CN104267104A - Method for detecting shock-absorption and noise-reduction performance of car damping material - Google Patents
Method for detecting shock-absorption and noise-reduction performance of car damping material Download PDFInfo
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- CN104267104A CN104267104A CN201410490780.2A CN201410490780A CN104267104A CN 104267104 A CN104267104 A CN 104267104A CN 201410490780 A CN201410490780 A CN 201410490780A CN 104267104 A CN104267104 A CN 104267104A
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Abstract
The invention discloses a method for detecting shock-absorption and noise-reduction performance of a car damping material. The method comprises detection on two aspects, i.e. the detection of a damping material on the aspect of the feeling of passengers for the vibration noise in the process of simulating the real driving process, and the detection of the damping material on the aspect of reducing the vibration of the overall structure of a car body and the bias of resonant frequency. By adopting a novel method for detecting the shock-absorption and noise-reduction performance of the damping material which is reasonably combined with the car body of a specific car, the shock-absorption performance index of the damping material applied to the car can be simply and intuitively expressed, the complicated modeling work can be omitted, the detection work is relatively simplified, the result is intuitive and dependable, and the application prospect is remarkable.
Description
Technical field
The invention belongs to damping material detection field, be related specifically to a kind of car damping material vibration and noise reducing method for testing performance.
Background technology
Adopt damping material, carrying out vibration and noise reducing process to automobile, has been suitable proven technique.We adopt NVH index usually when studying automobile vibration and noise.NVH is exactly noise (Noise), the abbreviation vibrating the English word of (Vibration) and sound vibration roughness (Harshness).Because this three normally occurs and interwoveness in automobile vibration field, so usually triplicity is studied together simultaneously.Wherein, sound vibration roughness is otherwise known as uneven compliance, is the description to vibration & noise quality, is the subjective sensation of human body to noise and vibration, can not measures by direct objective measurement method.
The source of automobile vibration & noise in the process of moving mainly contains: the vibration noise that (1) engine causes; (2) the flow vibration noise that cause relative to air; (3) vibration noise that causes of tire scrape along the ground; (4) vibration noise that produces of vehicle body kinematic train gears meshing; (5) Uneven road and the vibration etc. caused.
Use damping material can reach the object of vibration and noise reducing.The application of car damping material, dissimilar damping material is selected to process targetedly mainly for certain vibration noise source, object is to reduce vibration & noise amplitude, improves automobile driver and crew comfort level, offsets vehicle body ad hoc structure resonant frequency point, reduces structural wearing and tearing etc.
Damping material is also referred to as visco-elastic damping material, and its principal ingredient is macromolecular material.After damping material is subject to force-extension or compression excitation, due to the viscous-elastic behaviour that material itself has, the response produced will be more delayed than excitation.Delayed effect quantity is turned to drag angle, and its size just can show the damping capacity of this material.Baking bonding damping material on body structure framework, the energy of the body vibrations that can dissipate, thus reach the object of vibration damping.This method, when not changing vehicle body acoustic radiation characteristics, but effectively can control the extent of vibration of vehicle body, thus noise is reduced.
Along with social progress and living standard improve constantly, the requirement of people to comfort level of riding is more and more higher.On the other hand, domestic automobile development of manufacturing is rapid, and it is increasingly competitive, and each automobile manufacturing company strengthens the research to improving automotive quality aspect one after another, and NVH has become the most important technical indicator weighing automotive quality.But because in Automobile Design manufacturing technology, domestic automobile manufacturing enterprise basis is weaker, in Automobile Design in earlier stage, be difficult to all key elements such as the body structure affecting car load NVH quality, chassis vibration damping and power assembly all to consider to put in place, after manufacturing the car sample car that manufactures a finished product, therefore always carried out the rectification of car load NVH again by means such as application damping materials.So damping material is more and more subject to the attention of producer in the application of automobile industry.
But car damping materials industry also exists variety of problems, the performance index of existing evaluation car damping materials'use vibration and noise reducing meet with all puzzlements in actual applications, not too adapt to industry development requirement.Need badly seek a kind of newly can for the damping material vibration and noise reducing performance representation of concrete vehicle and the detection mode supporting with it to adapt to new demand situation, this for car damping material select application and on concrete vehicle body, the process modification of damping material configuration use-pattern all will have important effect.
Existing car damping material property describing mode is with concrete vehicle body damping material collocation method when dynamic excitation is identical at present, and the ratio of damping of damping material is larger, and structural vibration is more weak, noise is lower.In vehicle vibration damping noise reduction engineering, existingly select mode for car damping material, the performance index of Primary Reference are the energy damping coefficients of damping material structure.
In reality test, in engineering, general first damping material baking pastes on the substrate of certain material, then structural test piece entirety is encouraged (power or sound), it is made to produce corresponding response, because the ratio of damping of response characteristic and material has close contact, by processing the data responded and encourage and waveform and analyze, the integral damping coefficient of this structure just can be determined.What tested out by such method is exactly energy damping coefficient based on certain material structure.
