CN101539493A - Symmetric signal method for structural damage diagnosis - Google Patents

Symmetric signal method for structural damage diagnosis Download PDF

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Publication number
CN101539493A
CN101539493A CN200910071905A CN200910071905A CN101539493A CN 101539493 A CN101539493 A CN 101539493A CN 200910071905 A CN200910071905 A CN 200910071905A CN 200910071905 A CN200910071905 A CN 200910071905A CN 101539493 A CN101539493 A CN 101539493A
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China
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rod
signal
symmetrical
damage
vibration
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CN200910071905A
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Chinese (zh)
Inventor
郭迅
李国东
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中国地震局工程力学研究所
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Priority to CN200910071905A priority Critical patent/CN101539493A/en
Publication of CN101539493A publication Critical patent/CN101539493A/en

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Abstract

A symmetric signal method for structural damage diagnosis relates to a method for structural damage diagnosis. The invention solves the problems of health criterion loss existing in the existing structural damage diagnosis method, small influence of structural partial damage for structural overall dynamic parameter changing existing in the traditional dynamic parameter method, and low sensibility. The method has the following main steps: testing object is selected; detecting device is arranged according to symmetry principle; member bar excitation and vibration signal acquisition are carried out; information is processed; and structural damage is evaluated. The method in the invention solves the influence of structural health diagnosis loss for damage identification, and has the advantages of high sensibility, strong practicalness, simple analysis and reliable data compared with the traditional dynamic parameter method based on structural whole.

Description

The symmetric signal method that is used for diagnosing structural damage

Technical field

The present invention relates to a kind of method of diagnosing structural damage, belong to bridge, worker health monitoring, detection range with civil engineering structures such as covil construction.

Background technology

The engineering structure Years Of Service decades in addition on century-old; couplings such as environmental attack, material aging fatigue effect and burst disaster will inevitably cause the damage accumulation and the drag decay of structure; thereby cause structure opposing natural disaster; even the ability drop of home effect, can cause the disaster accident under the extreme condition.For the health that guarantees structure is that security, integrality, applicability, permanance need detect and evaluate its health status to existing structure.

Structural health detects and the research of damage recognition technology and focus, the difficult point problem that application is the civil engineering work industry.Present technology generally seeks to solve the method for such problem from aspects such as measuring technology, numerical analysis and signal Processing.Distinct issues mainly show following two aspects:

1, healthy benchmark disappearance

At present most structures of being on active service lack the original power parameter of the structure when making up, and cause kinetic parameter after the test can't define the health status of structure.

2, various damnification recognition methods exist not enough

The recognition methods of the structural entity kinetic parameter that is based on the engineering vibration-testing that operability is stronger in the present damage identification, these class methods distinct issues are that the damage standard of taking all is based on the change amount of damaged structure with respect to intact structure, the damage of the part of structure is very little to the overall dynamics parameter change influence of structure, and sensitivity is not high.Be subject to engineering specifications and measuring method simultaneously, the high-order dynamic information of structural entity is difficult for obtaining.

The numerical analysis technology is based upon on the basis of structural finite element model, owing to be difficult to grasp structural damage mechanism, cause being based upon on the very big degree of model to depend on subjective experience, cause finite element model correction difficulty, the data credibility that calculates depends on the precision and the computing method of model, the bigger error of general existence.

In addition, also have a lot of methods still to rest on theoretical research stage, the operability of engineering practice is not strong, and validity is still to be tested.

Summary of the invention

The present invention exists healthy benchmark disappearance to cause kinetic parameter after the test can't define the health status of structure in order to solve existing diagnosing structural damage method; Traditional kinetic parameter method based on structural entity exists the damage of structure partial very little to the overall dynamics parameter change influence of structure, sensitivity is not high, be subject to engineering specifications and measuring method simultaneously, the high-order dynamic information of structural entity is difficult for the problem of acquisition, and then a kind of symmetric signal method that is used for diagnosing structural damage is provided.

