Ultrasonic phased array tube socket fillet weld multiple calculation method and detection system

Abstract

The invention discloses an ultrasonic phased array tube socket fillet weld multiple wave calculation method, which comprises the following steps that 1, a scanning frame is arranged to adopt a three-axis scanning mode, an ultrasonic phased array instrument and a phased array probe are used for data acquisition, and the ultrasonic phased array instrument supports three-dimensional coding; 2, performing data acquisition by using an ultrasonic phased array instrument and a phased array probe to obtain an S scanning imaging picture of the current scanning section; 3, defining parameters, establishing three-dimensional rectangular coordinate systems Oxyz and O'x'y'z ', and solving a tube socket fillet weld intersecting line equation; 4, the minor semi-axis b is equal to the outer radius R of the mother pipe, and the major semi-axis a is obtained through calculation according to the intersection point of the pipe base fillet weld intersecting line and the ellipse; 5, solving an intersection point of the acoustic beam equation and the elliptic equation, calculating a reflection direction based on a reflection law, and determining a multiple wave path; and 6, repeating the step 5, calculating multiples, and outputting a result for defect analysis. The invention also discloses an ultrasonic phased array tube socket fillet weld multiple wave detection system.

Description

Technical Field

[0001] The present invention belongs to the technical field of ultrasonic nondestructive testing, and specifically relates to a multiple wave calculation method and a detection system for an ultrasonic phased array tube base fillet weld. Background Art

[0002] Pipe socket fillet welds are a common structure, widely used in boiler equipment, nuclear power pipelines, oil pipelines, and other fields. Because this structure is prone to stress concentration, any welding defects can easily expand during use, leading to weld cracking and failure. Therefore, defects within pipe socket fillet welds must be inspected during use.

[0003] In actual testing, due to the complex geometry of the tube socket fillet weld itself, conventional ultrasonic phased array testing methods are difficult to accurately and effectively perform nondestructive testing, and the location of defects cannot be accurately determined. Furthermore, the end of the branch pipe insertion section is prone to generating corner reflections, which interfere with normal defect detection and analysis, easily leading to missed detections and false detections. Therefore, for ultrasonic phased array nondestructive testing of tube socket fillet welds, accurately determining the defect location and distinguishing between true defects and corner reflections has always been a challenge for nondestructive testing. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide an ultrasonic phased array pipe socket fillet weld multiple wave calculation method and detection system, which can accurately plot multiple waves on the fan scan diagram, improve the efficiency and reliability of pipe socket fillet weld flaw detection, and solve the practical problems of previous fillet weld flaw detection that is highly dependent on the experience of engineering personnel and is prone to missed detection and false detection.

[0005] In order to achieve the above object, the present invention provides the following technical solutions: The present invention first proposes a method for calculating multiple waves of an ultrasonic phased array tube socket fillet weld, comprising the following steps: Step 1: Data Acquisition Preparation: Set up the scanning gantry using a three-axis scanning method. The probe is located on the main pipe. The first rotation axis controls the probe's rotation around the central axis of the branch pipe, the horizontal axis controls the probe's distance from the outer surface of the branch pipe, and the second rotation axis controls the probe's tilt angle. Data acquisition is performed using an ultrasonic phased array instrument and a phased array probe. The ultrasonic phased array instrument supports 3D encoding. Step 2: Data acquisition and imaging: Use ultrasonic phased array instruments and phased array probes to acquire data and obtain S-scan imaging images of the current scan section; Step 3: Calculate the intersection line equation of the pipe seat fillet weld: Define parameters including the main pipe wall thickness H, main pipe outer radius R, branch pipe wall thickness h, branch pipe outer diameter r, main pipe-branch welding angle α, probe rotation angle θ, and probe-branch outer surface distance d; establish three-dimensional rectangular coordinate systems Oxyz and O'x'y'z', where: Oxyz takes the intersection of the main pipe centerline and the branch pipe centerline as the origin and the main pipe centerline as the y-axis; O'x'y'z' takes the branch pipe centerline as the y'-axis; calculate the coordinate transformation equation from O'x'y'z' to Oxyz, and solve the main pipe outer wall equation and the branch pipe outer wall equation simultaneously to obtain the pipe seat fillet weld intersection line equation; Step 4: Calculate the ellipse equation of the current scan section: Establish a plane rectangular coordinate system O''x''y'' on the current scan section, where the y'' axis corresponds to the z-axis of Oxyz, and the x'' axis corresponds to the y-axis of Oxyz rotated -θ around the z-axis and then inverted; calculate the ellipse parameters through the coordinate system transformation from Oxyz to O''x''y''. The ellipse parameters include the major semi-axis a and the minor semi-axis b, where the minor semi-axis b is equal to the outer radius R of the mother pipe, and the major semi-axis a is calculated from the intersection of the pipe seat fillet weld intersection line and the ellipse; Step 5: Calculate the intersection of the sound beam and the ellipse and the reflection direction: Convert the starting point and direction of the sound beam to the coordinate system O''x''y'' and solve the intersection of the sound beam equation and the ellipse equation. Eliminate the intersection points that are not within the ellipse arc angle range and take the intersection point closest to the sound beam starting point. Calculate the reflection direction based on the reflection law to determine the multiple wave path. Step 6: Repeat step 5 to calculate multiple waves and output the results for defect analysis.

