CN103911958B - The damage reason location system of suspension bridge and arch bridge suspender periodic detection and method thereof - Google Patents

Abstract

The invention discloses the damage reason location system of a kind of suspension bridge and arch bridge suspender periodic detection and two kinds of damage positioning methods of this system use, belong to engineering structure damage detection technique field. It is characterized in that, this system comprises stimulating module, data acquisition module, data analysis module, four parts of decision-making module; Wherein key technology is two kinds of damage positioning methods of the suspension rod invented. The present invention is applicable to damage reason location and the safety evaluation of suspension bridge and arch bridge suspender, have with low cost, easy to operate, save manpower, noise robustness strong, need not the advantage such as numerical model of structure.

Description

The damage reason location system of suspension bridge and arch bridge suspender periodic detection and method thereof

Technical field

The invention belongs to the structural damage detection technical field based on vibration, relate to the damage reason location of suspension rod in the structure such as suspension bridge and arch bridge, specifically invented damage reason location system and the method thereof of suspension rod periodic detection.

Background technology

Structural damage detection technology based on vibration adopts certain algorithm to be analyzed to discovery, location, even amount damage by the vibration response signal that the sensor installed structurally is recorded, and has quick detection, saves the advantages such as manpower; Receive extensive concern and have made great progress,

Suspension bridge and arch bridge are two main bridge types of Longspan Bridge in civil engineering structure, and this two class formation is all invested huge, and is the key components in whole road network system, may often be such that the unique current approach in little scope; Thus it is guaranteed that it is on active service safely extremely important. Research shows, suspension rod is often served in severe natural environment and heavily stressed lower work, is that in suspension bridge and arch bridge structure stress system, most critical is also the part being easiest to occur damage. Identify the earlier damage general safety to Longspan Bridge of suspension rod, on-call maintenance and saving maintenance cost etc. in time significant. In general, the damage of suspension rod is progressively to accumulate and formed for a long time, so periodic detection can meet the needs of safety of structure; Can on-call maintenance or the replacing suspension rod generation to avert a calamity after finding damage.

The damage detection system of the development structure middle hanger such as suspension bridge and arch bridge is significant; But, suspension bridge and in these long-span bridges of arch bridge based on the damage check of the suspension rod of vibration information also face big by noise jamming, structure numerical model degree of accuracy is had the challenges such as bigger dependence; The two challenge directly affects the reliability of suspension rod damage reason location result.

Summary of the invention

In order to grasp service state and the damage profile of large-scale suspension bridge and arch bridge structure middle hanger in time, damage reason location system and the method (such as Fig. 1 and Fig. 2) thereof of suspension bridge and arch bridge suspender periodic detection are invented, it is characterised in that this system is by stimulating module, form according to acquisition module, data analysis module, decision-making module;

Wherein stimulating module is be sequentially arranged on the measuring point of every suspension rod by a Wireless Acceleration Sensor, and firmly hammer is encouraged the measuring point of every suspension rod one by one and recorded the amplitude of pulse excitation by the force transducer in power hammer tip portion;

Data acquisition module gathers the pumping signal of force sensor and respectively from the acceleration signal that the Wireless Acceleration Sensor of suspension rod measuring point sends, and every suspension rod is gathered successively, and stores in a computer;

Data analysis module adopts two kinds of damage positioning methods of the suspension rod proposed be calculated and provide damage reason location result for pumping signal and the acceleration signal of all suspension rods collected;

Decision-making module displays whether damage suspension rod and the numbering of damage suspension rod, if not damaged suspension rod, then illustrates that all suspension rods are all safe; If there being damage suspension rod, re-using the local detection methods such as the physics Non-Destructive Testing suspension rod to damage and detecting, then make maintenance according to the seriousness of suspension rod damage or change the decision-making of suspension rod.

For the relation of sequencing between four modules: first encourage suspension rod; Then pumping signal and acceleration vibration response signal are gathered; Again the signal that all these collect is sent in data analysis module and is calculated by the two kinds of damage positioning method modules proposed; Result of calculation can display whether damage suspension rod and the numbering of damage suspension rod; Finally in decision-making module, it is again based on the physical detection tool and method suspension rod having damage to having found carry out degree of injury assessment and take final decision. Present invention incorporates wholeness method and suspension rod is detected by local approach.