The technical scheme that the present invention solves the problems of the technologies described above employing is:

The symmetric signal method that is used for diagnosing structural damage realizes according to following steps:

Step 1, choose tested object: selected tested object is symmetrical rod member;

Step 2, arrange checkout equipment by symmetry principle: by " symmetry principle " placement sensor, described each sensor is connected on the acquisition instrument supporting with it on each selected symmetrical rod member; The model that described " symmetry principle " is meant each sensor is identical, the installation site of each sensor on symmetrical rod member is identical (relative position that is fixed on the rod member will be determined), and the pick-up direction wants consistent;

Step 3, rod member exciting and vibration signals collecting: on each symmetrical rod member, apply identic vibrational excitation (the rod member exciting mode is identical), by the sensor transmissions vibration information on this bar to acquisition instrument and this vibration information of stored record;

Step 4, information processing: the time-domain signal of the symmetrical rod member free vibration of each that will collect converts amplitude-frequency information to, and obtaining the first natural frequency value of every rod member, this value is used for contrast between each symmetrical rod member as the signal identification amount;

Step 5, structural damage evaluation: will represent the signal identification amount of each rod member health status to compare: each is measured identical rod member to the weighing lever sign and is health status; The sign amount exists significant difference person to be damage rod member (each symmetrical rod member sign is measured different rod members and had damage); Member bar injury causes the natural frequency of rod member to reduce, and finds this difference by frequency values contrast between symmetrical rod member, and there is damage in the little person of frequency.

The present invention is to the contribution of prior art:

Advantages such as the inventive method has solved the influence of structural health benchmark disappearance to damage identification, and more traditional kinetic parameter method based on structural entity has highly sensitive (as shown in figure 12), practicality is strong, analysis is simple, data are reliable.The method is the original power characteristic of dependency structure not, with measurand reference data each other, remove the structure research work of the preceding complexity of test from, only need to carry out general mechanical behavior analysis and can determine the actual measurement scheme, implement convenient and swift the structure of intending assessment.This method is the scientific payoffs that long-term experimental observation of inventor's process and engineering practice sum up.The present invention can apply to civil engineering structure damage and monitoring structural health conditions.

Concrete advantage of the present invention mainly shows the following aspects:

1, solved the problem of structural health benchmark disappearance.Satisfy symmetric condition rod member (or structure) benchmark each other, need not the structure prior imformation and make benchmark.

2, the local damage of accurate recognition structure is indicative strong, highly sensitive.Accompanying drawing 6 is a example method and contrast based on the damnification recognition method of structural entity frequency shift.

3, engineering practicability is strong, and is low to the field condition requirement of intending the survey engineering structure, need not the structure that detects is added, unloads processing especially; The functions of use of interrupt structure (as: bridge is open to traffic, factory building production etc.) not in instrument layout and the testing process realizes higher economic effect.

Description of drawings

Fig. 1 is the FB(flow block) of the inventive method; Fig. 2 is steel truss geometrical construction schematic isometric (a steel truss structural map), and Fig. 3 is the front view (steel truss front elevation view) of steel truss, and Fig. 4 is the vertical view (planimetric map winds up) of Fig. 3, and Fig. 5 is that Fig. 3 is upward view (a lower edge planimetric map); Fig. 6 is the layout synoptic diagram (A represents the rod member of two groups of space symmetries, and every group have two rod members, and B represents that transducer arrangements is at the rod member middle part) of symmetrical rod member and sensor, and Fig. 7 is that the layout synoptic diagram of symmetrical rod member and sensor (has the local meaning of amplifying; Four bar appearance with, sectional dimension is identical, material is identical, the rod member that is connected with main structure body with identical bolt on the border constitutes one group of symmetrical rod member; Transducer arrangements is at the rod member middle part; C is expressed as piezoelectric sensor and gathers rod member y to vibration; D is expressed as the data line that connects Acquisition Instrument), Fig. 8 is rod member exciting and vibration signals collecting process synoptic diagram (sensor 1, rod member 2, rod member end connection 3, rope 4,2kg weight 5), and Fig. 9 is treated to frequency domain signal to obtain rod member natural frequency the poster processing soft result displayed figure (information process with the time of vibration domain information; Last figure is a time of vibration territory signal, and figure below is the auto-power spectrum of vibration signal), Figure 10 is that (the signal identification amount of symmetrical rod member health status is at the spectrogram of the same coordinate system to the spectrogram of weighing lever in contrast; Symmetric signal method principle identification of damage contrasts two rod member not damageds of demonstration intuitively; Intact rod member as benchmark (E26s bar) with it difference the greater damage); Figure 11 is that (the signal identification amount of symmetrical rod member health status is at the spectrogram of the same coordinate system to the spectrogram of weighing lever in contrast; Symmetric signal method principle identification of damage contrasts the rod member that shows numbering E26 and has damage intuitively); Figure 12 is traditional damnification recognition method and symmetric signal method damnification recognition method accuracy of identification comparison diagram.

