阅读说明：本技术 一种基于超声导波方法的正交异性钢桥面板顶板疲劳裂纹检测系统 (Orthotropic steel bridge deck plate top plate fatigue crack detection system based on ultrasonic guided wave method ) 是由 周文松 李惠 王鹏 于 2019-09-27 设计创作，主要内容包括：一种基于超声导波方法的正交异性钢桥面板顶板疲劳裂纹检测系统,涉及无损检测与超声检测技术领域。本发明是为了解决现有正交异性钢桥面的检测时,难以在无损的情况下实现正交异性钢桥面板全面检测的问题。本发明所述的一种基于超声导波方法的正交异性钢桥面板顶板疲劳裂纹检测系统,在不损害待检测结构的情况下,通过支架在待测板面下自由行走,带动换能器检测任一位置,从而达到全面检测的目的。本发明可实现对目前目视难以检测的区域的疲劳裂纹无损、自动、准确、高效、定量的检出,为后续修复加固提供必要信息。(A system for detecting fatigue cracks of a top plate of an orthotropic steel bridge deck based on an ultrasonic guided wave method relates to the technical field of nondestructive testing and ultrasonic testing. The invention aims to solve the problem that the comprehensive detection of the orthotropic steel bridge deck is difficult to realize under the condition of no damage when the conventional orthotropic steel bridge deck is detected. The orthotropic steel bridge deck top plate fatigue crack detection system based on the ultrasonic guided wave method drives the transducer to detect any position by freely walking under the plate surface to be detected through the support under the condition of not damaging the structure to be detected, thereby achieving the aim of comprehensive detection. The invention can realize nondestructive, automatic, accurate, efficient and quantitative detection of fatigue cracks in the area which is difficult to detect visually at present, and provides necessary information for subsequent repair and reinforcement.)

1. A detection system for the fatigue cracks of a top plate of an orthotropic steel bridge deck plate based on an ultrasonic guided wave method is characterized in that,

comprises a detection part and a control part, wherein,

the detection section includes: a support and a transducer unit, the control portion comprising: the device comprises a signal transceiving unit, a control unit and a signal processing unit;

the support is used for carrying an energy converter unit and is adsorbed at the bottom of a steel box girder top plate (9) to be tested through a magnetic wheel set, so that the energy converter unit can be close to or cling to the bottom of the steel box girder top plate (9) to be tested and can be driven to move along the length direction of a U-shaped rib (10) of the steel box girder, the energy converter unit comprises at least one energy converter (51), and the energy converter (51) is used for exciting ultrasonic guided wave signals in the steel box girder top plate (9) to be tested and also used for receiving guided wave signals propagated in the steel box girder top plate (9) to be tested at different position points;

the signal transceiving unit includes:

a waveform generation module: used for generating a narrow-band voltage signal, applying the signal on a transducer (51) and exciting the signal in a top plate (9) of the steel box girder to be measured to form an ultrasonic guided wave signal,

a data acquisition module: used for collecting the guided wave signals received by the transducer (51) in real time and sending the guided wave signals to the signal processing unit,

a channel switching module: when the number of the transducers (51) is 1, switching the transducers (51) from a receiving guided wave signal state to an exciting ultrasonic guided wave signal state after the transducers (51) update the position points, and switching the transducers (51) from the exciting ultrasonic guided wave signal state to the receiving guided wave signal state after the transducers (51) excite the ultrasonic guided wave signals;

the control unit includes:

a driving module: the magnetic wheel set is used for driving the driving motor in the magnetic wheel set to rotate forward and backward and stop;

a signal processing unit: and the method is used for obtaining the crack position, the crack length and the crack depth by utilizing the guided wave signals at the continuous position points.

