Ultrasonic guided wave testing method for steel components using cross-sectional symmetry

Abstract

The ultrasonic guided wave detection method of steel components using cross-sectional symmetry relates to the technical field of structural non-destructive testing. The present invention is to solve the problem that when inspecting steel components, it is difficult to extract damage information at a long distance from the guided wave signal, resulting in low accuracy in structural defect identification and positioning. The present invention sets at least two ultrasonic guided wave signal propagation paths on the surface of the steel component to be tested, and the starting points of all ultrasonic guided wave signal propagation paths are located at one cross-section of the steel component to be tested, and the end points are located at another cross-section. Each ultrasonic guided wave signal propagation path forms a symmetrical structure with at least one of the remaining ultrasonic guided wave signal propagation paths; it is judged whether the signals received at the end points of the two ultrasonic guided wave signal propagation paths that form a symmetrical structure with each other are the same. If so, the steel component to be tested is not damaged on the ultrasonic guided wave signal propagation path, otherwise, the steel component to be tested is damaged on one of the ultrasonic guided wave signal propagation paths.

Description

Technical Field

[0001] The invention belongs to the technical field of structural nondestructive testing, and in particular relates to the testing of steel components. Background Art

[0002] Ultrasonic guided waves are ultrasonic waves that can propagate in thin plates, pipes, rods and other structural components with limited boundaries. Compared with ultrasonic body waves, ultrasonic guided waves can propagate over long distances and large areas in the above structures. When encountering tiny defects or damage in the structure, in addition to the part that continues to propagate, the waves will also be scattered or reflected at the defects. Analyzing the characteristics of the above various source waves can identify tiny defects or damage in the structure. Further analysis can locate, quantify and even image the defects. The structural damage identification method based on ultrasonic guided waves is sensitive to local tiny defects in the structure. Compared with traditional ultrasonic non-destructive testing, it can detect a larger range and distance. It is one of the structural non-destructive testing methods that has received widespread attention, research and application.

[0003] Common steel components include angle steel, I-beam, channel steel and square steel tube, which are widely used in civil engineering. Although guided wave detection technology can detect a larger range and longer distance, in the actual engineering application process, due to the particularity of the cross-sectional form of structures such as angle steel, I-beam, square steel tube, etc., compared with plate and tube structures, the existence of corners makes the propagation of guided waves in the above steel components more complicated. In addition, the multimodality of guided waves themselves will cause a large amount of clutter in the received signal, which greatly increases the difficulty of extracting damage information at a long distance from the guided wave signal, resulting in reduced accuracy in structural defect identification and positioning, or even failure to identify damage. This problem greatly limits ultrasonic guided wave detection. In existing studies, there are methods of circumferentially distributing piezoelectric transducers and designing active transducer networks to achieve the excitation and reception of guided waves in square steel tubes, but these methods require a large number of piezoelectric transducers, which is not economical and difficult to apply in actual engineering. Summary of the invention

[0004] The present invention aims to solve the problem that when using guided wave detection technology to detect steel components, it is difficult to extract damage information at a long distance from the guided wave signal, resulting in low accuracy in structural defect identification and positioning. A steel component ultrasonic guided wave detection method using cross-sectional symmetry is provided.

[0005] The present invention includes two ultrasonic guided wave detection methods for steel components using cross-sectional symmetry.

[0006] The first approach includes the following steps:

[0007] Step 1: Setting the ultrasonic guided wave signal propagation path.

[0008] At least two ultrasonic guided wave signal propagation paths are arranged on the surface of the steel member to be measured, the starting points of all ultrasonic guided wave signal propagation paths are located at one cross section of the steel member to be measured, and the end points are located at another cross section, and each ultrasonic guided wave signal propagation path forms a symmetrical structure with at least one of the remaining ultrasonic guided wave signal propagation paths, and the symmetrical structure is an axisymmetric structure with the central axis of the cross section of the steel member to be measured as the axis of symmetry, or a centrosymmetric structure with the geometric center of the cross section of the steel member to be measured as the center of symmetry;

[0009] Step 2: Damage determination

[0010] It is determined whether the signals received at the end points of the two ultrasonic guided wave signal propagation paths that form a symmetrical structure are the same. If so, the steel structure under test is not damaged on the ultrasonic guided wave signal propagation path; otherwise, the steel structure under test is damaged on one of the ultrasonic guided wave signal propagation paths.