[0006] Furthermore, in step one, the three-axis scanning method includes: the first rotation axis controls the probe to rotate around the central axis of the branch pipe on the main pipe through a track fixed on the branch pipe, the horizontal axis controls the horizontal displacement of the probe on the main pipe, and the second rotation axis controls the tilt angle of the probe to fit the pipe seat workpiece, and the scanning section is always perpendicular to the weld.

[0007] Furthermore, in step 2, the initial position of the probe is located in the plane where the central axis of the main pipe and the central axis of the branch pipe are located and on the left side of the branch pipe. The rotation angle θ is defined as 0°, and the probe rotates counterclockwise around the central axis of the branch pipe.

[0008] Furthermore, in step 3, the coordinate system transformation matrix from O'x'y'z' to Oxyz is: Get the coordinate transformation equation from O'x'y'z' to Oxyz: in: is the coordinate system transformation matrix from O'x'y'z' to Oxyz; α is the welding angle between the main pipe and the branch pipe.

[0009] Furthermore, in step 3, the solution method for the intersection line equation of the pipe seat fillet weld is: In the coordinate system Oxyz, the outer wall equation of the mother tube satisfies: ; In the coordinate system O'x'y'z', the branch pipe outer wall equation satisfies: ; By combining the coordinate transformation equation from O'x'y'z' to Oxyz, the outer wall equation of the main pipe, and the outer wall equation of the branch pipe, we can obtain the intersection line equation of the pipe seat fillet weld: Where: x∈[-r,r], α∈[0°,180°]; is the outer radius of the mother tube; is the outer diameter of the branch pipe.

[0010] Furthermore, in step 4, the intersection points P and Q of the intersection line of the tube base fillet weld and the ellipse satisfy: Based on the coordinate system transformation equation from Oxyz to O''x''y'', the coordinates of the intersection points P and Q in the coordinate system Oxyz are transformed to the coordinate system O"x"y", and then substituted into the ellipse equation to solve for the major semi-axis a; in: is the probe rotation angle; is the outer diameter of the branch pipe.

[0011] Furthermore, the intersection points P and Q of the pipe seat fillet weld intersection line and the ellipse are the starting endpoint and the ending endpoint of the elliptical arc, respectively, and the starting angle and the ending angle of the elliptical arc are solved through the intersection points P and Q.

[0012] Furthermore, in step 5, obtain any point on the ellipse The slope of the tangent line is: The normal direction is solved based on the tangent slope, and then the reflection direction is determined according to the law of reflection; Where: a is the major axis of the ellipse; b is the minor axis of the ellipse.

[0013] Furthermore, in step five, the intersection points of the sound beam and the elliptical arcs of the main pipe outer wall, the main pipe inner wall, the branch pipe outer wall and the branch pipe inner wall are calculated respectively, and the point closest to the starting point of the sound beam is taken as the intersection point of the sound beam equation and the elliptical equation.

[0014] The present invention also proposes an ultrasonic phased array tube socket corner weld multiple wave detection system, including an ultrasonic phased array instrument and a phased array probe. The ultrasonic phased array instrument is integrated with a processor and a storage medium. The storage medium stores a computer program that can be run on the processor. The processor executes the computer program and implements the ultrasonic phased array tube socket corner weld multiple wave calculation method as described above, so as to output the multiple wave path in real time for defect detection.

