CN102270249B - Method for identifying characteristic frequency of parts - Google Patents
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- CN102270249B CN102270249B CN2010101943438A CN201010194343A CN102270249B CN 102270249 B CN102270249 B CN 102270249B CN 2010101943438 A CN2010101943438 A CN 2010101943438A CN 201010194343 A CN201010194343 A CN 201010194343A CN 102270249 B CN102270249 B CN 102270249B
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Abstract
The invention provides a method for identifying characteristic frequency of parts. The method comprises the following steps of: establishing a finite element modal model of the parts; applying white noise excitation on an attention area of the finite element modal model; calculating a frequency output of the attention area of the finite element modal model so as to obtain an acceleration response at each frequency; and jugging the characteristic frequency of the parts through an acceleration curve. With the method, the characteristic frequency of each sub-system in complex parts can be clearly identified, which helps engineers to judge more accurately and solve the problem of vibration of the parts; and the method is simpler in application and higher in efficiency.
Description
Technical field
Put it briefly, the present invention relates to a kind of method of identifying characteristic frequency of parts; Specifically, the present invention relates to a kind of method based on finite element analysis identification characteristic frequency of parts, particularly identify the method for complication system characteristic frequency.
Background technology
As everyone knows, mode (vibration shape) is the natural vibration characteristic of physical construction, and each mode all has specific natural frequency, damping ratio and Mode Shape.If understood the characteristic of physical construction each main mode in rank in susceptible frequency range, can foretell the actual vibration response externally or under inner various vibration source effect in this frequency range of this structure.Thereby, thereby model analysis namely obtains to these mode analyses the important method that corresponding modal parameter is the fault diagnosis of structure dynamic design and equipment.Thereby although the actual vibration of machine, buildings, space flight and aviation aircraft, boats and ships, automobile etc. is in different poses and with different expressions, the instant changes, model analysis provides an effective way studying various practical structures kinematic behaviors.
Modal analysis method of the prior art comprises test modal analysis method and computational modal analysis method.The test modal analysis method is by the input of test acquisition system and output signal, thereby then identification obtains modal parameter through parameter; And the computational modal analysis method adopts Finite Element Method to calculate acquisition.Along with the development of robot calculator and Software Industry, there is at present a lot of software can be used for carrying out finite element modal analysis, as OPTISTRUCT, NASTRAN, ANSYS etc.
In the finite element modal analysis process of above-mentioned prior art, particularly when research object was the system of comparatively complexity, the mode of oscillation that calculates was often too in disorder, is difficult to pick out the characteristic frequency of parts of real concern; Perhaps, when by many local modes, being formed the vibration of certain rank, can be very difficult to the numerical value of judging characteristic frequency.For example, Fig. 1 is an example of finite element modal analysis result of calculation in prior art.Specifically, in Fig. 1, schematically shown the computational modal analysis result that the Vehicular instrument panel assembly.Visible, from this figure, being difficult to judge the mode which rank is the vertical and horizontal direction of steering column, this has all caused difficulty to distinguishing and solving of instrument panel structure design problem.
Summary of the invention
In order to address the above problem, the invention provides a kind of method of identifying characteristic frequency of parts, it is characterized in that, described method comprises the steps:
Set up the finite element modal model of described parts;
On the region-of-interest of described finite element modal model, apply white-noise excitation;
Calculate the frequency output on the region-of-interest that obtains described finite element modal model, thereby obtain the acceleration responsive on each frequency; And
By the fluctuation of accelerating curve, judge the characteristic frequency of parts.
Method by identification characteristic frequency of parts as above, owing to adopting Frequency Response Analysis, more can judge intuitively characteristic frequency, from result, reading the frequency response curve of part, and then by each peak value size, carry out the size of judging characteristic frequency, it is very accurate to judge, particularly know mode of oscillation and compare more accurately clearly with rule of thumb debating, and application is simple, is of value to the vibration problem that helps the slip-stick artist to judge more accurately and solve parts.The method also can be applied to the identification of complication system characteristic frequency, to solve the problem that the mode of oscillation that is calculated is too numerous and disorderly, be difficult to judge each subsystem characteristic frequency.
Alternatively, in method as above, described region-of-interest be on described finite element modal model corresponding to material on described part than the zone in territory, hard area.By this method, make excitation better to transmit and be not subject to the impact of parts locally flexibility.
Alternatively, in method as above, described region-of-interest is corresponding to the zone of the mounting bracket of described parts on described finite element modal model.Usually can be higher than other regional rigidity for most system mounting bracket, so, by this method, select stent area can make excitation better to transmit.