[0011] Furthermore, in the first scheme mentioned above, M excitation points are provided on the outer contour of a cross section, and the excitation points are used to set a transducer for exciting ultrasonic guided wave signals into the steel component under test, and N detection points are provided on the outer contour of another cross section, and the monitoring points are used to set a transducer for collecting ultrasonic guided wave signals in the steel component under test, and both M and N are positive integers and cannot be 1 at the same time.

[0012] The second option includes the following steps:

[0013] The following steps are involved:

[0014] Step 1: Setting the ultrasonic guided wave signal propagation path.

[0015] At least two ultrasonic guided wave signal propagation paths are arranged on the surface of the steel member to be measured, the starting point and the end point of the ultrasonic guided wave signal propagation paths are the same point, and the starting points of all ultrasonic guided wave signal propagation paths are located at a cross section of the steel member to be measured, and each ultrasonic guided wave signal propagation path forms a symmetrical structure with at least one of the remaining ultrasonic guided wave signal propagation paths, and the symmetrical structure is an axisymmetric structure with the central axis of the cross section of the steel member to be measured as the axis of symmetry, or a centrosymmetric structure with the geometric center of the cross section of the steel member to be measured as the center of symmetry;

[0016] Step 2: Damage determination

[0017] It is determined whether the signals received at the end points of the two ultrasonic guided wave signal propagation paths that form a symmetrical structure are the same. If so, the steel structure under test is not damaged on the ultrasonic guided wave signal propagation path; otherwise, the steel structure under test is damaged on one of the ultrasonic guided wave signal propagation paths.

[0018] Furthermore, in the above second solution, at least two detection points are provided on the outer contour of the cross section, and the detection points are provided for the transducer used for both exciting and receiving the ultrasonic guided wave signal.

[0019] Furthermore, in the above two schemes, when the steel member to be tested has damage on one of the ultrasonic guided wave signal propagation paths, the steel member ultrasonic guided wave detection method further includes a damage rough positioning step, which is as follows:

[0020] S1: Take two ultrasonic guided wave signal propagation paths that form a symmetrical structure and have different signals received at the end points as the primary selected paths, and judge whether there is an ultrasonic guided wave signal propagation path that forms a symmetrical structure with any of the primary selected paths on the surface of the steel member under test. If so, take the ultrasonic guided wave signal propagation path that forms a symmetrical structure with the primary selected path as the reference path, and then execute S2, otherwise execute S3.

[0021] S2: Determine whether the signals received at the reference path and the endpoint of the symmetrical primary path are the same. If they are different, the damage is located on the primary path, and the primary path is used as the damaged path. If they are the same, the damage is located on another primary path, and the other primary path is used as the damaged path.

[0022] S3: Determine whether at least one new ultrasonic guided wave signal propagation path can be added to the surface of the steel component under test, and whether all the newly added ultrasonic guided wave signal propagation paths form a symmetrical structure with a primary selected path. If yes, execute S4; otherwise, execute S5.

[0023] S4: at least one new ultrasonic guided wave signal propagation path is added on the surface of the steel component to be tested, and all the newly added ultrasonic guided wave signal propagation paths form a symmetrical structure with a primary selected path, and the newly added ultrasonic guided wave signal propagation path is used as the reference path, and then return to S2,

[0024] S5: Determine whether the starting point and the end point of the two preliminary selected paths are at the same point. If yes, execute S6; otherwise, execute S7.

[0025] S6: Set the turning points of the two preliminary selected paths as the end points of the preliminary selected paths and set the transducers to collect the signals received by the two end points, and then execute S7.

[0026] S7: Exchange the end point and the starting point of each preliminary selected path, and collect the signal received by the end point.

[0027] Determine whether the signals received by the two end points of the same primary path before and after the exchange are the same. If so, the primary path is not damaged; otherwise, the primary path is damaged.

[0028] Furthermore, after determining the damage path, the steel component ultrasonic guided wave detection method further includes a damage precise positioning step, which is as follows:

[0029] Subtract the signals received at the two primary path endpoints to obtain a difference signal and draw a waveform curve of the difference signal.

[0030] The time corresponding to the wave packet of the waveform curve is multiplied by the wave velocity to obtain the damage distance.