[0015] The beneficial effects of the present invention are: The ultrasonic phased array multiple wave calculation method for pipe socket fillet welds of the present invention achieves accurate mapping of pipe socket fillet weld multiple waves during ultrasonic phased array testing by establishing a dual-coordinate system transformation model and geometric equations (intersection line equation, ellipse equation), combined with real-time calculation of the acoustic beam reflection path. The technical effects of the present invention include: (1) Solve the interference of complex structures: To address the industry problem of complex geometric structures of pipe base corner welds and the fact that end corner reflections easily lead to false detection or missed detection, coordinate transformation and intersection line equations are used to accurately describe the spatial morphology of the welds and eliminate structural noise interference; (2) Improve detection efficiency and accuracy: Based on the dynamic calculation of ellipse parameters and sound beam intersection points on the scanned section, it can realize real-time and automatic generation of multiple wave paths without relying on simulation software or manual experience, and without prior simulation. It has the advantages of short calculation time, real-time calculation and low cost, and can effectively improve detection efficiency; (3) Enhanced reliability: The precise reflection direction of the sound beam on the pipe wall is calculated by the reflection law, effectively distinguishing real defects from false signals, and effectively reducing the false detection rate; (4) Strong engineering applicability: The method of the present invention can be integrated into ultrasonic phased array instruments to meet the needs of real-time monitoring and analysis of pipe seat corner weld defects, and can meet the requirements for pipe seat corner weld detection in boiler equipment, nuclear power pipelines, oil pipelines and other fields.

[0016] In summary, the ultrasonic phased array multiple wave calculation method for tube socket fillet welds of the present invention provides a method for accurately plotting multiple waves on the fan-scan diagram of a phased array instrument when inspecting tube socket fillet welds, providing a favorable reference for more accurate analysis of tube socket fillet weld defects. The method of the present invention can greatly improve the efficiency and reliability of tube socket fillet weld inspection, and solve the practical problem that fillet weld inspection in the past has a high reliance on the experience of engineering personnel and is prone to missed detections and false detections. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the purpose, technical solutions and beneficial effects of the present invention more clear, the present invention provides the following drawings for illustration: Figure 1 This is a flow chart of an embodiment of a method for calculating multiple waves of a fillet weld of an ultrasonic phased array tube base according to the present invention; Figure 2 Schematic diagram of the three-axis scanning method; Figure 3 Schematic diagram for parameter definition; Figure 4 is a schematic diagram of the three-dimensional rectangular coordinate systems Oxyz and O'x'y'z'; Figure 5 It is a schematic diagram of the plane rectangular coordinate system O''x''y''; Figure 6 This is the axonometric drawing of the tube seat workpiece; Figure 7 This is a 40° scanning cross-section of the tube seat workpiece; Figure 8 This is a primary wave experimental diagram of the scanning section; Figure 9 This is the multiple wave experimental diagram of the scanning section; Figure 10 This is the primary wave experimental diagram of the 0° scanning section; Figure 11 This is the multiple wave experimental diagram of the 0° scanning section; Figure 12 This is a primary wave experimental diagram of the 40° scanning section; Figure 13 This is the multiple wave experimental diagram of the 40° scanning section; Figure 14 This is a primary wave experimental diagram of a 90° scanning section; Figure 15 This is the multiple wave experimental diagram of the 90° scanning section; Figure 16 This is a primary wave experimental diagram of the 120° scanning section; Figure 17 This is the multiple wave experimental diagram of the 120° scanning section; Figure 18 This is a primary wave experimental diagram of a 180° scanning section; Figure 19 This is the multiple wave experimental diagram of the 180° scanning section. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0019] like Figure 1 As shown, the method for calculating multiple waves of an ultrasonic phased array tube socket fillet weld in this embodiment includes the following steps.

[0020] Step 1: Data collection preparation.

[0021] The scanning gantry uses a three-axis scanning method. The probe is located on the main pipe. The first rotation axis controls the probe's rotation around the central axis of the branch pipe, the horizontal axis controls the probe's distance from the branch pipe's outer surface, and the second rotation axis controls the probe's tilt angle. Data acquisition is performed using an ultrasonic phased array instrument and phased array probe, which supports 3D encoding. This includes the following details.

