阅读说明：本技术 一种基于在线修正的桥式振弦应变计 (Bridge type vibrating wire strain gauge based on online correction ) 是由 雷升祥 王立新 李储军 汪珂 许和平 丁正全 邹春华 任晓春 张波 刘鹏 于 2019-09-30 设计创作，主要内容包括：本发明公开了一种基于在线修正的桥式振弦应变计,第一振弦固定于第一、第二固定端之间,第二振弦固定于第二、第三固定端之间,第三振弦固定于第四、第五固定端之间,第四振弦固定于第五、第六固定端之间,第一振弦上设置可引发激振的第一激振电磁线圈,第二振弦上设置可引发激振的第二激振电磁线圈,第三振弦上设置可引发激振的第三激振电磁线圈,第四振弦上设置可引发激振的第四激振电磁线圈,检测仪器分别与第一、第二、第三及第四激振电磁线圈相连接,第一与第二电磁线圈串联、第三与第四电磁线圈串联,这两部分串联结构组成并联结构,四部分激振电磁线圈为对称关系,可有效提高应变计灵敏性、精度、抗干扰能力及测量数据有效性。(The invention discloses a bridge type vibrating wire strain gauge based on-line correction, wherein a first vibrating wire is fixed between a first fixed end and a second fixed end, a second vibrating wire is fixed between the second fixed end and a third fixed end, a third vibrating wire is fixed between a fourth fixed end and a fifth fixed end, a fourth vibrating wire is fixed between the fifth fixed end and a sixth fixed end, a first excitation electromagnetic coil capable of initiating excitation is arranged on the first vibrating wire, a second excitation electromagnetic coil capable of initiating excitation is arranged on the second vibrating wire, a third excitation electromagnetic coil capable of initiating excitation is arranged on the third vibrating wire, a fourth excitation electromagnetic coil capable of initiating excitation is arranged on the fourth vibrating wire, a detection instrument is respectively connected with the first excitation electromagnetic coil, the second excitation electromagnetic coil, the third excitation electromagnetic coil and the fourth excitation electromagnetic coil, the first excitation electromagnetic coil is connected with the second excitation electromagnetic coil in series, the third excitation electromagnetic coil is connected with the fourth excitation electromagnetic coil in series, the two excitation electromagnetic coils form a parallel structure, and the, the sensitivity, the precision, the anti-interference capability and the measured data effectiveness of the strain gauge can be effectively improved.)

1. A bridge type vibrating wire strain gauge based on online correction is characterized by comprising a first fixed end (20), a second fixed end (21), a third fixed end (22), a fourth fixed end (23), a fifth fixed end (24), a sixth fixed end (25), a first vibrating wire (10), a second vibrating wire (11), a third vibrating wire (12), a fourth vibrating wire (13) and a detection module (4);

the first fixed end (20), the second fixed end (21) and the third fixed end (22) are uniformly distributed in the middle and on two sides, the first vibrating string (10) is fixed between the first fixed end (20) and the second fixed end (21), the second vibrating string (11) is fixed between the second fixed end (21) and the third fixed end (22), the fourth fixed end (23), the fifth fixed end (24) and the sixth fixed end (25) are uniformly distributed in the middle and on two sides, the third vibrating string (12) is fixed between the fourth fixed end (23) and the fifth fixed end (24), the fourth vibrating string (13) is fixed between the fifth fixed end (24) and the sixth fixed end (25), the fixed devices are fixed on the same base, the first vibrating string (10) is provided with a first exciting electromagnetic coil (30) for exciting the first vibrating string (10), and the second vibrating string (11) is provided with a second electromagnetic coil (31) for exciting the second vibrating string (11) The third vibrating wire (12) is provided with a third exciting electromagnetic coil (32) for exciting the third vibrating wire (12), the fourth vibrating wire (13) is provided with a fourth exciting electromagnetic coil (33) for exciting the fourth vibrating wire (13), and the detection module (4) is respectively connected with the first exciting electromagnetic coil (30), the second exciting electromagnetic coil (31), the third exciting electromagnetic coil (32) and the fourth exciting electromagnetic coil (33).