Embodiment

Embodiment one: shown in Fig. 1~12, the described symmetric signal method that is used for diagnosing structural damage of present embodiment realizes according to following steps:

Step 1, choose tested object: selected tested object is symmetrical rod member;

Step 2, arrange checkout equipment by symmetry principle: by " symmetry principle " placement sensor, described each sensor is connected on the acquisition instrument supporting with it on each selected symmetrical rod member; The model that described " symmetry principle " is meant each sensor is identical, the installation site of each sensor on symmetrical rod member is identical (relative position that is fixed on the rod member will be determined), and the pick-up direction wants consistent;

Step 3, rod member exciting and vibration signals collecting: on each symmetrical rod member, apply identic vibrational excitation (the rod member exciting mode is identical), by the sensor transmissions vibration information on this bar to acquisition instrument and this vibration information of stored record;

Step 4, information processing: the time-domain signal of the symmetrical rod member free vibration of each that will collect converts amplitude-frequency information to, and obtaining the first natural frequency value of every rod member, this value is used for contrast between each symmetrical rod member as the signal identification amount; The vibration information that obtains must convert signal identification amount under identical dimension, the same coordinate system by identical technological means to;

The purpose of this step is the signal identification amount that obtains to be used to judge member bar injury.The mode recognition technology that the common method that adopts is the applying vibration signal obtains the natural frequency of each symmetrical rod member;

Step 5, structural damage evaluation: will represent the signal identification amount of each rod member health status to compare: each is measured identical rod member to the weighing lever sign and is health status; The sign amount exists significant difference person to be damage rod member (each symmetrical rod member sign is measured different rod members and had damage); Member bar injury causes the natural frequency of rod member to reduce, and finds this difference by frequency values contrast between symmetrical rod member, and there is damage in the little person of frequency.

The inventive method need be selected part detecting instrument equipment for use in implementation process, as dial gauge, clock gauge, backguy displacement meter, corner instrument, all types of sensor and supporting Acquisition Instrument, charge amplifier, recording camera etc.Purpose is static(al) or the dynamic Information that obtains to characterize symmetrical rod member duty.Instrumentation should be observed working specification." laying sensor " must select the identical sensor of model for use, and the relative position that is fixed on the every rod member will be determined, gathers the vibration of the identical major axes orientation of rod member.For example symmetrical rod member all adopts the LC0405T piezoelectric sensor, is arranged on the upper section place that the rod member bar is grown the middle part in the accompanying drawing 2, gathers the vibration of rod member y direction.

Embodiment two: shown in Fig. 1~12, present embodiment is meant one group of all identical or close rod members such as the physical dimension of rod member, material properties, boundary condition, duty at symmetrical rod member described in the step 1.Other step is identical with embodiment one.

Embodiment three: shown in Fig. 1~12, the described vibrational excitation of present embodiment in step 3 refers to ripe vibration excitation method; According to the engineering site condition can employing power hammer or weight fall and wait the free vibration method of impact mode or adopt vibrator to carry out the white noise input or sine sweep encourages; Or utilize existing production equipment to make structure produce vibration; Or the pulsation of gathering symmetrical rod member.Other step is identical with embodiment one or two.

