阅读说明：本技术 一种拉索缺陷主动导波阵列传感器及检测方法 (Active guided wave array sensor for inhaul cable defects and detection method ) 是由 秦石美 王兵见 程寿山 刘刚 张立业 黄建初 于 2019-10-16 设计创作，主要内容包括：本发明公开了一种拉索缺陷主动导波阵列传感器及检测方法,涉及桥梁工程设计技术领域,包括套筒和传感器测控阵列,所述传感器测控阵列设置在所述套筒内侧；所述传感器测控阵列包括沿圆周方向均匀布置的压电传感器PZT晶片。本发明中传感器外形为圆筒样式,与拉索外形相适应,传感器端部以及四周的橡胶用来阻隔外界声音,提高监测准确度；传感器外套采用钢套筒,可以屏蔽外部环境电磁与噪声干扰。订制不同尺寸,进行单股、多股和整束安装,安装在拉索锚固端,用于长期监测拉索损伤状况。(The invention discloses an active guided wave array sensor for inhaul cable defects and a detection method, and relates to the technical field of bridge engineering design, wherein the active guided wave array sensor comprises a sleeve and a sensor measurement and control array, wherein the sensor measurement and control array is arranged on the inner side of the sleeve; the sensor measurement and control array comprises piezoelectric sensor PZT wafers which are uniformly arranged along the circumferential direction. The sensor is in a cylindrical shape and is adaptive to the shape of the inhaul cable, and rubber at the end part and around the sensor is used for blocking external sound, so that the monitoring accuracy is improved; the sensor outer sleeve adopts the steel sleeve, can shield external environment electromagnetism and noise interference. Different sizes are customized, single-strand, multi-strand and whole-bundle installation is carried out, and the installation is installed at the cable anchoring end and is used for monitoring the cable damage condition for a long time.)

1. The active guided wave array sensor for the defects of the inhaul cables is characterized by comprising a sleeve and a sensor measurement and control array, wherein the sensor measurement and control array is arranged on the inner side of the sleeve;

the sensor measurement and control array comprises piezoelectric sensor PZT wafers which are uniformly arranged along the circumferential direction.

2. The active inhaul cable defect guided wave array sensor as claimed in claim 1, wherein the sleeve is made of stainless steel or other materials, and the inner side wall and the outer side wall of the sleeve are coated with anti-rust paint.

3. The active inhaul cable defect guided wave array sensor as claimed in claim 1, wherein the sleeve is provided with a wire guide groove and a wire insertion hole, the wire insertion hole is arranged along the radial direction of the sleeve, the wire guide groove is arranged along the inner side of the sleeve, and the wire insertion hole is communicated with the wire guide groove;

the lead groove is used for installing a lead connected with the PZT wafer of the piezoelectric sensor.

4. The active guided wave array sensor for the inhaul cable defects as claimed in claim 3, wherein the PZT wafer is connected with a lead through an alloy connecting arm; the wire inserting hole is an armored wire inserting hole.

5. The active guided wave array sensor for the inhaul cable defects according to claim 4, wherein a lead sheet is arranged between the PZT wafer and the alloy connecting arm, the lead sheet and the alloy connecting arm are welded or bonded, and the lead sheet and the PZT wafer are connected in a sticking mode.

6. The active inhaul cable defect guided wave array sensor as claimed in claim 1, wherein isolation layers are arranged on the outer side and two ends of the sensor sleeve, each isolation layer comprises a rubber layer and a wire mesh, and the rubber layer is arranged on the inner side of the wire mesh.

7. The method for testing the guy cable defect active guided wave array sensor is characterized by comprising the following steps of:

s1, mounting a sensor device, and respectively arranging an exciter excitation end and a sensor receiving end, wherein the exciter forms an array element signal in a signal matrix;

s2, the array element signal generated in the step S1 propagates along the guy cable body, and when the array element signal encounters a defect, a waveform mutation signal is generated;

and S3, the receiving end of the sensor receives the waveform mutation signal, quantifies the mutation signal and determines the defect position.

8. The method according to claim 7, wherein step S1 includes the following steps: the cable defect active guided wave array sensor is installed on a cable body of a cable, one piezoelectric sensor PZT wafer is selected to be used as an exciter for excitation, and other piezoelectric sensor PZT wafers are used as sensor receiving ends.

9. The method of claim 7, wherein step S1 includes:

the guy cable defect active guided wave array sensor and the magnetostrictive guided wave sensor array are combined for use, the guy cable defect active guided wave array sensor is used as an excitation end, and the magnetostrictive guided wave sensor array is used as a receiving end.

10. The method according to claim 8 or 9, wherein step S3 specifically comprises:

for a waveform sudden change signal generated by cable damage or expansion, the displacement at a position D from a sound source is estimated by adopting HF-RMS, namely:

a is the characteristic amplitude of the sound source; λ -acoustic wavelength; ξ -the attenuation produced per wavelength; d-distance of sensor and sound source location; u-displacement of the transducer and sound source position.

Technical Field

The invention relates to the technical field of bridge engineering, in particular to an active guided wave array sensor for inhaul cable defects and a detection method.