2. The bridge vibrating wire strain gauge based on online correction as claimed in claim 1, wherein the lengths, materials and elastic moduli of the first vibrating wire (10), the second vibrating wire (11), the third vibrating wire (12) and the fourth vibrating wire (13) are all the same, so that the characteristics of the four vibrating wires and the consistency of subsequent sampling data can be ensured.

3. The bridge vibrating wire strain gauge based on online correction of claim 1, wherein the first vibrating wire (10) and the first fixed end (20) and the second fixed end (21), the second vibrating wire (11) and the second fixed end (21) and the third fixed end (22), the third vibrating wire (12) and the fourth fixed end (23) and the fifth fixed end (24), and the fourth vibrating wire (13) and the fifth fixed end (24) and the sixth fixed end (25) are fixedly connected through a threaded fastener (7), and the fixed devices are fixed on the same base.

4. The on-line correction-based bridge vibratory wire strain gauge of claim 1 wherein the first excitation solenoid (30), the second excitation solenoid (31), the third excitation solenoid (32) and the fourth excitation solenoid (33) are connected in series-parallel.

5. The bridge vibrating wire strain gauge based on online correction as claimed in claim 4, wherein the series-parallel connection mode is as follows: the first excitation electromagnetic coil (30) and the second excitation electromagnetic coil (31) are connected in series, the third excitation electromagnetic coil (32) and the fourth excitation electromagnetic coil (33) are connected in series, and the two series structures jointly form a parallel structure.

6. The on-line correction-based vibrating wire bridge strain gauge according to claim 1, wherein the process of acquiring the true vibration frequency of the first vibrating wire (10) is as follows:

1) measuring the length l and the cross-sectional area s of the first vibrating wire (10);

2) tensioning the first vibrating wire (10) and measuring the initial vibration frequency f of the first vibrating wire (10)₀；

3) Applying a constant external force F to the first vibrating wire (10) by means of a first exciting electromagnetic coil (30)₁So that the first vibrating wire (10) generates a vibration signal, and after a time delta t, the vibration frequency f of the first vibrating wire (10) is remeasured, assuming thatThe result of (A) is K, then

Wherein the content of the first and second substances,the variation of the length of the first vibrating wire (10), e is the elastic modulus of the first vibrating wire (10), and m is the mass of the first vibrating wire (10);

4) repeating the experimental operation for multiple times, applying different constant external forces to the first vibrating wire (10) at different time intervals delta t, calculating K values corresponding to the time intervals delta t when the first vibrating wire (10) applies different external forces, and listing the K values obtained under different conditions in the same table;

5) according to a known constant external force F₁And the corresponding K value is obtained by the interval time in a table look-up mode, so that the real vibration frequency of the first vibrating wire (10)Comprises the following steps:

6) and searching a corresponding numerical value in the table according to the numerical value returned by the detection instrument, so that the range of the returned numerical value is judged according to the returned numerical value, and the returned measurement data is corrected online in real time according to the table searching result.

Technical Field

The invention relates to a bridge type vibrating wire strain gauge, in particular to a bridge type vibrating wire strain gauge based on online correction.

Background

The vibrating string strain gauge is one common structure strain monitoring device for engineering and has the advantages of simple structure, reliable operation, standard output signal and convenient computer processing. However, because the working environment of the traditional vibrating wire strain gauge is complex, in the practical application process, the sensitivity of the strain gauge and the measurement precision of data are affected by the interference of the external environment, and meanwhile, the problems of low data sampling rate and few sampling points exist, and as time goes on, the vibrating wire strain gauge generally has the problem that the precision of the measured vibration signal parameter is reduced due to vibrating wire aging or vibrating wire plasticity deterioration, and due to the influence of the factors, the accuracy and the validity of the data are reduced.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides the bridge vibrating wire strain gauge based on online correction, the strain gauge has strong anti-interference capability and high sensitivity, and the precision, the sampling rate and the number of sampling points of data are improved to a certain extent, so that the measured data are more accurate and effective.