Embodiment four: shown in Fig. 1~12, present embodiment converts the time-domain signal (vibration information) of each symmetrical rod member free vibration of obtaining under identical dimension, same coordinate system signal identification amount by identical technological means in step 4.Other step is identical with embodiment three.

Embodiment five: shown in Fig. 1~12, present embodiment is the process that the vibration signal modal parameter extracts in information processing described in the step 4, adopts methods such as FFT conversion, auto-power spectrum, wavelet transformation or S conversion to obtain the contrast that signal signature amounts such as rod member frequency, damping are used for symmetrical rod member.Other step is identical with embodiment one or four.

Embodiment:

Identical in conjunction with eight topological forms, only the part rod member exists the solid space truss (as Fig. 2~5) of damage that this method specific implementation method in engineering is described, this process can be removed and is placed in other similar structures.

(1) chooses symmetrical rod member.Eight truss-frame structures topology forms are identical, number the identical symmetrical each other rod member of rod member on the rod member on truss and other truss.The rod member of space symmetry also is symmetrical rod member in each truss.For example rod member E3, E3S and E4, E4S, E5, E5S and E6, E6S are the rod member of two groups of space symmetries, these eight rod members of while are the symmetric condition of meeting geometric measure-alike (rod member length, sectional dimension are all identical), material identical (Q235 steel), boundary condition similar (being connected with structure web joint same way as bolt) again, and component internal force is on close level, promptly satisfy the close principle of duty, so these eight members constitute one group of symmetry rod member (as shown in Figure 6 and Figure 7).

(2) lay sensor.In this example LC0405T type piezoelectric sensor is fixed on each upper end, cross section (as shown in Figure 6 and Figure 7) to weighing lever middle part by the magnetic mode, in order to the vibration of the vertical direction that writes down every rod member.

(3) rod member exciting and vibration signals collecting.Every excitation method to weighing lever is all identical, (as shown in Figure 8) adopt 2 kilograms of weights to use rope hanging at the rod member middle part, make rod member depart from the equilibrium position slightly, cut off rod member free vibration behind the rope, the rod member vibration information is transferred to Acquisition Instrument and stores this information by sensor and transmission line.

(4) information processing.What collect is the time-domain signal of each rod member free vibration, the auto-power spectrum function that carries by acquisition instrument converts time-domain signal to amplitude-frequency information, obtain the first natural frequency value of every rod member, this value is used for contrast (as shown in Figure 9) between rod member as the signal identification amount.

(5) damage identification.Contrast signal sign amount is found damage.In this example comparing result show in eight truss to be numbered E26 rod member frequency difference remarkable, in fact there is artificial damage really in the rod member in this position, prove symmetric signal method Damage Assessment Method effect remarkable (as shown in Figure 10 and Figure 11).

" symmetric signal method " of the present invention damage principle:

Determine detected object according to symmetry principle, have only the rod member of satisfied " symmetry " condition just to be suitable for this method." symmetric signal method " i.e. be " symmetrical rod member should have symmetric signal ", and symmetrical rod member refers to all identical or close rod members such as the physical dimension, material properties, boundary condition, duty of rod member.Large scale structure for the design of widespread use symmetry principle, especially those versions (as truss-frame structure, grid structure etc.) of mainly forming by long thin rod member or have the structure of growing thin rod member (as stayed structure etc.), symmetrical rod member in the structure is a small probability event in the damage that co-located takes place with degree simultaneously, therefore characterizing static(al), kinetic parameters such as the distortion of symmetrical rod member duty or frequency should equate, otherwise there are damage in distortion the greater or frequency smaller.In brief, symmetrical rod member should have symmetric signal, and there is damage in signal difference person.By this principle, adopt suitable technique technology can obtain the static(al) parameter of symmetrical rod member or kinetic parameter as the signal signature amount, by comparison signal sign amount can the accurate recognition rod member damage.