[0022] (1) Set the scanning mode. In order to obtain the data required for subsequent geometric analysis, it is necessary to perform scanning according to the scanning mode required by this embodiment. Specifically, this embodiment sets the scanning frame to adopt a three-axis scanning mode, and the probe is located on the mother pipe, wherein: the first rotation axis controls the probe to rotate around the central axis of the branch pipe on the mother pipe through the track fixed on the branch pipe; the horizontal axis controls the horizontal displacement of the probe on the mother pipe to control the distance between the probe and the outer surface of the branch pipe; the second rotation axis controls the tilt angle of the probe to correctly fit the pipe seat workpiece. During the scanning process, the scanning section is always perpendicular to the weld (the intersection line of the pipe seat workpiece), such as Figure 2 shown.

[0023] (2) Selection of probes and instruments. This embodiment uses an ultrasonic phased array instrument and a phased array probe for data acquisition. The ultrasonic phased array instrument supports three-dimensional encoding.

[0024] Step 2: Data acquisition and imaging.

[0025] This embodiment uses an ultrasonic phased array instrument and a phased array probe to acquire data and obtain an S-scan image of the current scanned section. Specifically, the cross-sectional scan is performed according to the data acquisition method required in step 1. The probe is initially positioned in the plane containing the central axis of the main pipe and the central axis of the branch pipe, to the left of the branch pipe. At this point, the probe's rotation angle around the central axis of the branch pipe is defined as 0°. The probe rotates counterclockwise around the central axis of the branch pipe to obtain an S-scan image of the current scanned section using the ultrasonic phased array instrument.

[0026] Step 3: Calculate the intersection line equation of the pipe seat fillet weld.

[0027] (1) Define parameters.

[0028] like Figure 3 As shown in the figure, the defined parameters include the main pipe wall thickness H, the main pipe outer radius R, the branch pipe wall thickness h, the branch pipe outer diameter r, the main pipe-branch weld angle α, the probe rotation angle θ, and the distance d between the probe and the branch pipe outer surface. The probe rotation angle θ about the branch pipe centerline is recorded along the scanning axis's rotation axis. When the probe is located in the plane of the main pipe and branch pipe centerlines and on the left side of the branch pipe, θ = 0°, and the probe rotates counterclockwise about the branch pipe centerline. The distance d between the probe and the branch pipe outer surface is recorded along the horizontal axis of the scanning axis.

[0029] (2) Establish a three-dimensional rectangular coordinate system.

[0030] Establish three-dimensional rectangular coordinate systems Oxyz and O'x'y'z', where: Oxyz takes the intersection of the main tube centerline and the branch tube centerline as the origin O, the main tube centerline as the y-axis, and the x-axis perpendicular to the plane where the main tube centerline and the branch tube centerline are located; O'x'y'z' takes the intersection of the main tube centerline and the branch tube centerline as the origin O', the branch tube centerline as the y'axis, and the x'axis perpendicular to the plane where the main tube centerline and the branch tube centerline are located. In this embodiment, the coordinate systems Oxyz and O'x'y'z' are both left-handed coordinate systems, such as Figure 4 shown.

[0031] (3) Calculate the coordinate transformation between the coordinate systems Oxyz and O'x'y'z'.

[0032] O'x'y'z' is essentially Oxyz rotated around the x-axis (180° - α). The coordinate system Oxyz is a left-handed coordinate system and should follow the left-hand rule. That is, when rotating around the x-axis, the left thumb points in the positive direction of the x-axis, and the direction of the other four fingers in the fist is the positive direction of the rotation around the x-axis. Specifically, the transformation matrix for a rotation angle β around the x-axis is: Substituting (180°-α) into β, the transformation matrix of rotating (180°-α) around the x-axis is: The coordinate system transformation matrix from O'x'y'z' to Oxyz is: Therefore, a point (x', y', z') in the coordinate system O'x'y'z' is transformed into a point (x,y,z) in the coordinate system Oxyz, satisfying the equation: From this, we can get the coordinate transformation equation from O'x'y'z' to Oxyz: in: is the coordinate system transformation matrix from O'x'y'z' to Oxyz; α is the welding angle between the main pipe and the branch pipe.