The first damage positioning method of suspension bridge and arch bridge suspender periodic detection comprises the steps:

Step one, measuring point and point of excitation are arranged: arrange a fixing measuring point and a fixing point of excitation on every suspension rod to be detected;

Step 2, acquisition acceleration responsive: the point of excitation at every suspension rod is firmly hammered into shape to encourage this suspension rod with suspension rod rope face vertical direction, and excitation amplitude recorded by the force transducer in power hammer tip portion simultaneously, and is transferred in the data acquisition module of computer; Data acquisition module is based respectively on the acceleration on the structure all measuring points of acquisition of the structure before damage and unknown state with excitation orientation equidirectional; Excitation amplitude is normalized by the acceleration signal obtained under different pulse excitation amplitudes, obtains the acceleration responsive under unit excitation amplitude (1N);

Step 3, calculate the correction logarithm acceleration energy of each measuring point acceleration responsive: acceleration time series (the signal a of measuring point on suspension rod k^k) each scatterplot beThen acceleration signal a^kCorrection logarithm acceleration energy MLAE be

$MLAE\left(a^k\right)=log\underset{i=1}{\overset{N-1}{\Σ}}{\left(a_i^k{a}_{i+1}^k\right)}^2---\left(1\right)$

Wherein log is common logarithm, and N is that signal is counted; Before and after damage, the acceleration responsive data length for calculating should be identical, selects complete pulse excitation acceleration responsive to be calculated; After obtaining the correction logarithm acceleration energy of each measuring point, connect these values and just can obtain revising logarithm acceleration energy waveform;

Logarithm acceleration energy waveform difference is revised in step 4, calculating: the correction logarithm acceleration energy difference D of measuring point place signal on suspension rod k before and after damage^kDefine as follows,

${\left(D^k\right)}_{rs}={\left({\mathrm{MLAE}}_{before}^k\right)}_r-{\left({\mathrm{MLAE}}_{after}^k\right)}_s---\left(2\right)$

Wherein (D^k)_rsThe D that the s response signal after being individual for the r before damaging and damaging is calculated^k,It is the correction logarithm accelerated energy value of r the response signal at measuring point place on the front suspension rod k of damage,It it is the correction logarithm accelerated energy value of s the response signal at measuring point place on damage rear suspension bar k;

Step 5, the correction logarithm acceleration energy difference D that all measuring point places are gone out based on a pair RESPONSE CALCULATION before damage and after damage^kBeing normalized, in identifying, maximum correction logarithm acceleration energy difference becomes 1 so every time; Correction logarithm acceleration energy difference after normalization is

${\left(D^k\right)}_{rs}^{*}={\left(D^k\right)}_{rs}/\underset{k}{max}\[{\left(D^k\right)}_{rs}\]---\left(3\right)$

To repeatedly encouraging the many groups acceleration of vibration collected to carry out step one to after the repeatedly calculating of step 5 in step 6, data analysis module, definition damage criterion is average normalized correction logarithm acceleration energy waveform difference; The damage criterion value such as following formula of measuring point on suspension rod k

${\left(DI\right)}_k={\mathrm{\μ}}_k=\frac{1}{RS}\underset{r=1}{\overset{R}{\Σ}}\underset{s=1}{\overset{S}{\Σ}}{\left(D^k\right)}_{rs}^{*}---\left(4\right)$

Rule of thumb, RS >=10; The value of RS is the bigger the better, in actually used generally desirable 20;

Step 7, decision-making module: the average normalized correction logarithm acceleration energy difference μ at suspension rod measuring point place_kBe more than or equal to δ, this suspension rod is determined as damage suspension rod, namely

Damage suspension rod={ (DI)_k≥δ}(5)

Wherein δ is the threshold value introduced in order to avoid the appearance of false positive result; δ determines based on the damage reason location result of vibratory response data under lossless operating mode, and δ is a mean μ poorer than the normalization correction logarithm acceleration energy of lossless operating mode_kBigger value;

If there being damage suspension rod, using the local detection methods such as physics Non-Destructive Testing that the suspension rod of damage is detected, then making maintenance according to the seriousness of suspension rod damage or changing the decision-making of suspension rod.