This method need followed following four implementing process criterions in concrete enforcement: 1) tested object chooses criterion, 2) the collection criterion, 3 of equipment layout and data) data processing criterion and 4) the structural damage interpretational criteria.Described four criterions all satisfy symmetry principle: rod member is measure-alike, the rod member material is identical, the rod member boundary condition is identical; Sensing station, pick-up direction are identical; The rod member exciting mode is identical.In the concrete implementation process, the enforcement of criterion should take into account the actual state of engineering structure.

" symmetric signal method principle " of the present invention refers to for the version of being made up of long thin rod member (as truss-frame structure, grid structure etc.) or has the structure of growing thin rod member (as stayed structure etc.), symmetrical rod member in the structure is a small probability event in the damage that co-located takes place with degree simultaneously, therefore characterizing signals such as the distortion of symmetrical rod member duty or frequency should equate, otherwise there are damage in distortion the greater or frequency smaller.In brief, symmetrical rod member should have symmetric signal, and there is damage in signal difference person.

" tested object choose criterion " refers to select the rod member that the satisfies symmetric condition tested object as diagnosing structural damage according to symmetric signal method principle.The symmetry rod member should have the characteristics of " symmetry ", and " symmetry " refers to has basic characteristics such as physical dimension is identical, material is identical, boundary condition is identical, duty is close between symmetrical rod member.

" the collection criterions of equipment layout and data ", refer to introduce " symmetry " that the signal increment should not change object to be measured by testing in this method enforcement, particularly be exactly during to the tested object operation, vibrational excitation mode, the test apparatus equipment of introduction should be identical.Wherein key link is that the model of sensor is identical, and the relative position that is fixed on the rod member will determine that it is consistent that the pick-up direction is wanted.

" data processing criterion " refers to that the vibration information that obtains converts signal identification amount under identical dimension, the same coordinate system to by identical technological means.

" structural damage interpretational criteria " is symmetric signal method principle.The structural health benchmark is exactly that symmetrical rod member should have identical signal, and there is damage in the remarkable different persons of signal.Herein " signal is significantly different " refer to that the signal relative difference is greater than 2%.When for example being the signal identification amount with the frequency, symmetrical rod member natural frequency value should equate, otherwise may there be damage in the little person of frequency.

Claims (5)

1, a kind of symmetric signal method that is used for diagnosing structural damage, it is characterized in that: described method realizes according to following steps:
Step 1, choose tested object: selected tested object is symmetrical rod member;
Step 2, arrange checkout equipment by symmetry principle: by " symmetry principle " placement sensor, described each sensor is connected on the acquisition instrument supporting with it on each selected symmetrical rod member; The model that described " symmetry principle " is meant each sensor is identical, the installation site of each sensor on symmetrical rod member is identical, and the pick-up direction wants consistent;
Step 3, rod member exciting and vibration signals collecting: on each symmetrical rod member, apply identic vibrational excitation, by the sensor transmissions vibration information on this bar to acquisition instrument and this vibration information of stored record;
Step 4, information processing: the time-domain signal of the symmetrical rod member free vibration of each that will collect converts amplitude-frequency information to, and obtaining the first natural frequency value of every rod member, this value is used for contrast between each symmetrical rod member as the signal identification amount;
Step 5, structural damage evaluation: will represent the signal identification amount of each rod member health status to compare: each is measured identical rod member to the weighing lever sign and is health status; The sign amount exists significant difference person to be the damage rod member; Member bar injury causes the natural frequency of rod member to reduce, and finds this difference by frequency values contrast between symmetrical rod member, and there is damage in the little person of frequency.
2, the symmetric signal method that is used for diagnosing structural damage according to claim 1 is characterized in that: be meant one group of rod member that the physical dimension of rod member, material properties, boundary condition, duty are all identical or close at symmetrical rod member described in the step 1.
3, the symmetric signal method that is used for diagnosing structural damage according to claim 1 and 2 is characterized in that: refer to ripe vibration excitation method in vibrational excitation described in the step 3; According to the engineering site condition can employing power hammer or weight fall and wait the free vibration method of impact mode or adopt vibrator to carry out the white noise input or sine sweep encourages; Or utilize existing production equipment to make structure produce vibration; Or the pulsation of gathering symmetrical rod member.
4, the symmetric signal method that is used for diagnosing structural damage according to claim 3, it is characterized in that: in step 4, convert the time-domain signal of each symmetrical rod member free vibration of obtaining under identical dimension, same coordinate system signal identification amount by identical technological means.
5, according to claim 1 or the 4 described symmetric signal methods that are used for diagnosing structural damage, it is characterized in that: in information processing described in the step 4 is the process that the vibration signal modal parameter extracts, and adopts FFT conversion, auto-power spectrum, wavelet transformation or S transform method acquisition rod member frequency, antihunt signal labelled amount to be used for the contrast of symmetrical rod member.
CN200910071905A 2009-04-28 2009-04-28 Symmetric signal method for structural damage diagnosis CN101539493A (en)