In order to achieve the purpose, the bridge type vibrating wire strain gauge based on online correction comprises a first fixed end, a second fixed end, a third fixed end, a fourth fixed end, a fifth fixed end, a sixth fixed end, a first vibrating wire, a second vibrating wire, a third vibrating wire, a fourth vibrating wire and a detection instrument;

the first fixed end, the second fixed end and the third fixed end are uniformly distributed in the middle and on two sides, the first vibrating string is fixed between the first fixed end and the second fixed end, the second vibrating string is fixed between the second fixed end and the third fixed end, the fourth fixed end, the fifth fixed end and the sixth fixed end are uniformly distributed in the middle and on two sides, the third vibrating string is fixed between the fourth fixed end and the fifth fixed end, the fourth vibrating string is fixed between the fifth fixed end and the sixth fixed end, the first vibrating string is provided with a first excitation electromagnetic coil for exciting the first vibrating string, the second vibrating string is provided with a second excitation electromagnetic coil for exciting the second vibrating string, the third vibrating string is provided with a third excitation electromagnetic coil for exciting the third vibrating string, the fourth vibrating string is provided with a fourth excitation electromagnetic coil for exciting the fourth vibrating string, and the detecting instrument and the first excitation electromagnetic coil are respectively, The second excitation electromagnetic coil, the third excitation electromagnetic coil and the fourth excitation electromagnetic coil are connected.

The lengths, materials and elastic moduli of the first vibrating wire, the second vibrating wire, the third vibrating wire and the fourth vibrating wire are the same, so that the characteristics of the four vibrating wires and the consistency of subsequent sampling data can be ensured.

The first vibrating wire and the first fixed end and the second fixed end, the second vibrating wire and the second fixed end and the third fixed end, the third vibrating wire and the fourth fixed end and the fifth fixed end, and the fourth vibrating wire and the fifth fixed end and the sixth fixed end are fixedly connected through threaded fasteners, and meanwhile, the fixing devices are fixed on the same base.

The first excitation electromagnetic coil, the second excitation electromagnetic coil, the third excitation electromagnetic coil and the fourth excitation electromagnetic coil are connected in series-parallel connection. The method comprises the following specific steps: the first excitation electromagnetic coil and the second excitation electromagnetic coil are connected in series, the third excitation electromagnetic coil and the fourth excitation electromagnetic coil are connected in series, and the two series structures jointly form a parallel structure, so that a bridge concept is formed. In the bridge-type structure, the four excitation electromagnetic coils generate excitation on different vibration strings together, so that the sampling point number and the sampling rate of data are improved, and meanwhile, the four excitation electromagnetic coils are in a symmetrical relation, so that the sensitivity of the strain gauge and the precision of measured data are effectively improved.

The process of acquiring the real vibration frequency of the first vibrating wire comprises the following steps:

1) measuring the length l and the section area s of the first vibrating wire;

2) tensioning the first vibrating wire and measuring the initial vibration frequency f of the first vibrating wire₀；

3) Applying a constant external force F to the first vibrating wire by the first exciting electromagnetic coil₁So that the first vibrating wire generates a vibration signal, and after a time Δ t, the vibration frequency f of the first vibrating wire is measured again, assuming thatThe result of (A) is K, then

Wherein the content of the first and second substances,the variation of the length of the first vibrating wire is shown, e is the elastic modulus of the first vibrating wire, and m is the mass of the first vibrating wire;

4) applying different constant external forces to the first vibrating wire at different time intervals delta t, calculating K values corresponding to the time intervals delta t when the first vibrating wire applies different external forces, and recording calculation results under different conditions in the same table;

5) according to a known constant external force F₁And obtaining a corresponding K value by the interval time in a table look-up mode, so that the real vibration frequency of the first vibrating wireComprises the following steps:

6) in practical engineering application, corresponding numerical values are searched in a table according to the numerical values returned by the detection instrument, so that the range of the returned numerical values is judged according to the returned numerical values, and the returned measurement data is corrected online in real time according to the table searching result.