2. The system for detecting the fatigue crack of the top plate of the orthotropic steel bridge deck plate based on the ultrasonic guided wave method is characterized in that the bracket comprises a frame (1) and at least one transducer connecting rod (5), wherein the number of the transducer connecting rods (5) is the same as that of the transducers (51);

two groups of rod sets which are mirror-symmetrical are arranged on the frame (1), each group of rod sets comprises k wheel set connecting rods which are parallel to each other and are arranged along a straight line, k is a positive integer, the free end of each wheel set connecting rod is provided with a magnetic wheel set, the transducer connecting rod (5) is fixed on the frame (1) and is parallel to the wheel set connecting rods, the free end of each wheel set connecting rod is sleeved with a rigid limiting part (4), the rigid limiting parts (4) can move along the length direction of the wheel set connecting rods and can be locked on the wheel set connecting rods through locking devices, two rigid limiting parts (4) which are respectively positioned on two opposite wheel set connecting rods in the two rod sets are mirror-symmetrical, the two rigid limiting parts (4) are used for clamping two sides of a U-shaped rib (10) of the steel box girder, and the free end of each transducer connecting rod (5) is provided with, the holder (52) is used for holding the transducer (51).

3. The system for detecting the fatigue crack of the top plate of the orthotropic steel bridge deck based on the ultrasonic guided wave method is characterized in that k is 2, the frame (1) comprises at least one connecting beam (12) and two U-shaped frames (11), the two U-shaped frames (11) are arranged in a mirror symmetry mode, planes of the two U-shaped frames (11) are parallel to each other, the two U-shaped frames (11) are fixedly connected with each other through the connecting beam (12), the transducer connecting rod (5) is fixed on the connecting beam (12), and a rod at which the free end of each U-shaped frame (11) is located serves as a wheel set connecting rod.

4. The system for detecting the fatigue cracks of the top plate of the orthotropic steel bridge deck plate based on the ultrasonic guided wave method according to claim 2 or 3, wherein the rigid limiting member (4) comprises two rigid rods (41), a main beam (42) and a limiting collar (44), the two rigid rods (41) are fixed at two ends of the main beam (42) in a mirror symmetry manner, the limiting collar (44) is fixed at the midpoint of the main beam (42), the two rigid rods (41) and the limiting collar (44) are respectively located at two sides of the main beam (42) and are coplanar, and the plane is used as the plane where the rigid limiting member (4) is located,

the free ends of the two rigid rods (41) are respectively provided with a pulley (43), the main shaft of the pulley (43) is vertical to the plane of the rigid limiting piece (4),

the limiting lantern ring (44) is used for being sleeved on the wheel set connecting rod to enable the plane where the rigid limiting part (4) is located to be perpendicular to the wheel set connecting rod.

5. The system for detecting the fatigue cracks of the top plate of the orthotropic steel bridge deck plate based on the ultrasonic guided wave method is characterized in that the locking device is a fastening bolt (45), the fastening bolt (45) is in threaded connection with the limiting sleeve ring (44) and is arranged in the same direction as the rigid rod (41), and the length of the fastening bolt (45) is greater than the thickness of the wall of the limiting sleeve ring (44).

6. The system for detecting the fatigue crack of the top plate of the orthotropic steel bridge deck plate based on the ultrasonic guided wave method as claimed in claim 2, wherein the transducer connecting rod (5) is a telescopic hydraulic rod.

7. The system for detecting the fatigue crack of the top plate of the orthotropic steel bridge deck plate based on the ultrasonic guided wave method as claimed in claim 2, 3, 5 or 6, wherein the detection part further comprises a fall prevention unit, and the fall prevention unit comprises: the anti-falling magnetic seat (6), the safety rope (7) and the safety rope hook (8);

the anti-falling magnetic base (6) is used for being adsorbed at the bottom of a steel box girder top plate (9) to be tested, the anti-falling magnetic base (6) is connected with the safety rope hook (8) through the safety rope (7), and the safety rope hook (8) can be hung with the support.

8. The system for detecting the fatigue crack of the top plate of the orthotropic steel bridge deck plate based on the ultrasonic guided wave method as claimed in claim 2,

when k is 1, the magnetic wheel group is an active magnetic wheel group (2),

when k is more than 1, the magnetic wheel set has two types, one type is a driving magnetic wheel set (2), the other type is a driven magnetic wheel set (3),

the driving motor in the magnetic wheel set is positioned in the driving magnetic wheel set (2) and is used for driving the roller in the driving magnetic wheel set (2) to rotate so as to drive the support to move.

9. The system for detecting the fatigue crack of the top plate of the orthotropic steel bridge deck plate based on the ultrasonic guided wave method as claimed in claim 1, wherein the signal processing unit specifically comprises the following modules:

a correlation coefficient solving module: for solving the correlation coefficients of the guided wave signals at successive location points,

crack information solving module: and all guided wave signals corresponding to the region between the two position points are input into the crack depth recognition model to predict the crack depth.