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102392462A (en) * 2011-09-30 2012-03-28 李福清 Method used for monitoring and analysing safe state of foundation ditch adopting mechanical dismantlement
CN102426086A (en) * 2011-11-15 2012-04-25 河海大学 Single-layer framework-structure dynamic stiffness test system
CN103728128A (en) * 2014-01-27 2014-04-16 重庆大学 Damage detection system for semirigid connections of structure members
CN106404914A (en) * 2016-08-26 2017-02-15 四川省建筑科学研究院 Method used for measuring structure damages and safety conditions of Ying county buddha tower
CN107179172A (en) * 2017-06-08 2017-09-19 福州市公路局 Bridge pier based on jump bit washes away condition monitoring system and method
CN107238480A (en) * 2017-06-20 2017-10-10 西北工业大学 Milling process damping scaling method based on operational modal analysis
CN109765038A (en) * 2017-11-10 2019-05-17 财团法人工业技术研究院 The deterioration method for detecting of the structural member of application structure unit
CN110231117A (en) * 2019-06-10 2019-09-13 中设设计集团股份有限公司 A kind of drag-line fundamental frequency feature identification method based on S-transformation
CN110954154A (en) * 2019-11-29 2020-04-03 暨南大学 Bridge damage positioning method based on mobile sensing and filtering integrated system

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102392462A (en) * 2011-09-30 2012-03-28 李福清 Method used for monitoring and analysing safe state of foundation ditch adopting mechanical dismantlement
CN102426086A (en) * 2011-11-15 2012-04-25 河海大学 Single-layer framework-structure dynamic stiffness test system
CN103728128A (en) * 2014-01-27 2014-04-16 重庆大学 Damage detection system for semirigid connections of structure members
CN103728128B (en) * 2014-01-27 2016-07-06 重庆大学 Structural elements varied rigid link damage detection system
CN106404914A (en) * 2016-08-26 2017-02-15 四川省建筑科学研究院 Method used for measuring structure damages and safety conditions of Ying county buddha tower
CN106404914B (en) * 2016-08-26 2019-08-06 四川省建筑科学研究院 The structural damage of a kind of pair of Wooden Pagoda at Yingxian County and the test method of safe condition
CN107179172A (en) * 2017-06-08 2017-09-19 福州市公路局 Bridge pier based on jump bit washes away condition monitoring system and method
CN107238480A (en) * 2017-06-20 2017-10-10 西北工业大学 Milling process damping scaling method based on operational modal analysis
CN107238480B (en) * 2017-06-20 2019-02-12 西北工业大学 Milling process based on operational modal analysis damps scaling method
CN109765038A (en) * 2017-11-10 2019-05-17 财团法人工业技术研究院 The deterioration method for detecting of the structural member of application structure unit
US10801914B2 (en) 2017-11-10 2020-10-13 Industrial Technology Research Institute Method for detecting deterioration defect of structural part using structural unit
CN110231117A (en) * 2019-06-10 2019-09-13 中设设计集团股份有限公司 A kind of drag-line fundamental frequency feature identification method based on S-transformation
CN110954154A (en) * 2019-11-29 2020-04-03 暨南大学 Bridge damage positioning method based on mobile sensing and filtering integrated system

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