The domestic existing damping material collocation method for body structure, the producer that a part of fund is enriched, tachnical storage is more configures damping material targetedly on the basis setting up body in white mode and carry out model analysis.But start late in association area due to domestic, the reasons such as technology is not too perfect, often have that modeling is inaccurate, model and the quite different problem of reality, add body in white mode and baking pastes body mode after damping material, actual when drive a vehicle body mode etc. there is relatively big difference, often there is actual conditions and the inconsistent problem of expectation in the application for damping material.A part of producer still relies on original experience to a great extent to the application of damping material in addition, namely on new model, damping material is used according to original similar vehicle damping material configuration experience, then through simple test, human feeling is taken advantage of to strengthen damping material configuration to the position that vibration & noise is larger in examination.
But in actual applications, due to the complicacy of body structure and environment, when selecting damped products, even if usually occur selection material performance index and structural energy ratio of damping larger, but the situation that the effect of vibration and noise reduction of reality is not fully up to expectations.
Xu Fengchen, Li Honglin, Liu Fu. brief talk the method for testing [J] of automobile damping material ratio of damping. Automobile Technology and Material, 2008, three kinds of method of testings that the 08:63-67. document provides, are all bond material structure measurement ratio of damping, then are applied on integral body, many pilot process, can there is certain error in result.
Summary of the invention
The object of the invention is to overcome the deficiencies in the prior art, a kind of car damping material damping noise reduction method for testing performance is provided, the blind spot that this method avoids the superior and actual use of independent damping property not good, its vibration and noise reducing performance data is intuitively credible, and use relatively simple, to car damping material select and vehicle body damping material collocation method improves and has important effect.
To achieve these goals, the present invention is achieved by the following technical solutions:
A kind of car damping material damping noise reduction method for testing performance, comprises the detection of two aspects:
(1) damping material comprises the following steps this detection of the detection of the impression aspect of vibration noise car in the actual driving conditions of simulation takes out personnel:
A. actuating vehicle under the specified conditions, using the engine of described vehicle as primary oscillation source;
B. at seat bottom, rear, the left and right position of described vehicle, armrest with above bearing circle, the car inner wall bottom surface that contacts of foot arranges acceleration transducer; Along informant's ear height (namely chassis counts 1.1m ~ 1.3m), often row's seat in automobile, a sound pressure sensor is being set, the signal of acceleration transducer and sound pressure sensor by extension line by external A/D converter Real-time Collection current signal, single-chip microcomputer carries out data storage, until stop sampling when specified requirements sections of road is complete, described data are amplitude and frequency;
C. according to (1) a to b step do not paste respectively damping material, former car damping material, experiment damping material measurement contrast experiment, damping material bonding method before its Central Plains car damping material i.e. certain vehicle improvement, specifically comprise the distribution of damping material paste position, use damping material kind and paste thickness, namely experiment damping material adopts and is different from former car damping material, changes the distribution of damping material paste position and pastes thickness;
D. the data gathered transfer frequency domain to by Fourier transform and analyze, Data collecting conversion uses fast fourier transform: suppose that gathered signal is periodic signal, there is the fixing cycle, acquired signal take cycle as substrate, and real signal hypothesis is the combination of the time-domain signal of basic cycle generation endless thus; Suppose that the data length of time-domain signal is N, sequence is x (n), then its fourier coefficient X (k) can be expressed as follows:
wherein, 0≤k≤N-1, makes W
n=e
-2j π/N, therefore above formula becomes
if the length of time-domain signal is the multiple of 2, then above formula can be expressed as odd term and even item and, be expressed as follows:
Formula can be found out thus, and two polynomial expressions on the right of equal sign can decompose equally, and continue according to said process, can accomplish to only require Quadratic Roots Unity 1 always, till-1, is not difficult to set up a recursive resolve scheme by this process.Utilize W
n=e
-2j π/Nsymmetry
and periodically
can find after abbreviation that the order of X (k) and x (n) is the bit reversal of binary number group index, after namely the binary numeral of each array indexing of x (n) being write out, the reversion of its order can be obtained the corresponding array indexing value of X (k), the maximum waveform of Oscillation Amplitude (0.5Hz ~ 50Hz scope) is found from the amplitude-versus-frequency curve of vibration signal, its second-order resonance frequency waveform (20Hz ~ 5000Hz scope) is found in the amplitude-versus-frequency curve of noise signal, by the resonant frequency size of body structure test specimen when it resonates and corresponding bandwidth, determine that the method for the ratio of damping of corresponding test specimen is called half-power bandwidth method in engineering, formula is as follows:
in formula, f
hwhen representing that frequency raises, amplitude compares frequency during the little 3dB of peak value, f
lwhen representing that frequency reduces, amplitude compares frequency during the little 3dB of peak value, Δ f represents half-power bandwidth, f
nrepresent place waveform resonant frequency, sound and the vibration correlation energy ratio of damping η of approximate vehicle body body material structure can be obtained
1,
(2) detection of damping material minimizing that vehicle body one-piece construction is vibrated and resonance point skew aspect
A. by automobile body-in-white and the combination of multiple vibrator, vibrator provides constant vibration source;
B. in the middle part of the vehicle body main member of described automobile, acceleration transducer is set with the resonance position that will offset, for testing this component resonant frequency, and the resonance position that will offset is how many according to concrete vehicle, body accessories, use damping material collocation method different and different; The data variation of acceleration sensor is by signal extension line by external A/D converter Real-time Collection current signal, and single-chip microcomputer carries out data storage, until the standard sample time terminates to stop sampling, described data are amplitude and frequency; Described resonance position, it is different because vehicle structure is different with material, be distributed in the resonance point of the specific position of automobile, normal experiment through this area can determine position, damage is likely caused to automotive material and mechanism in obvious place of resonating, can empathize to the resonance of noise, human body is damaged.