Alternatively, in method as above, the amplitude of the structural damping of described finite element modal model is set between 0.01 to 0.02.Preferably, for the system that is formed by metal parts, selecting structure damping 0.01, and the system that forms for plastic part, selecting structure damping 0.02.
Alternatively, in method as above, the amplitude of described structural damping is set as 0.015.The assembly that the present invention relates to mostly is the part metals partly plastic, can the choice structure damping be therefore 0.015.
Alternatively, in method as above, described finite element modal model is the combination of a plurality of model of parts.For complication system, the system that especially a plurality of parts form, can embody advantage of the present invention better.
Alternatively, in method as above, described computation process adopts mode superposition method.Because mode superposition method is higher than direct method counting yield, be 1/3 of direct method computing time.So, by said method, can more effectively calculate.
The accompanying drawing explanation
With reference to accompanying drawing, disclosure of the present invention will be more obvious.Should understand, these accompanying drawings are the purpose for illustrating only, and is not intended to limit scope of the present invention.In figure:
Fig. 1 is an example according to the result of calculation of the finite element modal analysis of prior art;
Fig. 2 schematically shows the process flow diagram according to the method for one embodiment of the present invention identification characteristic frequency of parts;
Fig. 3 schematically shows the finite element model of the complex parts that obtains according to one embodiment of the present invention; Wherein, left figure is whole model analysis computation model, and right figure shows separately the instrument panel model;
Fig. 4 schematically shows computation model point of excitation and output point as a result according to the embodiment of the present invention; And
Fig. 5 schematically shows the result of calculation of embodiments of the present invention.
Embodiment
Explain with reference to the accompanying drawings the specific embodiment of the present invention.Reference numeral identical in accompanying drawing is for the identical technical characterictic of mark.Following explanation is only illustrative, exemplary; although wherein according to the specific embodiment of the present invention, be illustrated; but should understand, in the situation that do not deviate from principle of the present invention, other embodiment of process remodeling or modification also will fall within protection scope of the present invention.
Fig. 1 is an example according to the result of calculation of the finite element modal analysis of prior art.Six width figure in Fig. 1 have listed the front 6 rank Mode Shape situations as certain instrument panel syste of example.Due to the complicacy of model, Mode Shape is to be coupled to form by some local modes and Integral modes.Specifically, in Fig. 1, schematically show the result of calculation of the finite element modal analysis of Vehicular instrument panel assembly, therefrom can find out, the mode result of panel assembly is very complicated, is difficult to differentiate which frequency and is the characteristic frequency of the steering column of paying close attention to.
Fig. 2 schematically shows the process flow diagram according to the method for one embodiment of the present invention identification characteristic frequency of parts.As can be seen from the figure, according to this embodiment of the present invention, the method for identification characteristic frequency of parts comprises the steps: to set up the finite element modal model of described parts; On the region-of-interest of described finite element modal model, apply white-noise excitation; Calculate the frequency output on the region-of-interest that obtains described finite element modal model, thereby obtain the acceleration responsive on each frequency; And the characteristic frequency that judges parts by the fluctuation of accelerating curve.
Fig. 3 schematically shows the finite element modal model of the complex parts that obtains according to the embodiment of the present invention.Specifically, the finite element modal model of Vehicular instrument panel assembly 3 has been shown in Fig. 3, the part of concern is steering column part (referring to Fig. 3) wherein.
Fig. 1 is the FEM modal analysis and modal that Fig. 3 shows model, on this model basis, revises and can also obtain computation model of the present invention.
Below describe the concrete steps of setting up the parts finite element model in one embodiment of the present invention in detail.Concrete step comprises: the part of understanding system to be analyzed forms and matching relationship; Geometric model from each part in download system TEAMCENTER; These geometric models are imported to the finite element pre-processing software for example to be divided network and is accompanied by material and attribute in HYPERMESH; Set up the annexation between each part and set up boundary condition and carry out model analysis; And in HYPERVIEW reading result.
In order to set up well finite element model, at first understand the composition of part in assembly, download the part geometry digital-to-analogue; Import respectively HYPERMESH and carry out grid division, according to parts character, can select to adopt shell unit or solid element carrys out grid division; According to the real material of part, carry out the interpolation of material properties; Then the true matching relationship according to part carries out assembly connection, usually can connect with rigid element; According to the real environment for use of assembly, set up boundary condition, thereby sectional fixture or Car body model need to add in model and obtain boundary condition more accurately in case of necessity.After calculating end, result can be imported in HYPERVIEW, read the accelerating curve with frequency change on each direction of each monitoring point.