Background

Guy cables are key stressed components of cable bridges and are subjected to wind-induced vibration, temperature changes and corrosion in addition to load bearing. Cable member failures begin with single wire fatigue or corrosion cracking, evolving into a full bundle cable failure. The current main methods for detecting the defect state of the stay cable comprise: acoustic emission sensors, photoelectric sensors, capacitive sensors, manual detection, and the like; the states of the inhaul cables can be detected through the means, early warning is carried out, but the existing devices have the problems of inconvenient installation, easy interference of external environment, insufficient precision, high maintenance cost, unsuitability for long-term field monitoring and the like.

Disclosure of Invention

The invention aims to provide an active guided wave array sensor for inhaul cable defects and a detection method, so that the problems in the prior art are solved.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

an active guided wave array sensor for inhaul cable defects comprises a sleeve and a sensor measurement and control array, wherein the sensor measurement and control array is arranged on the inner side of the sleeve;

the sensor measurement and control array comprises piezoelectric sensor PZT wafers which are uniformly arranged along the circumferential direction.

Preferably, the sleeve is made of stainless steel or other materials, and the inner side wall and the outer side wall are coated with antirust paint.

Preferably, the sleeve is provided with a wire guide groove and a wire insertion hole, the wire insertion hole is arranged along the radial direction of the sleeve, the wire guide groove is arranged along the inner side of the sleeve, and the wire insertion hole is communicated with the wire guide groove;

the lead groove is used for installing a lead connected with the PZT wafer of the piezoelectric sensor.

Preferably, the PZT wafer of the piezoelectric sensor is connected with a lead through an alloy connecting arm; the wire inserting hole is an armored wire inserting hole.

Preferably, a lead sheet is arranged between the piezoelectric sensor PZT wafer and the alloy connecting arm, the lead sheet and the alloy connecting arm are welded or bonded, and the lead sheet and the PZT wafer are connected in a sticking manner.

Preferably, the outer side and the two ends of the sensor sleeve are provided with isolation layers, each isolation layer comprises a rubber layer and an iron wire, and the rubber layer is arranged on the inner side of the iron wire.

The invention also aims to provide a method for testing the defect of the stay cable, which comprises the following steps:

s1, mounting a sensor device, and respectively arranging an exciter excitation end and a sensor receiving end, wherein the exciter forms an array element signal in a signal matrix;

s2, the array element signal generated in the step S1 propagates along the guy cable body, and when the array element signal encounters a defect, a waveform mutation signal is generated;

and S3, the receiving end of the sensor receives the waveform mutation signal, quantifies the mutation signal and determines the defect position.

Preferably, step S1 includes the following: the cable defect active guided wave array sensor is installed on a cable body of a cable, one piezoelectric sensor PZT wafer is selected to be used as an exciter for excitation, and other piezoelectric sensor PZT wafers are used as sensor receiving ends.

Preferably, step S1 includes: the guy cable defect active guided wave array sensor and the magnetostrictive guided wave sensor array are combined for use, the guy cable defect active guided wave array sensor is used as an excitation end, and the magnetostrictive guided wave sensor array is used as a receiving end.

Preferably, step S3 specifically includes:

for a waveform sudden change signal generated by cable damage or expansion, the displacement at a position D from a sound source is estimated by adopting HF-RMS, namely:

a is the characteristic amplitude of the sound source; λ -acoustic wavelength; ξ -the attenuation produced per wavelength; d-distance of sensor and sound source location; u-displacement of the transducer and sound source position.

The invention has the beneficial effects that:

the PWASA shape provided by the invention is in a cylinder shape and is adaptive to the shape of the inhaul cable, and the rubber at the end part and around the sensor is used for blocking external sound, so that the monitoring accuracy is improved; the sensor outer sleeve adopts the steel sleeve, can shield external environment electromagnetism and noise interference. Nimble installation that is applicable to various actual conditions to customize not unidimensional, carry out single strand, stranded and whole bundle of installation, PWASA installs at cable anchor end for long-term monitoring cable damage condition. According to the cylindrical surface guided wave theory, when the number of the piezoelectric sensors arranged in the circumferential direction is larger than the highest mode number under the excitation frequency, the bending modes are inhibited due to destructive interference of all the bending modes, the influence of guided wave multi-mode and frequency dispersion characteristics is reduced, and the monitoring accuracy of the sensors is improved.

Drawings

FIG. 1 is a perspective isometric view of a cable defect active guided wave array sensor;

FIG. 2 is a front cross-sectional view of a cable defect active guided wave array sensor;

FIG. 3 is a side cross-sectional view of a cable defect active guided wave array sensor;

FIG. 4 is a top view of a cable defect active guided wave array sensor;

1. 2, designing a rubber sealing layer, 3, an armored wire inserting hole, 4, a rubber layer, 5, a sensor measurement and control array module, 6, a lead, 7, a lead groove, 8, an alloy connecting arm, 9 and a PZT wafer;

figure 5 is a guided wave array numerical solution process.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.