C. a according to (2) does not paste damping material, former car damping material, multiple spot frequency sweep resonance laboratory and the random white noise resonance laboratory successively of testing under damping material condition respectively to b step, the data gathered transfer frequency domain to by Fourier transform and analyze, and the concrete steps of conversion are identical with formula (1) c.The frequency range analyzed is 0 ~ 2000Hz, and Main Analysis target is resonance point, and namely the frequency of one or several point that amplitude is the highest, can obtain the vibration correlation energy ratio of damping η of body in white body material structure
2;
η
1and η
2larger, illustrate that applied damping material vibration and noise reducing performance on certain component of vehicle body is better, stronger for the contribution of body structure Global Macros.The amplitude situation of vibration Main Basis frequency range in 0.5Hz ~ 50Hz of passenger's impression, in this frequency range, amplitude is larger, and the vibration Shaoxing opera that passenger experiences is strong; In like manner, the amplitude situation of noise Main Basis frequency range in 20Hz ~ 5000Hz of passenger's impression, amplitude is larger, and noise is more ear-piercing, and energy damping coefficient η
1and η
2larger, show that the vibration & noise that passenger experiences is more weak, the configuration mode of this damping material in this position is close to optimum;
The present invention former car damping material and experiment damping material are tested, and illustrate that the present invention goes for polytype damping material.
The condition of specifying described in (1) a above, under engine is in idling, acceleration and basic, normal, high at the uniform velocity situation.
The above idling is 700r/min, and described acceleration is 700r/min-2500r/min, described low be at the uniform velocity 1400r/min, be at the uniform velocity 2000r/min in described, described height is at the uniform velocity 2500r/min.
The above vehicle body main member comprises: hood, front mudguard, cowl upper, front panel, covering for roofs, front pillar, roof side rail, top cover side plate, rear deck panel, rear pillar, squab panel, rear fender, center pillar, car door, lower-edge beam, base plate, wing, front longitudinal, front beam, front valance panel, radiator frame, hood front end panel.
The experiment condition of the above multiple spot frequency sweep resonance laboratory is successively: its experiment condition is: experiment place: semi-anechoic room; Experimental subjects: body in white; Experiment condition: vehicle body hangs, adopt vibrator to be placed in body in white construction geometry symmetric points, particular location is that the former tire location of vehicle body places 4 vibrators, and arranging vibrator frequency is that frequency sweep excites successively.
The experiment condition of the above random white noise resonance laboratory is: its experiment condition is: experiment place: semi-anechoic room; Experimental subjects: body in white; Experiment condition: hang, adopt vibrator to be placed in body in white construction geometry symmetric points, particular location is that the former tire location of vehicle body places 4 vibrators, and arranging vibrator frequency is that same frequency white noise excites.
The experiment damping material that the present invention is used is the automobile-used siloxane damping elastomer formula of application number: 201310077414.X, that is: polysiloxane matrix resin 100 weight portion; The oligomeric polyester polyvalent alcohol 10-20 weight portion of number-average molecular weight 100-150, organobentonite 1-5 weight portion, silicone oil 50-60 weight portion, silicon dioxide powder 20-30 weight portion, glass microballoon 20-30 weight portion, antioxidant 2-3 weight portion, oligomeric polyester polyvalent alcohol and bentonite weight ratio are 4-6: 1.The parts by weight sum of silicon dioxide powder and glass microballoon accounts for the 15-20% of composition total weight number.The granularity of silicon dioxide powder is 50-80 micron.Glass microballoon is hollow granularity 50-100 micron.Glass microballoon is hollow granularity 50-100 micron.
Compared with prior art, the invention has the beneficial effects as follows: damping material is directly measured in conjunction with concrete car body entirety, remove damping property measurement and to lose contact with reality the drawback of car body, the damping property obtained more can reflect actual service condition.
The present invention is directed to concrete vehicle, organically combine with vehicle body the new method energy simple, intuitive detecting damping material vibration and noise reducing performance and state damping property index in car damping materials application, walking around Complex Modeling work makes testing relatively simplify, its visual result is credible simultaneously, has suitable application prospect.
Accompanying drawing explanation
Fig. 1 is vehicle body main member structural representation of the present invention;
Fig. 2 is body in white of the present invention and vibrator unitized construction schematic diagram.