10. The system for detecting the fatigue cracks of the top plate of the orthotropic steel bridge deck plate based on the ultrasonic guided wave method as claimed in claim 9, wherein in the crack information solving module,

firstly, collecting guided wave signals of different cracks and corresponding crack depths to form a crack depth database,

and then, training a crack depth recognition basic model by using a crack depth database to obtain a trained crack depth recognition model.

11. The system for detecting the fatigue crack of the top plate of the orthotropic steel bridge deck slab based on the ultrasonic guided wave method as claimed in claim 10, wherein the signal processing unit further comprises a model updating module, and the model updating module is used for storing the crack depth obtained in the crack information solving module and the guided wave signal corresponding to the crack depth into a crack depth database.

12. The system for detecting the fatigue crack of the top plate of the orthotropic steel bridge deck plate based on the ultrasonic guided wave method as claimed in claim 1, wherein the control part is fixed on a bracket.

Technical Field

The invention belongs to the technical field of nondestructive testing and ultrasonic testing, and particularly relates to a method for testing fatigue cracks of a top plate of a orthotropic steel bridge deck.

Background

Orthotropic steel bridge deck plates are increasingly widely applied to various bridge projects at home and abroad due to the advantages of excellent mechanical properties, use performance, economical efficiency and the like. However, due to the complex structure of the orthotropic steel bridge deck slab, the number of connecting and welding parts between the components is large, and in recent years, under the action of increasing traffic flow and overloaded vehicles, and under the action of factors such as the defects of the structure and welding residual stress, the fatigue problem of the orthotropic steel bridge deck slab is prominent, and the fatigue cracking problem is frequent. The fatigue cracks of the orthotropic steel bridge deck slab have the characteristics of universality, concealment, dispersibility and the like, and if the fatigue cracks are not treated in time after appearing, the fatigue cracks can be rapidly expanded and developed into large-size cracks, so that the service safety of the bridge is seriously threatened, and unpredictable accidents such as sudden bridge deck collapse and the like can be caused under severe conditions. The domestic and foreign bridge detection statistics show that fatigue cracks are found in the steel bridge deck as early as 5 years of traffic, and more serious orthotropic deck fatigue diseases appear in a plurality of steel bridges in China about 10 years of operation. The method has the advantages that the fatigue cracks of the orthotropic steel bridge deck are efficiently and accurately detected as soon as possible, and further reinforced and maintained, and the method has extremely important significance for guaranteeing the operation safety and the service life of the bridge.

Fatigue cracks in orthotropic steel decking are classified primarily by their location, exemplified by the currently most commonly used closed U-shaped stiffeners. Fig. 1 shows the main part structure of orthotropic steel bridge deck. Fatigue cracks mainly appear at the joint of the U-shaped rib and the top plate, the joint of the U-shaped rib and the transverse partition plate, the butt weld of the U-shaped rib, the U-shaped rib crack at the over-weld of the U-shaped rib, the joint of the transverse partition plate and the top plate and the like. Most of cracks belong to visible cracks, and the appearance visual inspection method is commonly used in field detection at present, namely, the positions and the characteristics of the cracks are recorded in the steel box girder in a mode of manual checking, marking, numbering, photographing and the like. However, the internal cracks of the closed U-shaped ribs were not found by visual inspection, and fatigue cracks were marked in fig. 2. For the fatigue crack of this type, a commonly used detection method in the current practical engineering is to open a bridge deck pavement layer outside a steel box girder, namely on a bridge deck, to expose a flat top surface of a steel plate (namely a top plate), and then to perform long-distance scanning on the steel plate along the weld line trend of a U rib and the top plate by using ultrasonic diffraction time difference method equipment (namely a TOFD ultrasonic flaw detector). The method needs to block traffic and destroy a pavement layer of the whole lane for detection, does not belong to nondestructive detection, and consumes a large amount of manpower, material resources and financial resources. In addition, ultrasonic phased array detection can be adopted for the fatigue cracks, but the ultrasonic phased array has the defects of too small scanning range, scanning blind areas, complex detection process, extremely low efficiency and the like. In addition, at present, no effective detection means is provided for invisible cracks at the top plate part of the orthotropic steel bridge deck.