[0031] From the starting point of the damage path to the damage distance along the damage path, the stopping point is the damage location

[0032] Compared with traditional methods, the ultrasonic guided wave detection method for steel components utilizing cross-sectional symmetry proposed in the present invention uses fewer piezoelectric transducers, has a simple installation method, and is easy to implement in actual engineering. The data analysis method is simple, and the influence of clutter in the signal can be reduced by subtracting differences or calculating correlation, and information such as the location and degree of damage can be obtained. The present invention can mainly be applied to steel components with symmetrical cross-sections, such as angle steels, I-beams, and square steel pipes. The present invention utilizes the symmetry of the above-mentioned types of cross-sections, symmetrically arranges ultrasonic guided wave transducers on the steel components, and extracts damage information by comparing and analyzing signals at symmetrical positions, thereby realizing damage detection of the above-mentioned steel components. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the location of the section selected on the steel member to be measured;

[0034] Figure 2 It is a schematic diagram of arranging the transducer on a cross section of a square steel tube;

[0035] Figure 3 The schematic diagram of arranging the transducer on a cross section of the angle steel;

[0036] Figure 4 It is a schematic diagram of arranging the transducer on a cross section of an I-beam;

[0037] Figure 5 Schematic diagram of setting the ultrasonic guided wave signal propagation path on the surface of a square steel tube, where (a) indicates that there are two cross sections on the square steel tube, and (b) indicates that there is one cross section on the square steel tube;

[0038] Figure 6 The waveform diagram of the symmetrical difference signal obtained by numerical simulation;

[0039] Figure 7 Schematic diagram of the test system involved in the test of the present invention;

[0040] Figure 8The waveform diagram of the circular hole damage difference signal obtained in the experiment, (a) represents the lossless difference signal, and (b) represents the symmetrical difference signal. DETAILED DESCRIPTION

[0041] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0042] Specific implementation method 1: refer to Figures 1 to 8 Specifically describing this embodiment, the ultrasonic guided wave detection method for steel components using cross-sectional symmetry described in this embodiment comprises the following steps:

[0043] Step 1: Setting the ultrasonic guided wave signal propagation path.

[0044] like Figure 5 As shown in (a), at least two ultrasonic guided wave signal propagation paths are set on the surface of the steel component 1 to be measured, and the starting points of all ultrasonic guided wave signal propagation paths are located at the first cross section 2 of the steel component 1 to be measured, and the end points are located at the second cross section 3. M excitation points are set on the outer contour of the first cross section 2, and the excitation points are used to set the transducer that excites the ultrasonic guided wave signal into the steel component 1 to be measured. N detection points are set on the outer contour of the second cross section 3, and the detection points are used to set the transducer that collects the ultrasonic guided wave signal in the steel component 1 to be measured. The M and N are both positive integers and cannot be 1 at the same time. Figure 2 As shown, the values ​​of M and N are 6; Figure 3 As shown, M and N take the values ​​of 2; Figure 4 As shown, the values ​​of M and N are 4.

[0045] Each ultrasonic guided wave signal propagation path forms a symmetrical structure with at least one of the remaining ultrasonic guided wave signal propagation paths, and the symmetrical structure is an axisymmetric structure with the central axis of the cross section of the measured steel component as the axis of symmetry, or a central symmetric structure with the geometric center of the cross section of the measured steel component as the center of symmetry.

[0046] Step 2: Damage determination

[0047] Determine whether the signals received at the end points of the two ultrasonic guided wave signal propagation paths that form a symmetrical structure are the same. If so, the steel component 1 under test is not damaged on the ultrasonic guided wave signal propagation path; otherwise, the steel component 1 under test is damaged on one of the ultrasonic guided wave signal propagation paths, and then execute step three.

[0048] Step 3: Rough damage location,

[0049] When the steel structure under test has damage on one of the ultrasonic guided wave signal propagation paths, the steps for rough damage location are as follows:

[0050] S1: Take two ultrasonic guided wave signal propagation paths that form a symmetrical structure and have different signals received at the end points as preliminary paths, and determine whether there is an ultrasonic guided wave signal propagation path on the surface of the steel member under test that forms a symmetrical structure with any of the preliminary paths. If so, take the ultrasonic guided wave signal propagation path that forms a symmetrical structure with the preliminary path as the reference path, and then execute S2, otherwise execute S3.

[0051] S2: Determine whether the signals received at the end point of the reference path and the primary path symmetrical thereto are the same. If they are different, the damage is located on the primary path, and the primary path is used as the damaged path. If they are the same, the damage is located on another primary path, and the other primary path is used as the damaged path, and then execute step 4.

[0052] S3: Determine whether at least one new ultrasonic guided wave signal propagation path can be added to the surface of the steel component under test, and whether all the newly added ultrasonic guided wave signal propagation paths form a symmetrical structure with a primary selected path. If so, execute S4; otherwise, execute S5.