Reference numeral: 1-hood, 2-front mudguard, 3-cowl upper, 4-front panel, 5-covering for roofs, 6-front pillar, 7-roof side rail, 8-top cover side plate, 9-rear deck panel, 10-rear pillar, 11-squab panel, 12-rear fender, 13-center pillar, 14-car door, 15-lower-edge beam, 16-base plate, 17-wing, 18-front longitudinal, 19-front beam, 20-front valance panel, 21-radiator frame, 22-hood front end panel, 23-body in white, 24-acceleration sensor, 25-vibrator.
Embodiment
Below in conjunction with embodiment, the present invention is described in further detail, but embodiments of the present invention are not limited to the scope that embodiment represents.
Embodiment 1:
Select certain brand automobile, damp composite material 1 carries out vibration and noise reducing Performance Detection, damp composite material 1 is embodiment 1 product of application number: 201310077414.X, namely in the reactor of 2.5L, add 600 grams of polysiloxane matrix resins, as dimethyl silicone polymer etc., by organobentonite 6 grams, the oligomeric polyester polyvalent alcohol of number-average molecular weight 100 60 grams, silicone oil 300 grams, add in reactor together with antioxidant 12 grams after particle diameter 50 hum silicon dioxide silica flour 120 grams and particle diameter 50 urn glass microballon 120 grams mix, stir, stirring rate is 120raund/min, temperature programme simultaneously, programming rate is 5 DEG C/min, 1h is incubated after being warming up to 90 DEG C, after at 120 DEG C, mediate 30-90min extruding pelletization.The vibration damping of gained elastic body at 25 DEG C and 60 DEG C is 17 and 22, and after sample aging 3 months, at 25 DEG C, vibration damping reduces 4.
(1) damping material comprises the following steps this detection of the detection of the impression aspect of vibration noise car in the actual driving conditions of simulation takes out personnel:
A. actuating vehicle under the specified conditions, using the engine of vehicle as primary oscillation source; The condition of specifying, for engine be in idling (700r/min), accelerate (700r/min->2500r/min) and low (1400r/min), in (2000r/min), high (2500r/min) at the uniform velocity in situation.
B. at seat bottom, rear, the left and right position of vehicle, armrest with above bearing circle, the car inner wall bottom surface that contacts of foot arranges acceleration transducer; Along informant's ear height (i.e. 1.2m), often row's seat in automobile, a sound pressure sensor is being set, the signal of acceleration transducer and sound pressure sensor by extension line by external A/D converter Real-time Collection current signal, single-chip microcomputer carries out data storage, until stop sampling when specified requirements sections of road is complete, data are amplitude and frequency; The section of specified requirements is straight cement flooring, and long 1000 meters, ground is mild.
C. a according to (1) does not paste damping material, former car damping material (damping material thickness 3.5mm respectively to b step, paste position: immediately below motor car engine operator seat, bonding area: 14*45mm, sampled point is for pasting damping material middle), experiment damping material (damping material thickness 5mm, paste position: immediately below motor car engine operator seat, bonding area: 14*45mm, sampled point be paste damping material middle) measurement contrast experiment
The data collected are as shown in table 1:
Table 1
The data gathered transfer frequency domain to by Fourier transform and analyze, Data collecting conversion uses fast fourier transform: suppose that gathered signal is periodic signal, there is the fixing cycle, acquired signal take cycle as substrate, and real signal hypothesis is the combination of the time-domain signal of basic cycle generation endless thus; Suppose that the data length of time-domain signal is N, sequence is x (n), then its fourier coefficient X (k) can be expressed as follows:
wherein, 0≤k≤N-1, makes W
n=e
-2j π/N, therefore above formula becomes
if the length of time-domain signal is the multiple of 2, then above formula can be expressed as odd term and even item and, be expressed as follows:
Formula can be found out thus, and two polynomial expressions on the right of equal sign can decompose equally, and continue according to said process, can accomplish to only require Quadratic Roots Unity 1 always, till-1, is not difficult to set up a recursive resolve scheme by this process; Utilize W
n=e
-2j π/Nsymmetry
and periodically
can find after abbreviation that the order of X (k) and x (n) is the bit reversal of binary number group index, after namely being write out by the binary numeral of each array indexing of x (n), the reversion of its order can be obtained the corresponding array indexing value of X (k); The maximum waveform of Oscillation Amplitude is found, within the scope of 0.5Hz ~ 50Hz from the amplitude-versus-frequency curve of vibration signal; Its second-order resonance frequency waveform is found in the amplitude-versus-frequency curve of noise signal, within the scope of 20Hz ~ 5000Hz, by the resonant frequency size of body structure test specimen when it resonates and corresponding bandwidth, determine that the method for the ratio of damping of corresponding test specimen is called half-power bandwidth method in engineering, the energy damping coefficient η of body material structure can be obtained
1,
in formula, f
hwhen representing that frequency raises, amplitude compares frequency during the little 3dB of peak value; f
lwhen representing that frequency reduces, amplitude compares frequency during the little 3dB of peak value; Δ f represents half-power bandwidth; f
nrepresent place waveform resonant frequency; Vibration and the sound correlation energy ratio of damping η of the body material structure of the actual vehicle body of each condition lower aprons can be obtained thus
1.Result is as shown in table 2:
Table 2
| Calculate data | Do not paste damping material | Former car damping material experiment | Experiment damping material |
| f HSound | \ | 23.0Hz | 19.3Hz |
| f LSound | \ | 35.6Hz | 34.7Hz |
| f nSound | 28.08Hz | 27.9Hz | 28.08Hz |
| f HShake | \ | 135.7Hz | 124.9Hz |
| f LShake | \ | 212.3Hz | 217.4Hz |
| f nShake | 169.3Hz | 169.1Hz | 169.1Hz |
| η 1 | Can not survey, minimum | 0.45 | 0.55 |
Can be known by table 2, this brand automobile, with reality driving simulated condition under, thicken immediately below motor car engine operator seat seat damping material paste thickness can reduce to a certain extent vibration and noise, this is a kind of optimal anchor direction to original damping material collocation method.
