes that the A/D conversions being sequentially connected are put
Big circuit, controller and display, wherein A/D converter amplifier circuits are connect with acceleration transducer.
6. device according to claim 5, it is characterised in that：The test system is additionally provided with force snesor, and the power passes
Sensor is connect with A/D converter amplifier circuits.
7. device according to claim 5, it is characterised in that：The test system is additionally provided with storing mechanism.
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| CN108387643B (en) * | 2018-03-09 | 2020-06-23 | 西南石油大学 | Self-positioning dynamic elastic modulus testing device |
| CN108776430B (en) * | 2018-05-08 | 2021-02-02 | 苏州科技大学 | Position loop gain optimization value taking method for ball screw feeding driving system |
| CN110837247B (en) * | 2018-08-17 | 2023-01-20 | 智能云科信息科技有限公司 | Machine tool performance evaluation method, system, comprehensive system and cloud platform based on machine tool data |
| CN110837248B (en) * | 2018-08-17 | 2023-02-21 | 沈机（上海）智能系统研发设计有限公司 | Machine tool health degree evaluation method, system, comprehensive system and numerical control machine tool |
| CN110987595B (en) * | 2019-12-19 | 2020-11-27 | 北京大学 | Method and device for measuring elastic modulus and internal loss of material in high and low temperature environment |
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Application publication date: 20170426 Assignee: Guowang Technology (Zhejiang) Co.,Ltd. Assignor: Wenzhou University Contract record no.: X2023330000103 Denomination of invention: A nondestructive testing method and device for the elastic modulus of the spindle of a four step machine tool Granted publication date: 20181030 License type: Common License Record date: 20230311 |
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