The invention has the following beneficial effects:

when the bridge type vibrating wire strain gauge based on online correction is in specific operation, the detector respectively excites the first vibrating wire, the second vibrating wire, the third vibrating wire and the fourth vibrating wire through the first excitation electromagnetic coil, the second excitation electromagnetic coil, the third excitation electromagnetic coil and the fourth excitation electromagnetic coil, and measures vibration signals of the first vibrating wire, the second vibrating wire, the third vibrating wire and the fourth vibrating wire so as to improve the sampling frequency of the vibration signals and reduce the influence of interference signals of external environment on measurement results.

Furthermore, the invention realizes the online revision of the real vibration frequency of the vibrating wire through data calculation, reduces the high cost caused by replacing the vibrating wire of the strain gauge, greatly prolongs the service life of the vibrating wire strain gauge, is convenient and quick to use, and is suitable for being widely applied to the technical fields of bridge load test, health monitoring and the like.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a structural elevation of the present invention;

wherein 10 is a first vibrating wire, 11 is a second vibrating wire, 12 is a third vibrating wire, 13 is a fourth vibrating wire, 20 is a first fixed end, 21 is a second fixed end, 22 is a third fixed end, 23 is a fourth fixed end, 24 is a fifth fixed end, 25 is a sixth fixed end, 30 is a first excitation electromagnetic coil, 31 is a second excitation electromagnetic coil, 32 is a third excitation electromagnetic coil, 33 is a fourth excitation electromagnetic coil, 4 is a detecting instrument, and 7 is a threaded fastener.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings:

referring to fig. 1, the bridge vibrating wire strain gauge based on online correction according to the present invention includes a first fixed end 20, a second fixed end 21, a third fixed end 22, a fourth fixed end 23, a fifth fixed end 24, a sixth fixed end 25, a first vibrating wire 10, a second vibrating wire 11, a third vibrating wire 12, a fourth vibrating wire 13 and a detection instrument 4; the first fixed end 20, the second fixed end 21 and the third fixed end 22 are uniformly distributed in the middle and on two sides, the first vibrating wire 10 is fixed between the first fixed end 20 and the second fixed end 21, the second vibrating wire 11 is fixed between the second fixed end 21 and the third fixed end 22, the fourth fixed end 23, the fifth fixed end 24 and the sixth fixed end 25 are uniformly distributed in the middle and on two sides, the third vibrating wire 12 is fixed between the fourth fixed end 23 and the fifth fixed end 24, the fourth vibrating wire 13 is fixed between the fifth fixed end 24 and the sixth fixed end 25, the first vibrating wire 10 is provided with a first excitation electromagnetic coil 30 for exciting the first vibrating wire 10, the second vibrating wire 11 is provided with a second excitation electromagnetic coil 31 for exciting the second vibrating wire 11, the third vibrating wire 12 is provided with a third excitation electromagnetic coil 32 for exciting the third vibrating wire 12, the fourth exciting electromagnetic coil 33 for exciting the fourth vibrating wire 13 is arranged on the fourth vibrating wire 13, the detection device 4 is connected to a first excitation electromagnetic coil 30, a second excitation electromagnetic coil 31, a third excitation electromagnetic coil 32, and a fourth excitation electromagnetic coil 33, respectively.

The first vibrating wire 10 is fixedly connected with the first fixing end 20 and the second fixing end 21, the second vibrating wire 11 is fixedly connected with the second fixing end 21 and the third fixing end 22, the third vibrating wire 12 is fixedly connected with the fourth fixing end 23 and the fifth fixing end 24, and the fourth vibrating wire 13 is fixedly connected with the fifth fixing end 24 and the sixth fixing end 25 through the threaded fasteners 7, and meanwhile, the fixing devices are fixed on the same base.