Disclosure of Invention

The invention provides a system for detecting fatigue cracks of a top plate of an orthotropic steel bridge deck based on an ultrasonic guided wave method, aiming at solving the problem that the complete detection of the orthotropic steel bridge deck is difficult to realize under the condition of no damage when the conventional orthotropic steel bridge deck is detected.

An orthotropic steel bridge deck plate fatigue crack detection system based on an ultrasonic guided wave method comprises a detection part and a control part, wherein the detection part comprises: a support and a transducer unit, the control portion comprising: the device comprises a signal transceiving unit, a control unit and a signal processing unit;

the support is used for carrying an energy converter unit and is adsorbed at the bottom of the top plate 9 of the steel box girder to be measured through a magnetic wheel set, so that the energy converter unit can be close to or tightly attached to the bottom of the top plate 9 of the steel box girder to be measured and can be driven to move along the length direction of the U-shaped rib 10 of the steel box girder, the energy converter unit comprises at least one energy converter 51, and the energy converter 51 is used for exciting ultrasonic guided wave signals in the top plate 9 of the steel box girder to be measured and receiving guided wave signals propagated in the top plate 9 of the steel box girder to be measured at different position points;

the signal transceiving unit includes:

a waveform generation module: used for generating a narrow-band voltage signal, applying the signal on the transducer 51 and exciting the signal in the top plate 9 of the steel box girder to be measured to form an ultrasonic guided wave signal,

a data acquisition module: for collecting the guided wave signals received by the transducer 51 in real time and sending the guided wave signals to the signal processing unit,

a channel switching module: for switching the transducer 51 from the state of receiving guided wave signals to the state of exciting ultrasonic guided wave signals after the transducer 51 updates the position point when the number of the transducers 51 is 1, and switching the transducer 51 from the state of exciting ultrasonic guided wave signals to the state of receiving guided wave signals after the transducer 51 has excited ultrasonic guided wave signals;

the control unit includes:

a driving module: the magnetic wheel set is used for driving the driving motor in the magnetic wheel set to rotate forward and backward and stop;

a signal processing unit: and the method is used for obtaining the crack position, the crack length and the crack depth by utilizing the guided wave signals at the continuous position points.

Further, the bracket comprises a frame 1 and at least one transducer connecting rod 5, and the number of the transducer connecting rods 5 is the same as that of the transducers 51;

two sets of pole groups that are equipped with mirror symmetry on frame 1, every group pole group includes k and is parallel to each other, and the wheelset connecting rod of arranging along a straight line, k is the positive integer, the free end of every wheelset connecting rod all is equipped with a magnetic force wheelset, transducer connecting rod 5 is fixed on frame 1, and be parallel to each other with the wheelset connecting rod, a rigidity locating part 4 is all cup jointed to the free end of every wheelset connecting rod, rigidity locating part 4 can remove along wheelset connecting rod length direction, and can lock on the wheelset connecting rod through locking device, be located two relative two rigidity locating parts 4 mirror symmetry on two wheelset connecting rods in two pole groups respectively, these two rigidity locating parts 4 are used for the centre gripping in the both sides of steel box girder U type rib 10, the free end of every transducer connecting rod 5 all is equipped with a holder 52, holder 52 is used for.

Further, k 2, frame 1 includes at least one tie-beam 12 and two U-shaped framves 11, and 11 mirror symmetry of two U-shaped framves set up and the plane of place is parallel to each other, and two U-shaped framves 11 pass through the mutual fixed connection of tie-beam 12, and transducer connecting rod 5 is fixed on tie-beam 12, and the free end of U-shaped frame 11 is the pole as the wheelset connecting rod.

Further, the rigid position-limiting member 4 includes two rigid rods 41, a main beam 42 and a position-limiting collar 44, the two rigid rods 41 are fixed at two ends of the main beam 42 in a mirror symmetry manner, the position-limiting collar 44 is fixed at a midpoint of the main beam 42, the two rigid rods 41 and the position-limiting collar 44 are respectively located at two sides of the main beam 42 and are coplanar, the plane serves as a plane where the rigid position-limiting member 4 is located,

the free ends of the two rigid rods 41 are respectively provided with a pulley 43, the main shaft of the pulley 43 is vertical to the plane of the rigid limiting piece 4,

the limiting collar 44 is used for being sleeved on the wheel set connecting rod, so that the plane where the rigid limiting part 4 is located is perpendicular to the wheel set connecting rod.