[0033] (4) Calculate the intersection line equation of the pipe seat corner weld.

[0034] In the coordinate system Oxyz, the outer wall equation of the mother tube satisfies: In the coordinate system O'x'y'z', the branch pipe outer wall equation satisfies: By combining the coordinate transformation equation from O'x'y'z' to Oxyz, the outer wall equation of the main pipe, and the outer wall equation of the branch pipe, we can obtain the intersection line equation of the pipe seat fillet weld: Where: x∈[-r,r], α∈[0°,180°]; is the outer radius of the mother tube; is the outer diameter of the branch pipe.

[0035] Step 4: Calculate the ellipse equation of the current scanning section.

[0036] (1) Establish a plane rectangular coordinate system in the current scanning section.

[0037] In the current scanning section, the cross-section of the mother tube is an ellipse (when the cross-section of the mother tube is rectangular, it is relatively simple to skip it, and when the cross-section of the mother tube is circular, it can be treated as a special ellipse). With the center of the ellipse as the coordinate origin O'', the major and minor axes of the ellipse are the x'' axis and y'' axis respectively, and a plane rectangular coordinate system O''x''y'' is established, as shown in the following example: Figure 5 shown.

[0038] (2) Calculate the coordinate transformation between the coordinate systems Oxyz and O''x''y''.

[0039] During the scanning process, the scanning section is always perpendicular to the weld. Therefore, in this embodiment, in the plane rectangular coordinate system O''x''y'' is established in the current scanning section, the y'' axis corresponds to the z axis of Oxyz, and the x'' axis corresponds to the y axis of Oxyz rotated -θ around the z axis and then takes the opposite direction.

[0040] Specifically, the transformation matrix for rotating β around the z-axis is: Therefore, the point (x, y, z) in the coordinate system Oxyz is transformed into the point (x'', y'') in the coordinate system O''x''y''z'', satisfying the equation: From this, we can solve: (3) Calculate the equation of the ellipse and the starting and ending angles of the elliptical arc.

[0041] The ellipse parameters are calculated by transforming the coordinate system from Oxyz to O''x''y''. The ellipse parameters include the major semi-axis a and the minor semi-axis b. The minor semi-axis b is equal to the outer radius R of the mother pipe, and the major semi-axis a is calculated from the intersection of the intersection line of the pipe seat fillet weld and the ellipse.

[0042] The standard equation of an ellipse is: Since the scanning section is always parallel to the z-axis, it can be concluded that the y'' axis radius of the ellipse is equal to the outer wall radius of the mother tube, that is: Take the intersection point P of the intersecting line and the ellipse under the current scanning section, such as Figure 5 As shown, in the coordinate system Oxyz, the x coordinate of point P satisfies Substitute the intersection line equation of the pipe base fillet weld into the equation to obtain the coordinates of point P in the coordinate system Oxyz: Convert the coordinates of point P into a point in the coordinate system O''x''y'': Take another intersection point Q of the intersection line and the ellipse under the current scanning section, such as Figure 5 As shown, the x coordinate of point Q satisfies: The coordinates of point Q in the coordinate system O''x''y'' are obtained using the P point coordinate calculation method.

[0043] Based on the Oxyz to O''x''y'' coordinate system transformation equation, the coordinates of the intersection points P and Q in the Oxyz coordinate system are converted to the O"x"y" coordinate system, and then substituted into the ellipse equation to solve for the major axis a. Where: is the probe rotation angle; is the outer diameter of the branch pipe.

[0044] The intersection points P and Q of the pipe seat fillet weld intersection line and the ellipse are the starting endpoint and the ending endpoint of the ellipse arc, respectively. The starting angle and the ending angle of the ellipse arc are solved through the intersection points P and Q.

[0045] Similarly, the ellipse equations, the starting angles and the ending angles of the ellipse arcs of the inner wall of the main pipe, the outer wall of the branch pipe and the inner wall of the branch pipe under the current scanning section can be calculated.

[0046] Step 5: Calculate the intersection point and reflection direction of the sound beam and the ellipse.

[0047] (1) Calculate the intersection of the sound beam and the ellipse.