The second damage positioning method of suspension bridge and arch bridge suspender periodic detection comprises the steps:

Step one is identical with the first suspension bridge and arch bridge suspender periodic sensing approach to step 5; Thus obtain all measuring point place normalization damage characteristic differences of function

Step 6, determine that whether normalization damage characteristic function difference is be more than or equal to threshold value δ,

${\mathrm{\Γ}}_{rs}^k=H\left\{{\left(D_{\mathrm{\Δ}}^k\right)}_{rs}^{*}\right\}---\left(6\right)$

Wherein H () is Heaviside jump function, if the value that normalization damage characteristic function difference is be more than or equal to threshold value δ, H () is 1, otherwise its value is 0; δ herein is identical with the threshold value δ in formula (5).

Step 7, data analysis module observe each unit appearance situation in multi damage positioning result based on identifying of RS group data by being used for, in definition repeatedly identification, each unit accounts for the damage probability that percentage ratio is unit of total degree be more than or equal to the number of times of threshold value, and the damage probability of measuring point on suspension rod k is defined as the damage criterion (DI) of suspension rod k_k, its formula is as follows:

${\left(DI\right)}_k=\frac{1}{RS}\underset{r=1}{\overset{R}{\Σ}}\underset{s=1}{\overset{S}{\Σ}}{\mathrm{\Γ}}_{rs}^k---\left(7\right)$

Step 8, decision-making module: the damage probability unit be more than or equal to probability threshold value ρ is defined as damage unit, namely

Damage suspension rod={ (DI)_k≥ρ}(8)

Wherein ρ is probability threshold value, and the damage probability result based on lossless data is determined. If the damage probability of each unit is both less than ρ in the repeatedly recognition result of certain operating mode, then this operating mode is lossless operating mode.

If there being damage suspension rod, using the local detection methods such as physics Non-Destructive Testing that the suspension rod of damage is detected, then making maintenance according to the seriousness of suspension rod damage or changing the decision-making of suspension rod.

The beneficial effects of the present invention is, it is not necessary to the FEM (finite element) model of suspension bridge or arch bridge is thus having saved the modeling of large amount of complex and the workload of Modifying model; And easy and simple to handle, people, power hammer, Wireless Acceleration Sensor (or an acceleration transducer and a set of collecting device) and computer just can complete the damage reason location of large-span suspension bridge or arch bridge suspender. The key technology of the present invention is two kinds of damage positioning methods (such as Fig. 3) of the suspension rod proposed, both approaches adopt pulse excitation single suspension rod is encouraged, increase vibration response signal by improving excitation amplitude and then increase the method for signal to noise ratio and can reduce the noise level of signal, it is proposed that method greatly reduce the noise impact on damage reason location result accuracy.This invention is applicable to the periodic detection of the structure middle hanger such as suspension bridge and arch bridge, has saving manpower, with low cost, simple operation and other advantages, has certain using value in Practical Project.

Accompanying drawing explanation

Fig. 1 present system schematic diagram

Fig. 2 schematic flow sheet of the present invention

Two kinds of damage positioning method modules of Fig. 3 suspension rod

Fig. 4 bridge spanning the sea FEM (finite element) model

Fig. 5 suspension bridge minor structure object of study sketch and point layout

The average normalized damage characteristic difference of function result of the lossless operating mode of Fig. 6

The characteristic function difference probability results of the lossless operating mode of Fig. 7

Fig. 8 is based on the positioning result of the damage regime 1 of first method

Fig. 9 is based on the positioning result of the damage regime 2 of first method

Figure 10 is based on the positioning result of the damage regime 3 of first method

Figure 11 is based on the positioning result of the damage regime 1 of second method