(2) damping material comprises the following steps this detection of the detection of the impression aspect of vibration noise car in the actual driving conditions of simulation takes out personnel:
A. by automobile body-in-white and the combination of multiple vibrator, vibrator provides constant vibration source;
B. in the middle part of the vehicle body main member of automobile, (whole critical piece has) and the resonance position (resonance position tried to achieve by test) that will offset arrange acceleration transducer, for testing this component resonant frequency, and the resonance position that will offset is how many according to concrete vehicle, body accessories, use damping material collocation method different and different; The data variation of acceleration sensor is by signal extension line by external A/D converter Real-time Collection current signal, and single-chip microcomputer carries out data storage, until the standard sample time (60s) terminates to stop sampling, described data are amplitude and frequency;
C. a according to (2) does not paste damping material respectively to b step, former car damping material (damping material thickness 5mm, paste position: immediately below car steering position, bonding area: 14*45mm, sampled point is for pasting damping material middle), (damping material thickness 5mm under experiment damping material condition, paste position: immediately below car steering position, original position 5cm to the left, bonding area: 14*45mm, sampled point for paste damping material middle) multiple spot successively frequency sweep resonance laboratory (swept-frequency signal is standard sine signal, vibrator electric current 2.0A, test under voltage 4.1V condition) and random white noise resonance laboratory, the data gathered transfer frequency domain to by Fourier transform and analyze, the concrete steps of conversion are identical with formula (1) d.The frequency range analyzed is 0 ~ 2000Hz, and Main Analysis target is resonance point, i.e. the frequency of one or several point that amplitude is the highest.
The data collected are as shown in table 3:
Table 3
The data gathered transfer frequency domain to by Fourier transform and analyze, Data collecting conversion uses fast fourier transform: suppose that gathered signal is periodic signal, there is the fixing cycle, acquired signal take cycle as substrate, and real signal hypothesis is the combination of the time-domain signal of basic cycle generation endless thus; Suppose that the data length of time-domain signal is N, sequence is x (n), then its fourier coefficient X (k) can be expressed as follows:
wherein, 0≤k≤N-1, makes W
n=e
-2j π/N, therefore above formula becomes
if the length of time-domain signal is the multiple of 2, then above formula can be expressed as odd term and even item and, be expressed as follows:
Formula can be found out thus, and two polynomial expressions on the right of equal sign can decompose equally, and continue according to said process, can accomplish to only require Quadratic Roots Unity 1 always, till-1, is not difficult to set up a recursive resolve scheme by this process; Utilize W
n=e
-2j π/Nsymmetry
and periodically
can find after abbreviation that the order of X (k) and x (n) is the bit reversal of binary number group index, after namely being write out by the binary numeral of each array indexing of x (n), the reversion of its order can be obtained the corresponding array indexing value of X (k); The maximum waveform of Oscillation Amplitude is found, within the scope of 0.5Hz ~ 50Hz from the amplitude-versus-frequency curve of vibration signal; Its second-order resonance frequency waveform is found in the amplitude-versus-frequency curve of noise signal, within the scope of 20Hz ~ 5000Hz, by the resonant frequency size of body structure test specimen when it resonates and corresponding bandwidth, determine that the method for the ratio of damping of corresponding test specimen is called half-power bandwidth method in engineering
in formula, f
hwhen representing that frequency raises, amplitude compares frequency during the little 3dB of peak value; f
lwhen representing that frequency reduces, amplitude compares frequency during the little 3dB of peak value; Δ f represents half-power bandwidth; f
nrepresent place waveform resonant frequency; The vibration correlation energy ratio of damping η of body in white body material structure under each condition can be obtained thus
2.Result is as shown in table 4:
Table 4
| Calculate data | Do not paste damping material | Former car damping material experiment | Experiment damping material |
| f H | \ | 134.2Hz | 116.5Hz |
| f L | \ | 227.3Hz | 214.6Hz |
| f n | 169.1Hz | 169.0Hz | 169.4Hz |
| η 2 | Can not survey | 0.55 | 0.58 |
Known by table 4 interpretation, in body in white structured testing situation, immediately below vehicle body operator seat, damping material paste position offsets certain position left has part to help for minimizing vibration & noise, the vibrational energy ratio of damping improved based on vehicle body.