[0048] Because calculating an ellipse is complex, it's necessary to first convert the beam's origin and emission direction to the O'x'y' coordinate system. Based on the beam's origin and direction, a linear equation can be derived. Substituting this into the ellipse equation, the intersection of the beam and ellipse equations can be found.

[0049] Intersection points outside the elliptical arc angle are excluded. If there are two intersection points, the one closest to the beam start point is used. The reflection direction is calculated based on the reflection law and used to determine the multiple wave path.

[0050] Calculate the intersection points of the sound beam with the outer wall of the main tube, the inner wall of the main tube, the outer wall of the branch tube, and the inner wall of the branch tube respectively. The point closest to the starting point of the sound beam is the intersection point of the sound beam and the tube seat workpiece.

[0051] (2) Calculate the reflection direction of the sound beam.

[0052] The reflection of the sound beam follows the law of reflection. The incident angle is equal to the reflection angle, and the incident sound beam, the reflected sound beam and the normal are in the same plane. Get any point on the ellipse The slope of the tangent line is: The direction of the normal is determined based on the slope of the tangent line, and the direction of reflection is determined based on the law of reflection. Where: a is the major semi-axis of the ellipse; b is the minor semi-axis of the ellipse.

[0053] Calculate the intersection points of the sound beam with the elliptical arcs of the main pipe outer wall, main pipe inner wall, branch pipe outer wall and branch pipe inner wall respectively, and take the point closest to the starting point of the sound beam as the intersection point of the sound beam equation and the elliptical equation.

[0054] Step 6: Repeat step 5 to calculate multiple waves and output the results for defect analysis.

[0055] This embodiment also proposes an ultrasonic phased array multiple wave detection system for tube socket fillet welds, including an ultrasonic phased array instrument and a phased array probe. The ultrasonic phased array instrument integrates a processor and a storage medium. The storage medium stores a computer program that can be run on the processor. The processor executes the computer program and implements the ultrasonic phased array tube socket fillet weld multiple wave calculation method described above in this embodiment, so as to output the multiple wave path in real time for defect detection.

[0056] The following describes the method for calculating multiple waves of the ultrasonic phased array tube base fillet weld of this embodiment in conjunction with specific experiments.

[0057] Scanning parameters: main pipe outer radius = 254 mm, main pipe thickness = 22.5 mm, branch pipe outer radius = 23 mm, branch pipe thickness = 10 mm, angle between main pipe and branch pipe = 90°, horizontal distance between probe front and branch pipe = 6 mm, scanning results are as follows Figure 10-19 Specifically, Figure 8 As shown in the figure, it is a diagram of a primary wave experiment. Figure 9 The figure shows the multiple wave experiment diagram.

[0058] The above embodiments are merely preferred embodiments for the purpose of fully illustrating the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

Claims

1. A method for calculating multiple waves of an ultrasonic phased array tube base fillet weld, characterized by: The steps include: Step 1: Data Acquisition Preparation: Set up the scanning gantry using a three-axis scanning method. The probe is located on the main pipe. The first rotation axis controls the probe's rotation around the central axis of the branch pipe, the horizontal axis controls the probe's distance from the outer surface of the branch pipe, and the second rotation axis controls the probe's tilt angle. Data acquisition is performed using an ultrasonic phased array instrument and a phased array probe. The ultrasonic phased array instrument supports 3D encoding. Step 2: Data acquisition and imaging: Use ultrasonic phased array instruments and phased array probes to acquire data and obtain S-scan imaging images of the current scan section; Step 3: Calculate the intersection line equation of the pipe seat fillet weld: define the parameters including the main pipe wall thickness H, the main pipe outer radius R, the branch pipe wall thickness h, the branch pipe outer diameter r, the main pipe and branch pipe welding angle α, the probe rotation angle θ and the distance d between the probe and the branch pipe outer surface; establish the three-dimensional rectangular coordinate system Oxyz and O'x'y'z', Where: Oxyz takes the intersection of the centerline of the main pipe and the centerline of the branch pipe as its origin, and the centerline of the main pipe as its y-axis; O'x'y'z' takes the centerline of the branch pipe as its y'-axis. Calculate the coordinate transformation equation from O'x'y'z' to Oxyz, solve the equations for the outer wall of the main pipe and the outer wall of the branch pipe simultaneously, and solve the intersection line equation of the pipe seat fillet weld. Step 4: Calculate the ellipse equation of the current scan section: Establish a plane rectangular coordinate system O''x''y'' on the current scan section, where the y'' axis corresponds to the z-axis of Oxyz, and the x'' axis corresponds to the y-axis of Oxyz rotated -θ around the z-axis and then inverted; calculate the ellipse parameters through the coordinate system transformation from Oxyz to O''x''y''. The ellipse parameters include the major semi-axis a and the minor semi-axis b, where the minor semi-axis b is equal to the outer radius R of the mother pipe, and the major semi-axis a is calculated from the intersection of the pipe seat fillet weld intersection line and the ellipse; Step 5: Calculate the intersection of the sound beam and the ellipse and the reflection direction: Convert the starting point and direction of the sound beam to the coordinate system O''x''y'' and solve the intersection of the sound beam equation and the ellipse equation. Eliminate the intersection points that are not within the ellipse arc angle range and take the intersection point closest to the sound beam starting point. Calculate the reflection direction based on the reflection law to determine the multiple wave path. Step 6: Repeat step 5 to calculate multiple waves and output the results for defect analysis.