Figure 12 is based on the positioning result of the damage regime 2 of second method

Figure 13 is based on the positioning result of the damage regime 3 of second method

Abscissa in Fig. 6～13 is suspension rod numbering, wherein Fig. 6, vertical coordinate is normalization correction logarithm acceleration energy waveform difference average in 8～10, if the normalization correction logarithm acceleration energy waveform difference average of certain suspension rod is more than threshold value 0.25, then it is damage suspension rod; Fig. 7, vertical coordinate is damage probability in 11～13, if the damage probability of certain suspension rod is more than threshold value 60%, then it is damage suspension rod

Detailed description of the invention

Detecting for the suspension rod of suspension bridge, the numerical model choosing bridge spanning the sea carries out the research of suspension rod damage reason location as object of study, below in conjunction with accompanying drawing, technical scheme is described in detail:

1) FEM (finite element) model

Full-bridge both sides end bay is respectively arranged with 30 suspension rods (each 15 of each end bay upstream and downstream), and main span has 78 suspension rods (upstream and downstream is respectively arranged with 39). Setting up its FEM (finite element) model as shown in Figure 4 based on ANSYS software, wherein king-tower and double-deck truss-type bridges plane system adopt beam4 three-dimensional beam element to set up, and main push-towing rope and suspension rod adopt link10 unit.

2) point layout and acquisition vibratory response

Such as Fig. 5, the right half part (i.e. Blocked portion in Fig. 5) selecting bridge spanning the sea main span is object of study, and this parton structure has 20 suspension rods. Increasing by two nodes on every suspension rod in suspension bridge FEM (finite element) model, wherein point of excitation is from bridge floor distance 1.5m, and measuring point is from bridge floor 1m. In FEM (finite element) model, the point of excitation of every suspension rod sequentially inputs laterally (with suspension rod face vertical direction) excitation; The FEM (finite element) model being based respectively on lossless structure and damaged structure obtains the lateral acceleration of lower 20 measuring points of corresponding state. Sample frequency is 50Hz, needs to obtain the complete vibratory response comprising whole attenuation process under pulse excitation in calculating, and taking the sampling time according to analog result is more than 7 seconds. In Practical Project detection, it is only necessary to an acceleration transducer, it is installed on a suspension rod and tests, move on other suspension rod afterwards successively.

3) damage regime: the damage suspension rod preset in this Suspension bridge structure is positioned based on several damage regime in table 1.

Table 1 suspension rod damage regime

4) threshold value is determined

Determine threshold value δ: be primarily based on the result of lossless operating mode to determine that δ, δ are normalization damage characteristic difference of function mean μ than lossless operating mode_k(acceleration signal based on lossless structure is obtained according to the formula (4) of damage positioning method 1) big value is to avoid the appearance of wrong report unit. Fig. 6 illustrates the μ of lossless operating mode under 5% noise level_kAs a result, therefrom determine that threshold value δ is 0.25.

Determining that probability threshold value ρ: ρ is determined based on the damage probability result of lossless operating mode, under 5% noise level, the damage probability result of lossless operating mode is as shown in Figure 7; Wherein ρ should be greater than all values in the damage probability result of lossless operating mode and avoids the appearance of wrong report unit, and if probability threshold value ρ is too greatly it would appear that fail to report unit; Finally determine that probability threshold value ρ is 60%.

5) the damage reason location result of single injury operating mode

Use the two kinds of damage positioning methods proposed that damage regime 1～2 is detected: according to abovementioned steps (Fig. 3), when noise level 5%, based on the result of single injury operating mode of first method respectively as shown in Fig. 8～9; Based on the result of single injury operating mode of second method respectively as shown in Figure 11～12; It can be seen that all single injury positioning results based on two kinds of damage positioning methods all successfully located default damage.

6) the damage reason location result of poly-injury operating mode

Using the two kinds of damage positioning methods proposed that damage regime 3 is detected: according to abovementioned steps (Fig. 3), when noise level 5%, the result based on the single injury operating mode of first method is distinguished as shown in Figure 10; Result based on the single injury operating mode of second method is distinguished as shown in figure 13; It can be seen that the poly-injury positioning result based on two kinds of damage positioning methods also all successfully located default damage.