[0053] S4: at least one new ultrasonic guided wave signal propagation path is added on the surface of the steel component under test, and all the newly added ultrasonic guided wave signal propagation paths form a symmetrical structure with a primary selected path, and the newly added ultrasonic guided wave signal propagation path is used as a reference path, and then return to S2.

[0054] S5: The end point and the starting point of each preliminary selected path are exchanged, and the signal received by the end point is collected to determine whether the signals received by the two end points of the same preliminary selected path before and after the exchange are the same. If so, the preliminary selected path is not damaged, otherwise, the preliminary selected path is damaged, and the preliminary selected path is used as a damaged path, and then step 4 is executed.

[0055] Step 4: Accurately locate the damage.

[0056] After the damage path is determined, the damage precise positioning steps are as follows:

[0057] Subtract the signals received at the two primary path endpoints to obtain a difference signal and draw a waveform curve of the difference signal.

[0058] The time corresponding to the wave packet of the waveform curve is multiplied by the wave velocity to obtain the damage distance.

[0059] The damage path is traveled from the starting point to the damage distance along the damage path, and the stopping point is the location where the damage occurs.

[0060] Specific implementation method 2: refer to Figures 2 to 8 Specifically describing this embodiment, the ultrasonic guided wave detection method for steel components using cross-sectional symmetry described in this embodiment is characterized in that the method comprises the following steps:

[0061] Step 1: Setting the ultrasonic guided wave signal propagation path.

[0062] like Figure 5 As shown in (b), at least two ultrasonic guided wave signal propagation paths are set on the surface of the steel member 1 to be tested, the starting point and the end point of the ultrasonic guided wave signal propagation path are the same point, and the starting points of all ultrasonic guided wave signal propagation paths are located at a cross section of the steel member to be tested, and each ultrasonic guided wave signal propagation path forms a symmetrical structure with at least one of the remaining ultrasonic guided wave signal propagation paths, and the symmetrical structure is an axisymmetric structure with the central axis of the cross section of the steel member to be tested as the axis of symmetry, or a central symmetrical structure with the geometric center of the cross section of the steel member to be tested as the center of symmetry. Figure 2 , 3 As shown in FIG. 4 , 6, 2, and 4 detection points are arranged on the outer contour of the cross section, and the detection points are arranged to be used for both exciting and receiving transducers of ultrasonic guided wave signals.

[0063] Step 2: Damage determination

[0064] Determine whether the signals received at the end points of the two ultrasonic guided wave signal propagation paths that form a symmetrical structure are the same. If so, the steel structure under test is not damaged on the ultrasonic guided wave signal propagation path; otherwise, the steel structure under test is damaged on one of the ultrasonic guided wave signal propagation paths, and then execute step three.

[0065] Step 3: Rough damage location,

[0066] When the steel member to be tested has damage on a propagation path of the ultrasonic guided wave signal, the ultrasonic guided wave detection method for steel members further includes a damage rough positioning step as follows:

[0067] S1: Take two ultrasonic guided wave signal propagation paths that form a symmetrical structure and have different signals received at the end points as the primary selected paths, and judge whether there is an ultrasonic guided wave signal propagation path that forms a symmetrical structure with any of the primary selected paths on the surface of the steel member under test. If so, take the ultrasonic guided wave signal propagation path that forms a symmetrical structure with the primary selected path as the reference path, and then execute S2, otherwise execute S3.

[0068] S2: Determine whether the signals received at the reference path and the endpoint of the symmetrical primary path are the same. If they are different, the damage is located on the primary path, and the primary path is used as the damaged path. If they are the same, the damage is located on another primary path, and the other primary path is used as the damaged path.

[0069] S3: Determine whether at least one new ultrasonic guided wave signal propagation path can be added to the surface of the steel component under test, and whether all the newly added ultrasonic guided wave signal propagation paths form a symmetrical structure with a primary selected path. If yes, execute S4; otherwise, execute S5.

[0070] S4: at least one new ultrasonic guided wave signal propagation path is added on the surface of the steel component to be tested, and all the newly added ultrasonic guided wave signal propagation paths form a symmetrical structure with a primary selected path, and the newly added ultrasonic guided wave signal propagation path is used as the reference path, and then return to S2,

[0071] S5: Set the turning points of the two preliminary selected paths as the end points of the preliminary selected paths and set the transducers to collect the signals received by the two end points, and then execute S6.