Can find out, in above-mentioned steps, by HYPERMESH as the finite element front processor; But the those skilled in the art can understand, and applies other software and equally also can carry out the enforcement of the technology.Should understand, at the finite element model of this importing, can be the combination of a plurality of model of parts.
After the finite element model of having set up parts, can carry out finite element analysis computation to this model.The concrete steps of analytical calculation comprise: set up white noise form and structural damping, for example the frequency of white noise can for from 0Hz to 1000Hz, amplitude can be 1, the frequency of structural damping can for from 0Hz to 1000Hz, amplitude is 0.015; The frequency range of default characteristic frequency in modal analysis result, the frequency range of starting point, step-length and the step number of setpoint frequency output and the required analysis of mode stack accordingly, for example, this band limits can be more than 3 times of output frequency; On near the harder position of the material part of paying close attention to or the part paid close attention to, select several points, and the unit's of applying excitation (white-noise excitation) on the position of these points of corresponding finite element modal model, in conjunction with the white noise form of setting up before is corresponding, set up the frequency response dynamic exciting, thereby set up dynamic load; Adopt mode superposition method to carry out Frequency Response Analysis, call constraint, dynamic load, frequency range, frequency output, damping, and the acceleration result value on part is paid close attention in output.Fig. 4 schematically shows computation model point of excitation and output point as a result according to the embodiment of the present invention, and wherein measuring point illustrates with accompanying drawing figure mark 1, and point of excitation illustrates with Reference numeral 2.
Should understand, so-called white noise, be all consistent accelerating curves of on all frequencies amplitude, and it is converted into actual load in software.In other words, white noise is a kind of field wave that comprises all frequencies, in frequency domain, is an accekeration consistent straight line load all the time.While in software, applying this load, if the material of part is softer, for example plastic part, just need to select hardness certain node higher, its metal support to apply this load.The amplitude of the structural damping of described finite element modal model can be set between 0.01 to 0.02.Preferably, the amplitude of described structural damping can be set as 0.015.So-called constraint can be the constraint that applies according to the actual vehicle situation, for example by displacement, retrains.
By the region-of-interest to the mode model, carry out finite element analysis computation as above, just can obtain frequency output, acceleration calculation result on region-of-interest, then according to these frequency outputs and the mapping of acceleration calculation result, for example make curve map, can obtain intuitively the acceleration responsive result on each frequency; By the fluctuation of this curve, can judge the characteristic frequency of parts.
For above-mentioned calculating, can be by means of NASTRAN as solver at this.And, consider computing time and efficiency, at this, go back the recommend adoption mode superposition method and calculate.The those skilled in the art can understand, and the present invention does not get rid of other suitable computing method; Adopt other suitable computing method also will comprise within the scope of the invention.
Fig. 5 schematically shows the result of calculation of embodiments of the present invention.Wherein, the picture left above is respectively the acceleration responsive curve of the directions X of 5 monitoring points, top right plot is respectively the acceleration responsive curve of the Y-direction of 5 monitoring points, lower-left figure is respectively the acceleration responsive curve of the Z direction of 5 monitoring points, and bottom-right graph is respectively total acceleration responsive curve of 5 monitoring points.In bottom-right graph, curve is the weighted results of other 3 accompanying drawing curves.What in Fig. 5, explain is the acceleration responsive of this part under a certain frequency, and horizontal ordinate is frequency (Hz), and ordinate is acceleration (m/s
2).As can be seen from Figure 5 in the frequency response result of each monitoring point.As shown in FIG., the wave crest point of acceleration responsive is the characteristic frequency point of paying close attention to part.The picture left above is respectively the acceleration responsive curve of the directions X of 5 monitoring points, top right plot is respectively the acceleration responsive curve of the Y-direction of 5 monitoring points, lower-left figure is respectively the acceleration responsive curve of the Z direction of 5 monitoring points, and bottom-right graph is respectively total acceleration responsive curve of 5 monitoring points.In bottom-right graph, curve is the weighted results of other 3 accompanying drawing curves.When input is constant unit white noise, the fluctuation of the curve of output has shown the amplification effect of system for excitation, when visible excitation frequency when input system was consistent with the frequency of curve crest, system will be amplified excitation very many, the result of resonance occurs, this is the characteristic frequency of this system.