7) conclusion

Above single injury, poly-injury operating mode damage reason location result all show that invent two kinds of suspension rod damage positioning methods can be used for the damage reason location of suspension rod preferably.

Claims (1)

1. the damage reason location system of suspension bridge and arch bridge suspender periodic detection, it is characterised in that this system is made up of stimulating module, data acquisition module, data analysis module, decision-making module;

Wherein stimulating module is be sequentially arranged on the measuring point of every suspension rod by a Wireless Acceleration Sensor, and firmly hammer is encouraged the measuring point of every suspension rod one by one and recorded the amplitude of pulse excitation by the force transducer in power hammer tip portion;

Data acquisition module gathers the pumping signal of force sensor and respectively from the acceleration signal that the Wireless Acceleration Sensor of suspension rod measuring point sends, and every suspension rod is gathered successively, and stores in a computer;

Data analysis module adopts two kinds of damage positioning methods of the suspension rod proposed be calculated and provide damage reason location result for pumping signal and the acceleration signal of all suspension rods collected;

Decision-making module displays whether damage suspension rod and the numbering of damage suspension rod, if not damaged suspension rod, then illustrates that all suspension rods are all safe; If there being damage suspension rod, re-using the physics lossless detection method suspension rod to damage and detecting, then make maintenance according to the seriousness of suspension rod damage or change the decision-making of suspension rod;

For the relation of sequencing between four modules: first encourage suspension rod; Then pumping signal and acceleration vibration response signal are gathered; Again the signal that all these collect is sent in data analysis module and is calculated by the two kinds of damage positioning method modules proposed; Result of calculation can display whether damage suspension rod and the numbering of damage suspension rod; Finally in decision-making module, it is again based on the physical detection tool and method suspension rod having damage to having found carry out degree of injury assessment and take final decision; Native system combines wholeness method and suspension rod is detected by local approach;

The first damage positioning method of suspension bridge and arch bridge suspender periodic detection, step is as follows:

Step one, measuring point and point of excitation are arranged: arrange a fixing measuring point and a fixing point of excitation on every suspension rod to be detected;

Step 2, acquisition acceleration responsive: the point of excitation at every suspension rod is firmly hammered into shape to encourage this suspension rod with suspension rod rope face vertical direction, and excitation amplitude recorded by the force transducer in power hammer tip portion simultaneously, and is transferred in the data acquisition module of computer; Data acquisition module is based respectively on the acceleration on the structure all measuring points of acquisition of the structure before damage and unknown state with excitation orientation equidirectional; Excitation amplitude is normalized by the acceleration signal obtained under different pulse excitation amplitudes, obtains the acceleration responsive under unit excitation amplitude (1N);

Step 3, calculate the correction logarithm acceleration energy of each measuring point acceleration responsive: acceleration time series (the signal a of measuring point on suspension rod k^k) each scatterplot beThen acceleration signal a^kCorrection logarithm acceleration energy MLAE be

$MLAE\left(a^k\right)=log\underset{i=1}{\overset{N-1}{\Σ}}{\left(a_i^k{a}_{i+1}^k\right)}^2---\left(1\right)$

Wherein log is common logarithm, and N is that signal is counted; Before and after damage, the acceleration responsive data length for calculating should be identical, selects complete pulse excitation acceleration responsive to be calculated; After obtaining the correction logarithm acceleration energy of each measuring point, connect these values and just can obtain revising logarithm acceleration energy waveform;

Logarithm acceleration energy waveform difference is revised in step 4, calculating: the correction logarithm acceleration energy difference D of measuring point place signal on suspension rod k before and after damage^kDefine as follows,

${\left(D^k\right)}_{rs}={\left({\mathrm{MLAE}}_{before}^k\right)}_r-{\left({\mathrm{MLAE}}_{after}^k\right)}_s---\left(2\right)$