Referring to fig. 1, the first vibrating wire 10, the second vibrating wire 11, the third vibrating wire 12 and the fourth vibrating wire 13 have the same length; the first excitation solenoid 30, the second excitation solenoid 31, the third excitation solenoid 32, and the fourth excitation solenoid 33 are connected in series-parallel. The method comprises the following specific steps: the first excitation electromagnetic coil 30 and the second excitation electromagnetic coil 31 are connected in series, the third excitation electromagnetic coil 32 and the fourth excitation electromagnetic coil 33 are connected in series, and the two series structures jointly form a parallel structure, so that the bridge type strain gauge is formed. In the bridge-type strain gauge, the four excitation electromagnetic coils generate excitation on different vibration strings together, so that the sampling point number and the sampling rate of data are improved, and meanwhile, the four excitation electromagnetic coils are in a symmetrical relation, so that the sensitivity of the strain gauge and the precision of measured data are effectively improved.

The process of obtaining the true vibration frequency of the first vibrating wire 10 is as follows:

1) measuring the length l and the cross-sectional area s of the first vibrating wire 10;

2) the first vibrating wire 10 is tensioned, and the initial vibration frequency f of the first vibrating wire 10 is measured₀；

3) The first vibrating wire 10 is applied with a constant external force F by the first exciting electromagnetic coil 30₁So that the first vibrating wire 10 generates a vibration signal, and after a time Δ t, the vibration frequency f of the first vibrating wire 10 is measured again, assuming thatThe result of (A) is K, then

Wherein the content of the first and second substances,the variation of the length of the first vibrating wire 10 is shown, e is the elastic modulus of the first vibrating wire 10, and m is the mass of the first vibrating wire 10;

4) under the same conditions, a constant external force F is applied again to the first vibrating wire 10 by the first exciting electromagnetic coil 30₂So that the first vibrating wire 10 generates a vibration signal, and calculates that the first vibrating wire 10 applies different external forces F₂While at the same timeK values corresponding to different time periods delta t are separated;

5) the above experimental procedure was repeated several times under the same conditions. That is, K values corresponding to different external forces applied to the first vibrating wire 10 by the first exciting solenoid 30 and spaced by different time periods Δ t are calculated, and values obtained in different cases are listed in a table. .

6) According to a known constant external force F₁And obtaining the corresponding K value by the interval time in a table look-up mode, so that the real vibration frequency of the first vibrating wire 10Comprises the following steps:

7) in practical engineering application, corresponding numerical values are searched in a table according to the numerical values returned by the detection instrument, so that the range of the returned numerical values is judged according to the returned numerical values, and the returned measurement data is corrected online in real time according to the table searching result.

The detection instrument 4 is used for exciting a first vibrating wire 10, a second vibrating wire 11, a third vibrating wire 12 and a fourth vibrating wire 13 with the same length through a first exciting electromagnetic coil 30, a second exciting electromagnetic coil 31, a third exciting electromagnetic coil 32 and a fourth exciting electromagnetic coil 33 respectively, and measuring vibration signals of the first vibrating wire 10, the second vibrating wire 11, the third vibrating wire 12 and the fourth vibrating wire 13 so as to improve the sampling frequency of the vibration signals and reduce the influence of interference signals of external environment on measurement results; the detection instrument 4 compares and correlates vibration signals of the first vibrating wire 10, the second vibrating wire 11, the third vibrating wire 12 and the fourth vibrating wire 13, parameters of the vibration signals include frequency, amplitude and attenuation parameters, and the correlation processing refers to addition, subtraction, multiplication and division of data and calculation according to a stress correlation function obtained through experiments, so that the sampling frequency of the vibration signals is improved, and the influence of external environment interference signals on measurement results is reduced.

The above embodiments are only used to further illustrate the bridge type vibrating wire strain gauge based on online correction of the present invention, but the present invention is not limited to the embodiments, and any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention fall within the protection scope of the technical solution of the present invention.