In the situation that without departing from the spirit and scope of the present invention; according to the description as front and the teaching of relevant drawings; also can make to the specific embodiment of the present invention other remodeling and modification, but certainly, within these remodeling and modification will drop on protection scope of the present invention.Generally speaking, should be appreciated that protection scope of the present invention is not limited in this disclosed embodiment, remodeling of the present invention, modification and other are equal to embodiment and also will fall in the present invention's scope required for protection.
Claims (7)
1. method of identifying characteristic frequency of parts, described method comprises the steps:
Set up the finite element modal model of described parts;
On the region-of-interest of described finite element modal model, apply white-noise excitation;
Calculate the frequency output on the region-of-interest that obtains described finite element modal model, thereby obtain the acceleration responsive on each frequency; And
By the fluctuation of accelerating curve, judge the characteristic frequency of parts,
It is characterized in that,
The amplitude of the structural damping of described finite element modal model is set between 0.01 to 0.02,
Wherein, the step of obtaining acceleration responsive comprises: set up white noise form and structural damping; The frequency range of default characteristic frequency in modal analysis result, the frequency range of starting point, step-length and the step number of setpoint frequency output and the required analysis of mode stack accordingly; On near the harder position of material described parts or described parts, select several points, and the unit's of applying excitation on the position of these points of corresponding finite element modal model, in conjunction with before the white noise form of foundation is corresponding sets up the frequency response dynamic exciting, thereby set up dynamic load; Adopt mode superposition method to carry out Frequency Response Analysis, call constraint, dynamic load, frequency range, frequency output, damping, and export the acceleration result value on described parts.
2. the method for claim 1, is characterized in that, described region-of-interest be on described finite element modal model corresponding to material on described parts than the zone in territory, hard area.
3. the method for claim 1, is characterized in that, described region-of-interest is corresponding to the zone of the mounting bracket of described parts on described finite element modal model.
4. the method for claim 1, is characterized in that, the amplitude of described structural damping is set as 0.015.
5. method as described as any one in aforementioned claim, is characterized in that, described finite element modal model is the combination of a plurality of model of parts.
6. method as described as any one in claim 1-4, is characterized in that, described calculation procedure adopts mode superposition method.
7. method as claimed in claim 5, is characterized in that, described calculation procedure adopts mode superposition method.
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| CN110779611B (en) * | 2019-05-24 | 2020-10-02 | 南京航空航天大学 | Method and system for calibrating longitudinal vibration frequency of cutter bar of ultrasonic scalpel |
| CN113670549A (en) * | 2021-09-17 | 2021-11-19 | 奇瑞汽车股份有限公司 | Method for detecting vibration transmission characteristics of passenger car seat structure |
| CN114282417A (en) * | 2021-12-27 | 2022-04-05 | 重庆大学 | Continuous elastomer knocking motion pair equivalent model and modeling method thereof |
| CN115096534B (en) * | 2022-06-24 | 2023-03-14 | 大连理工大学 | Compliance surface identification method based on non-reference point partition test |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6211640B1 (en) * | 1999-03-23 | 2001-04-03 | Matsushita Electric Industrial Co., Ltd. | Motor drive control system |
| CN101458259A (en) * | 2007-12-14 | 2009-06-17 | 西北工业大学 | Sensor setting method for supporting failure prediction |
| CN101464205A (en) * | 2008-12-30 | 2009-06-24 | 湖南大学 | Test modal analysis method based on base reduction method |
| CN101487763A (en) * | 2009-02-23 | 2009-07-22 | 西北工业大学 | Method for measuring frequency response function of vibrating structure in large noise environment |
-
2010
- 2010-06-07 CN CN2010101943438A patent/CN102270249B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6211640B1 (en) * | 1999-03-23 | 2001-04-03 | Matsushita Electric Industrial Co., Ltd. | Motor drive control system |
| CN101458259A (en) * | 2007-12-14 | 2009-06-17 | 西北工业大学 | Sensor setting method for supporting failure prediction |
| CN101464205A (en) * | 2008-12-30 | 2009-06-24 | 湖南大学 | Test modal analysis method based on base reduction method |
| CN101487763A (en) * | 2009-02-23 | 2009-07-22 | 西北工业大学 | Method for measuring frequency response function of vibrating structure in large noise environment |
Non-Patent Citations (2)
| Title |
|---|
| 张维锋 等.汽车零部件动态应变场的模态分析法.《汽车工程》.1997,第19卷(第4期), |
| 汽车零部件动态应变场的模态分析法;张维锋 等;《汽车工程》;19971231;第19卷(第4期);摘要，第222页第1段－第224页倒数第1段 * |
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