[0072] S6: Exchange the end point and the starting point of each preliminary selected path, and collect the signal received by the end point.

[0073] Determine whether the signals received by the two end points of the same preliminary path before and after the exchange are the same. If so, the preliminary path is not damaged. Otherwise, the preliminary path is damaged, and then execute step 4.

[0074] Step 4: Accurately locate the damage.

[0075] After determining the damage path, the steel component ultrasonic guided wave detection method further includes a damage precise positioning step, which is as follows:

[0076] Subtract the signals received at the two primary path endpoints to obtain a difference signal and draw a waveform curve of the difference signal.

[0077] The time corresponding to the wave packet of the waveform curve is multiplied by the wave velocity to obtain the damage distance.

[0078] The damage path is traveled from the starting point to the damage distance along the damage path, and the stopping point is the location where the damage occurs.

[0079] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. A method for ultrasonic guided wave detection of steel components using cross-sectional symmetry, characterized in that: The method comprises the following steps: Step 1: Setting the ultrasonic guided wave signal propagation path. At least two ultrasonic guided wave signal propagation paths are arranged on the surface of the steel member to be measured, the starting points of all ultrasonic guided wave signal propagation paths are located at one cross section of the steel member to be measured, and the end points are located at another cross section, and each ultrasonic guided wave signal propagation path forms a symmetrical structure with at least one of the remaining ultrasonic guided wave signal propagation paths, and the symmetrical structure is an axisymmetric structure with the central axis of the cross section of the steel member to be measured as the axis of symmetry, or a centrosymmetric structure with the geometric center of the cross section of the steel member to be measured as the center of symmetry; Step 2: Damage determination Determine whether the signals received at the end points of the two ultrasonic guided wave signal propagation paths that form a symmetrical structure are the same. If yes, the steel structure under test is not damaged on the ultrasonic guided wave signal propagation path; otherwise, the steel structure under test is damaged on one of the ultrasonic guided wave signal propagation paths; When the steel member to be tested has damage on a propagation path of the ultrasonic guided wave signal, the steel member ultrasonic guided wave detection method further includes a damage rough positioning step, which is specifically as follows: S1: Take two ultrasonic guided wave signal propagation paths that form a symmetrical structure and have different signals received at the end points as the primary selected paths, and judge whether there is an ultrasonic guided wave signal propagation path that forms a symmetrical structure with any of the primary selected paths on the surface of the steel member under test. If so, take the ultrasonic guided wave signal propagation path that forms a symmetrical structure with the primary selected path as the reference path, and then execute S2, otherwise execute S3. S2: Determine whether the signals received at the reference path and the endpoint of the symmetrical primary path are the same. If they are different, the damage is located on the primary path, and the primary path is used as the damaged path. If they are the same, the damage is located on another primary path, and the other primary path is used as the damaged path. S3: Determine whether at least one new ultrasonic guided wave signal propagation path can be added to the surface of the steel component under test, and whether all the newly added ultrasonic guided wave signal propagation paths form a symmetrical structure with a primary selected path. If yes, execute S4; otherwise, execute S5. S4: at least one new ultrasonic guided wave signal propagation path is added on the surface of the steel component to be tested, and all the newly added ultrasonic guided wave signal propagation paths form a symmetrical structure with a primary selected path, and the newly added ultrasonic guided wave signal propagation path is used as the reference path, and then return to S2, S5: Determine whether the starting point and the end point of the two preliminary selected paths are at the same point. If yes, execute S6; otherwise, execute S7. S6: Set the turning points of the two preliminary selected paths as the end points of the preliminary selected paths and set the transducers to collect the signals received by the two end points, and then execute S7. S7: Exchange the end point and the starting point of each preliminary selected path, and collect the signal received by the end point. It is determined whether the signals received by the two end points of the same preliminary path before and after the exchange are the same. If so, the preliminary path is not damaged. Otherwise, the preliminary path is damaged and is regarded as a damaged path.

2. The ultrasonic guided wave detection method for steel components using cross-sectional symmetry according to claim 1, characterized in that: M excitation points are provided on the outer contour of one cross section, and the excitation points are used to set a transducer for exciting ultrasonic guided wave signals into the steel component under test. N detection points are provided on the outer contour of the other cross section, and the detection points are used to set a transducer for collecting ultrasonic guided wave signals in the steel component under test. Both M and N are positive integers and cannot be 1 at the same time.