Test: the inventive method and original method record damping material ratio of damping and contrast
Subjects: damp composite material 1, damp composite material 2
Damp composite material 1 is embodiment 1 product of the above-mentioned application number mentioned: 201310077414.X;
Damp composite material 2 is embodiment 2 product of application number: 201310077414.X, namely in the reactor of 2.5L, add 600 grams of polysiloxane matrix resins, as dimethyl silicone polymer etc., by organobentonite 20 grams, the oligomeric polyester polyvalent alcohol of number-average molecular weight 100 80 grams, silicone oil 330 grams, add in reactor together with antioxidant 15 grams after particle diameter 70 hum silicon dioxide silica flour 150 grams and particle diameter 75 urn glass microballon 150 grams mix, stir, stirring rate is 120raund/min, temperature programme simultaneously, programming rate is 5 DEG C/min, 1h is incubated after being warming up to 90 DEG C, after at 120 DEG C, mediate 30-90min extruding pelletization.The vibration damping of gained elastic body at 25 DEG C and 60 DEG C is 18 and 24, and after sample aging 3 months, at 25 DEG C, vibration damping reduces 5.
Original method: Xu Fengchen, Li Honglin, Liu Fu. brief talk the method for testing [J] of automobile damping material ratio of damping. Automobile Technology and Material, 2008,08:63-67. according to the cantilever method of the document, bond material structure measurement ratio of damping.
Test condition of the present invention: test site: semi-anechoic room, standard white vehicle body, test is carried out at twice, be respectively two kinds of damping material same thickness (0.45mm), be pasted onto the same position of vehicle body (immediately below this brand automobile second row left side seat), the same (80cm of bonding area
2), excitation is similarly standard sine wave vibrational excitation, frequency 80Hz, and sampled point is for pasting damping material middle.
Result is obtained as shown in table 5 through computing:
Table 5
| ? | Composite damping material 1 | Composite damping material 2 |
| Original method records ratio of damping | 0.3 | 0.5 |
| New method records ratio of damping | η 2＝0.35 | η 2＝0.45 |
Apparent by table 5 experimental design, the damping material vibration and noise reducing performance that the inventive method obtains is more intuitively credible.Can know from test findings, the usability of composite damping material 1 immediately below the seat of the vehicle body second row left side is underestimated (new method test result and original method test result compare), and compound substance 2 is over-evaluated in its usability of this position.
Measurement result of the present invention is more intuitively credible, is the angle based on application.The ratio of damping that former method is measured is based on concrete material structure, namely be record on concrete material (such as identical with vehicle body a part material steel plate model), the measuring method newly proposed is then directly test on vehicle body, thus the conclusion drawn to compare former method naturally more intuitively credible.
There is certain deviation in actual applications in the ratio of damping measured by former method, because record ratio of damping in small pieces of material, be applied in again on integral body, many pilot process, certainly exist error, new method omits pilot process from practical application angle, and what obtain is inevitable more intuitively credible in actual use based on vehicle body concrete position ratio of damping.In practical application angle, the inventive method advantageously.
Claims (6)
1. a car damping material vibration and noise reducing method for testing performance, is characterized in that the detection comprising two aspects:
(1) damping material comprises the following steps this detection of the detection of the impression aspect of vibration noise car in the actual driving conditions of simulation takes out personnel:
A. actuating vehicle under the specified conditions, using the engine of described vehicle as primary oscillation source;
B. at seat bottom, rear, the left and right position of described vehicle, armrest with above bearing circle, the car inner wall bottom surface that contacts of foot arranges acceleration transducer; Along informant's ear height, often row's seat in automobile, a sound pressure sensor is being set, the signal of acceleration transducer and sound pressure sensor by extension line by external A/D converter Real-time Collection current signal, single-chip microcomputer carries out data storage, until stop sampling when specified requirements sections of road is complete, described data are amplitude and frequency;
C. according to (1) a to b step do not paste respectively damping material, former car damping material, experiment damping material measurement contrast experiment, damping material bonding method before its Central Plains car damping material i.e. certain vehicle improvement, comprise the distribution of damping material paste position, use damping material kind and paste thickness, namely experiment damping material adopts and is different from former car damping material, changes the distribution of damping material paste position and pastes thickness;
The data gathered transfer frequency domain to by Fourier transform and analyze, Data collecting conversion uses fast fourier transform: suppose that gathered signal is periodic signal, there is the fixing cycle, acquired signal take cycle as substrate, and real signal hypothesis is the combination of the time-domain signal of basic cycle generation endless thus; Suppose that the data length of time-domain signal is N, sequence is x (n), then its fourier coefficient X (k) can be expressed as follows:
wherein, 0≤k≤N-1, makes W
n=e
-2j π/N, therefore above formula becomes
if the length of time-domain signal is the multiple of 2, then above formula can be expressed as odd term and even item and, be expressed as follows:
Formula can be found out thus, and two polynomial expressions on the right of equal sign can decompose equally, and continue according to said process, can accomplish to only require Quadratic Roots Unity 1 always, till-1, is not difficult to set up a recursive resolve scheme by this process; Utilize W
n=e
-2j π/Nsymmetry
and periodically
can find after abbreviation that the order of X (k) and x (n) is the bit reversal of binary number group index, after namely being write out by the binary numeral of each array indexing of x (n), the reversion of its order can be obtained the corresponding array indexing value of X (k); The maximum waveform of Oscillation Amplitude is found, within the scope of 0.5Hz ~ 50Hz from the amplitude-versus-frequency curve of vibration signal; Its second-order resonance frequency waveform is found in the amplitude-versus-frequency curve of noise signal, within the scope of 20Hz ~ 5000Hz, by the resonant frequency size of body structure test specimen when it resonates and corresponding bandwidth, determine that the method for the ratio of damping of corresponding test specimen is called half-power bandwidth method in engineering, formula is as follows:
in formula, f
hwhen representing that frequency raises, amplitude compares frequency during the little 3dB of peak value; f
lwhen representing that frequency reduces, amplitude compares frequency during the little 3dB of peak value; Δ f represents half-power bandwidth; f
nrepresent place waveform resonant frequency; Sound and the vibration correlation energy ratio of damping η of approximate actual vehicle body body material structure can be obtained
1;
(2) detection of damping material reduction that vehicle body one-piece construction is vibrated and resonant frequency shift aspect:
A. by automobile body-in-white and the combination of multiple vibrator, vibrator provides constant vibration source;
B. acceleration transducer is placed in the vehicle body main member horizontal middle of described automobile with the resonance position that will offset, for testing this component resonant frequency, the data variation of acceleration sensor passes through signal extension line by external A/D converter Real-time Collection current signal, single-chip microcomputer carries out data storage, until stop after the standard for manual sampling period, described data are amplitude and frequency;
C. a according to (2) does not paste damping material, former car damping material, multiple spot frequency sweep resonance laboratory and the random white noise resonance laboratory successively of testing under damping material condition respectively to b step, damping material bonding method before its Central Plains car damping material i.e. certain vehicle improvement, comprise the distribution of damping material paste position, use damping material kind and paste thickness, namely experiment damping material adopts and is different from former car damping material, changes the distribution of damping material paste position and pastes thickness; The data gathered transfer frequency domain to by Fourier transform and analyze, and the concrete steps of conversion are identical with formula (1) c; The frequency range analyzed is 0 ~ 2000Hz, and Main Analysis target is resonance point, and namely the frequency of one or several point that amplitude is the highest, can obtain the vibration correlation energy ratio of damping η of body in white body material structure
2;
η
1and η
2larger, illustrate that applied damping material vibration and noise reducing performance on certain component of vehicle body is better, stronger for the contribution of body structure Global Macros.
2. a kind of car damping material vibration and noise reducing method for testing performance according to claim 1, is characterized in that: the condition of specifying in (1) a, under engine is in idling, acceleration and basic, normal, high at the uniform velocity situation.
3. a kind of car damping material vibration and noise reducing method for testing performance according to claim 2, it is characterized in that: described idling is 700r/min, described acceleration is 700r/min-2500r/min, described low be at the uniform velocity 1400r/min, be at the uniform velocity 2000r/min in described, described height is at the uniform velocity 2500r/min.
4. a kind of car damping material vibration and noise reducing method for testing performance according to claim 1, is characterized in that: described vehicle body main member comprises: hood, front mudguard, cowl upper, front panel, covering for roofs, front pillar, roof side rail, top cover side plate, rear deck panel, rear pillar, squab panel, rear fender, center pillar, car door, lower-edge beam, base plate, wing, front longitudinal, front beam, front valance panel, radiator frame and hood front end panel.
5. a kind of car damping material vibration and noise reducing method for testing performance according to claim 1, it is characterized in that: described multiple spot is frequency sweep resonance laboratory successively, its experiment condition is: experiment place: semi-anechoic room; Experimental subjects: body in white; Experiment condition: vehicle body hangs, adopt vibrator to be placed in body in white construction geometry symmetric points, particular location is that the former tire location of vehicle body places 4 vibrators, and arranging vibrator frequency is that frequency sweep excites successively, and 4 vibrator simultaneous shots signals are tested.
6. a kind of car damping material vibration and noise reducing method for testing performance according to claim 1, it is characterized in that: described random white noise resonance laboratory, its experiment condition is: experiment place: semi-anechoic room; Experimental subjects: body in white; Experiment condition: hang, adopt vibrator to be placed in body in white construction geometry symmetric points, particular location is that the former tire location of vehicle body places 4 vibrators, and arranging vibrator frequency is that same frequency white noise excites, and 4 vibrator simultaneous shots signals are tested.