Wherein (D^k)_rsThe D that the s response signal after being individual for the r before damaging and damaging is calculated^k,It is the correction logarithm accelerated energy value of r the response signal at measuring point place on the front suspension rod k of damage,It it is the correction logarithm accelerated energy value of s the response signal at measuring point place on damage rear suspension bar k;

Step 5, the correction logarithm acceleration energy difference D that all measuring point places are gone out based on a pair RESPONSE CALCULATION before damage and after damage^kBeing normalized, in identifying, maximum correction logarithm acceleration energy difference becomes 1 so every time; Correction logarithm acceleration energy difference after normalization is

${\left(D^k\right)}_{rs}^{*}={\left(D^k\right)}_{rs}/\underset{k}{max}\[{\left(D^k\right)}_{rs}\]---\left(3\right)$

To repeatedly encouraging the many groups acceleration of vibration collected to carry out step one to after the repeatedly calculating of step 5 in step 6, data analysis module, definition damage criterion is average normalized correction logarithm acceleration energy waveform difference; The damage criterion value such as following formula of measuring point on suspension rod k:

${\left(DI\right)}_k={\mathrm{\μ}}_k=\frac{1}{RS}\underset{r=1}{\overset{R}{\Σ}}\underset{s=1}{\overset{S}{\Σ}}{\left(D^k\right)}_{rs}^{*}---\left(4\right)$

Rule of thumb, RS >=10; The value of RS is the bigger the better;

Step 7, decision-making module: the average normalized correction logarithm acceleration energy difference μ at suspension rod measuring point place_kBe more than or equal to δ, this suspension rod is determined as damage suspension rod, namely

Damage suspension rod={ (DI)_k≥δ}(5)

Wherein δ is the threshold value introduced in order to avoid the appearance of false positive result; δ determines based on the damage reason location result of vibratory response data under lossless operating mode, and δ is a mean μ poorer than the normalization correction logarithm acceleration energy of lossless operating mode_kBigger value;

If there being damage suspension rod, using physics lossless detection method that the suspension rod of damage is detected, then making maintenance according to the seriousness of suspension rod damage or changing the decision-making of suspension rod;

The second damage positioning method of suspension bridge and arch bridge suspender periodic detection, step is as follows:

The step one of the second damage positioning method is identical with the first suspension bridge and arch bridge suspender periodic sensing approach to step 5; Thus obtain all measuring point place normalization damage characteristic differences of function

Step 6, determine that whether normalization damage characteristic function difference is be more than or equal to threshold value δ,

${\mathrm{\Γ}}_{rs}^k=H\left\{{\left(D_{\mathrm{\Δ}}^k\right)}_{rs}^{*}\right\}---\left(6\right)$

Wherein H () is Heaviside jump function, if the value that normalization damage characteristic function difference is be more than or equal to threshold value δ, H () is 1, otherwise its value is 0;δ herein is identical with the threshold value δ in formula (5); ;

Step 7, data analysis module observe each unit appearance situation in multi damage positioning result based on identifying of RS group data by being used for, in definition repeatedly identification, each unit accounts for the damage probability that percentage ratio is unit of total degree be more than or equal to the number of times of threshold value, and the damage probability of measuring point on suspension rod k is defined as the damage criterion (DI) of suspension rod k_k, its formula is as follows:

${\left(DI\right)}_k=\frac{1}{RS}\underset{r=1}{\overset{R}{\Σ}}\underset{s=1}{\overset{S}{\Σ}}{\mathrm{\Γ}}_{rs}^k---\left(7\right)$

Step 8, decision-making module: the damage probability unit be more than or equal to probability threshold value ρ is defined as damage unit, namely

Damage suspension rod={ (DI)_k≥ρ}(8)

Wherein ρ is probability threshold value, and the damage probability result based on lossless data is determined; If the damage probability of each unit is both less than ρ in the repeatedly recognition result of certain operating mode, then this operating mode is lossless operating mode;

If there being damage suspension rod, using physics lossless detection method that the suspension rod of damage is detected, then making maintenance according to the seriousness of suspension rod damage or changing the decision-making of suspension rod.