3. The ultrasonic guided wave detection method for steel components using cross-sectional symmetry according to claim 1, characterized in that: After determining the damage path, the steel component ultrasonic guided wave detection method further includes a damage precise positioning step, which is as follows: Subtract the signals received at the two primary path endpoints to obtain a difference signal and draw a waveform curve of the difference signal. The time corresponding to the wave packet of the waveform curve is multiplied by the wave velocity to obtain the damage distance. The damage path is traveled from the starting point to the damage distance along the damage path, and the stopping point is the location where the damage occurs.

4. The ultrasonic guided wave detection method for steel components using cross-sectional symmetry is characterized in that: The method comprises the following steps: Step 1: Setting the ultrasonic guided wave signal propagation path. At least two ultrasonic guided wave signal propagation paths are arranged on the surface of the steel member to be measured, the starting point and the end point of the ultrasonic guided wave signal propagation paths are the same point, and the starting points of all ultrasonic guided wave signal propagation paths are located at a cross section of the steel member to be measured, and each ultrasonic guided wave signal propagation path forms a symmetrical structure with at least one of the remaining ultrasonic guided wave signal propagation paths, and the symmetrical structure is an axisymmetric structure with the central axis of the cross section of the steel member to be measured as the axis of symmetry, or a centrosymmetric structure with the geometric center of the cross section of the steel member to be measured as the center of symmetry; Step 2: Damage determination Determine whether the signals received at the end points of the two ultrasonic guided wave signal propagation paths that form a symmetrical structure are the same. If yes, the steel structure under test is not damaged on the ultrasonic guided wave signal propagation path; otherwise, the steel structure under test is damaged on one of the ultrasonic guided wave signal propagation paths; When the steel member to be tested has damage on a propagation path of the ultrasonic guided wave signal, the steel member ultrasonic guided wave detection method further includes a damage rough positioning step, which is specifically as follows: S1: Take two ultrasonic guided wave signal propagation paths that form a symmetrical structure and have different signals received at the end points as the primary selected paths, and judge whether there is an ultrasonic guided wave signal propagation path that forms a symmetrical structure with any of the primary selected paths on the surface of the steel member under test. If so, take the ultrasonic guided wave signal propagation path that forms a symmetrical structure with the primary selected path as the reference path, and then execute S2, otherwise execute S3. S2: Determine whether the signals received at the reference path and the endpoint of the symmetrical primary path are the same. If they are different, the damage is located on the primary path, and the primary path is used as the damaged path. If they are the same, the damage is located on another primary path, and the other primary path is used as the damaged path. S3: Determine whether at least one new ultrasonic guided wave signal propagation path can be added to the surface of the steel component under test, and whether all the newly added ultrasonic guided wave signal propagation paths form a symmetrical structure with a primary selected path. If yes, execute S4; otherwise, execute S5. S4: at least one new ultrasonic guided wave signal propagation path is added on the surface of the steel component to be tested, and all the newly added ultrasonic guided wave signal propagation paths form a symmetrical structure with a primary selected path, and the newly added ultrasonic guided wave signal propagation path is used as the reference path, and then return to S2, S5: Determine whether the starting point and the end point of the two preliminary selected paths are at the same point. If yes, execute S6; otherwise, execute S7. S6: Set the turning points of the two preliminary selected paths as the end points of the preliminary selected paths and set the transducers to collect the signals received by the two end points, and then execute S7. S7: Exchange the end point and the starting point of each preliminary selected path, and collect the signal received by the end point. It is determined whether the signals received by the two end points of the same preliminary path before and after the exchange are the same. If so, the preliminary path is not damaged. Otherwise, the preliminary path is damaged and is regarded as a damaged path.

5. The ultrasonic guided wave detection method for steel components using cross-sectional symmetry according to claim 4, characterized in that: After determining the damage path, the steel component ultrasonic guided wave detection method further includes a damage precise positioning step, which is as follows: Subtract the signals received at the two primary path endpoints to obtain a difference signal and draw a waveform curve of the difference signal. The time corresponding to the wave packet of the waveform curve is multiplied by the wave velocity to obtain the damage distance. The damage path is traveled from the starting point to the damage distance along the damage path, and the stopping point is the location where the damage occurs.

6. The ultrasonic guided wave detection method for steel components using cross-sectional symmetry according to claim 4, characterized in that: At least two detection points are arranged on the outer contour of the cross section, and the detection points are provided with transducers used for both exciting and receiving ultrasonic guided wave signals.

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