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Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104596718A (en) * | 2015-02-28 | 2015-05-06 | 重庆长安汽车股份有限公司 | Demonstration method for acoustic radiation phenomenon of vehicle stamping part |
| CN104792877A (en) * | 2015-04-03 | 2015-07-22 | 浙江大学 | Method for measuring decoupling performance of underwater decoupling and vibration reducing material |
| CN107607333A (en) * | 2017-09-22 | 2018-01-19 | 太原科技大学 | A kind of vehicle damping material vibration damping method of testing |
| CN108716986A (en) * | 2017-04-04 | 2018-10-30 | 福特环球技术公司 | System and method for the diagnosis of active engine mount |
| CN109827728A (en) * | 2019-03-06 | 2019-05-31 | 北京市劳动保护科学研究所 | Damping structure anti-acoustic capability test bracket, experimental rig and its method |
| CN111781076A (en) * | 2019-10-24 | 2020-10-16 | 东北大学 | Integrated tester and testing method for shock absorption, noise reduction and impact resistance of composite material |
| CN112668208A (en) * | 2021-01-29 | 2021-04-16 | 中国汽车工程研究院股份有限公司 | White car body damping pad arrangement simulation method and simulation device |
| CN112687150A (en) * | 2021-01-27 | 2021-04-20 | 中国人民警察大学 | Fire-fighting forcible entry training module for car |
| CN112697369A (en) * | 2020-12-29 | 2021-04-23 | 贵州联洪合成材料有限公司 | Method for testing and evaluating vibration attenuation effect of damping fin on body-in-white |
| CN113408043A (en) * | 2020-03-17 | 2021-09-17 | 郑州宇通客车股份有限公司 | Matching method and device for whole vehicle tires |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19813065A1 (en) * | 1998-03-25 | 1999-09-30 | Rossendorf Forschzent | Determining stability, or compressibility of disperse material |
| CN101650221A (en) * | 2009-09-14 | 2010-02-17 | 中南大学 | Method for measuring and analyzing noise in train and system thereof |
| CN202814855U (en) * | 2012-09-27 | 2013-03-20 | 贵阳联洪合成材料厂 | Device for determining damping coefficient |
| CN103743476A (en) * | 2013-12-23 | 2014-04-23 | 广西科技大学 | Automobile noise testing method |
| CN103743470A (en) * | 2013-12-23 | 2014-04-23 | 广西科技大学 | Automobile noise spectrum analyzing method |
-
2014
- 2014-09-23 CN CN201410490780.2A patent/CN104267104B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19813065A1 (en) * | 1998-03-25 | 1999-09-30 | Rossendorf Forschzent | Determining stability, or compressibility of disperse material |
| CN101650221A (en) * | 2009-09-14 | 2010-02-17 | 中南大学 | Method for measuring and analyzing noise in train and system thereof |
| CN202814855U (en) * | 2012-09-27 | 2013-03-20 | 贵阳联洪合成材料厂 | Device for determining damping coefficient |
| CN103743476A (en) * | 2013-12-23 | 2014-04-23 | 广西科技大学 | Automobile noise testing method |
| CN103743470A (en) * | 2013-12-23 | 2014-04-23 | 广西科技大学 | Automobile noise spectrum analyzing method |
Non-Patent Citations (2)
| Title |
|---|
| 徐丰辰 等: "浅谈汽车用阻尼材料阻尼系数的测试方法", 《汽车工艺与材料》 * |
| 施亮: "汽车车身NVH减振降噪材料及技术的应用", 《滁州职业技术学院学报》 * |
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104596718A (en) * | 2015-02-28 | 2015-05-06 | 重庆长安汽车股份有限公司 | Demonstration method for acoustic radiation phenomenon of vehicle stamping part |
| CN104792877A (en) * | 2015-04-03 | 2015-07-22 | 浙江大学 | Method for measuring decoupling performance of underwater decoupling and vibration reducing material |
| CN104792877B (en) * | 2015-04-03 | 2017-05-17 | 浙江大学 | Method for measuring decoupling performance of underwater decoupling and vibration reducing material |
| CN108716986B (en) * | 2017-04-04 | 2022-04-19 | 福特环球技术公司 | System and method for active engine mount diagnostics |
| CN108716986A (en) * | 2017-04-04 | 2018-10-30 | 福特环球技术公司 | System and method for the diagnosis of active engine mount |
| CN107607333A (en) * | 2017-09-22 | 2018-01-19 | 太原科技大学 | A kind of vehicle damping material vibration damping method of testing |
| CN107607333B (en) * | 2017-09-22 | 2019-11-08 | 太原科技大学 | A kind of vehicle damping material vibration damping test method |
| CN109827728A (en) * | 2019-03-06 | 2019-05-31 | 北京市劳动保护科学研究所 | Damping structure anti-acoustic capability test bracket, experimental rig and its method |
| CN109827728B (en) * | 2019-03-06 | 2020-10-09 | 北京市劳动保护科学研究所 | Damping structure noise reduction performance test support, test device and method |
| CN111781076A (en) * | 2019-10-24 | 2020-10-16 | 东北大学 | Integrated tester and testing method for shock absorption, noise reduction and impact resistance of composite material |
| CN113408043A (en) * | 2020-03-17 | 2021-09-17 | 郑州宇通客车股份有限公司 | Matching method and device for whole vehicle tires |
| CN113408043B (en) * | 2020-03-17 | 2024-04-05 | 宇通客车股份有限公司 | Whole vehicle tire matching method and device |
| CN112697369A (en) * | 2020-12-29 | 2021-04-23 | 贵州联洪合成材料有限公司 | Method for testing and evaluating vibration attenuation effect of damping fin on body-in-white |
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