Further, the locking device is a fastening bolt 45, the fastening bolt 45 is in threaded connection with the limiting collar 44 and is arranged in the same direction as the rigid rod 41, and the length of the fastening bolt 45 is larger than the thickness of the wall of the limiting collar 44.

Further, the transducer connecting rod 5 is a telescopic hydraulic rod.

Further, the detection part still includes the unit of preventing weighing down, the unit of preventing weighing down includes: the anti-falling magnetic seat 6, the safety rope 7 and the safety rope hook 8;

the anti-falling magnetic base 6 is used for being adsorbed at the bottom of a steel box girder top plate 9 to be tested, the anti-falling magnetic base 6 is connected with the safety rope hook 8 through the safety rope 7, and the safety rope hook 8 can be connected with the support in an articulated manner.

Furthermore, when k is 1, the magnetic wheel set is an active magnetic wheel set 2,

k is more than 1, the magnetic wheel set has two types, one type is a driving magnetic wheel set 2, the other type is a driven magnetic wheel set 3,

the driving motor in the magnetic wheel set is located in the driving magnetic wheel set 2 and is used for driving the roller in the driving magnetic wheel set 2 to rotate so as to drive the support to move.

Further, the signal processing unit specifically includes the following modules:

a correlation coefficient solving module: for solving the correlation coefficients of the guided wave signals at successive location points,

crack information solving module: and all guided wave signals corresponding to the region between the two position points are input into the crack depth recognition model to predict the crack depth.

Furthermore, in the crack information solving module,

firstly, collecting guided wave signals of different cracks and corresponding crack depths to form a crack depth database,

and then, training a crack depth recognition basic model by using a crack depth database to obtain a trained crack depth recognition model.

Further, the signal processing unit further comprises a model updating module, and the model updating module is used for storing the crack depth obtained in the crack information solving module and the guided wave signal corresponding to the crack depth into a crack depth database.

Further, the control part is fixed on the bracket.

Compared with the prior art, the invention has the following advantages:

the orthotropic steel bridge deck top plate fatigue crack detection system based on the ultrasonic guided wave method drives the transducer to detect any position by freely walking under the plate surface to be detected through the support under the condition of not damaging the structure to be detected, thereby achieving the aim of comprehensive detection. The fatigue crack identification method realizes more accurate fatigue crack identification by updating the signal processing and crack identification algorithm on the basis of the existing hardware; the invention can realize nondestructive, automatic, accurate, efficient and quantitative detection of fatigue cracks in the area which is difficult to detect visually at present, and provides necessary information for subsequent repair and reinforcement.

Drawings

Fig. 1 is a schematic structural view of an orthotropic steel bridge deck slab recorded in the background art, in which a longitudinal bridge direction is a longitudinal bridge direction, a transverse bridge direction is a transverse bridge direction, 9 steel box girder top plates, 10 steel box girder U-shaped ribs, 11 transverse partition plates and 12 fatigue cracks are formed;

FIG. 2 is a schematic view of the location of a fatigue crack in a typical closed U-shaped rib;

FIG. 3 is a schematic diagram of a system for detecting fatigue cracks of a top plate of an orthotropic steel bridge deck based on an ultrasonic guided wave method according to the present invention;

FIG. 4 is a schematic structural view of a stent;

FIG. 5 is a schematic structural view of the rigid spacing wheel of FIG. 4;

FIG. 6 is a schematic structural view of the sensor connecting rod of FIG. 4;

FIG. 7 is a schematic view of a three-dimensional structure of an orthotropic steel bridge deck plate fatigue crack detection system based on an ultrasonic guided wave method, which is provided by the invention, when the system is arranged at the bottom of a steel box girder;

FIG. 8 is a schematic end view of the orthotropic steel deck plate top plate fatigue crack detection system based on the ultrasonic guided wave method of FIG. 7 when the system is arranged at the bottom of a steel box girder;

FIG. 9 is a schematic structural view of the fall arrest unit;

fig. 10 is a schematic diagram of the working principle of the signal processing unit.

Detailed Description