2. The method for calculating multiple waves of ultrasonic phased array tube base fillet welds according to claim 1, characterized in that: In step 1, the three-axis scanning method includes: the first rotation axis controls the probe to rotate around the central axis of the branch pipe on the main pipe through a track fixed on the branch pipe, the horizontal axis controls the horizontal displacement of the probe on the main pipe, and the second rotation axis controls the tilt angle of the probe to fit the pipe seat workpiece, and the scanning section is always perpendicular to the weld.

3. The method for calculating multiple waves of ultrasonic phased array tube base fillet welds according to claim 1, characterized in that: In step 2, the initial position of the probe is located in the plane where the central axis of the main pipe and the central axis of the branch pipe are located and on the left side of the branch pipe. The rotation angle θ is defined as 0°, and the probe rotates counterclockwise around the central axis of the branch pipe.

4. The method for calculating multiple waves of ultrasonic phased array tube socket fillet welds according to claim 1, characterized in that: In step 3, the coordinate system transformation matrix from O'x'y'z' to Oxyz is: Get the coordinate transformation equation from O'x'y'z' to Oxyz: in: is the coordinate system transformation matrix from O'x'y'z' to Oxyz; α is the welding angle between the main pipe and the branch pipe.

5. The method for calculating multiple waves of ultrasonic phased array tube base fillet welds according to claim 1, characterized in that: In step 3, the solution method for the intersection line equation of the pipe seat fillet weld is: In the coordinate system Oxyz, the outer wall equation of the mother tube satisfies: ; In the coordinate system O'x'y'z', the equation of the outer wall of the branch pipe satisfies: ; By combining the coordinate transformation equation from O'x'y'z' to Oxyz, the outer wall equation of the main pipe, and the outer wall equation of the branch pipe, we can obtain the intersection line equation of the pipe seat fillet weld: Where: x∈[-r,r], α∈[0°,180°]; is the outer radius of the mother tube; is the outer diameter of the branch pipe.

6. The method for calculating multiple waves of ultrasonic phased array tube base fillet welds according to claim 1, characterized in that: In step 4, the intersection points P and Q of the pipe base fillet weld intersection line and the ellipse satisfy: Based on the coordinate system transformation equation from Oxyz to O''x''y'', the coordinates of the intersection points P and Q in the coordinate system Oxyz are transformed to the coordinate system O"x"y", and then substituted into the ellipse equation to solve for the major semi-axis a; in: is the probe rotation angle; is the outer diameter of the branch pipe.

7. The method for calculating multiple waves of ultrasonic phased array tube base fillet welds according to claim 6, characterized in that: The intersection points P and Q of the pipe seat fillet weld intersection line and the ellipse are the starting endpoint and the ending endpoint of the ellipse arc, respectively. The starting angle and the ending angle of the ellipse arc are solved through the intersection points P and Q.

8. The method for calculating multiple waves of ultrasonic phased array tube base fillet welds according to claim 1, characterized in that: In step 5, obtain any point on the ellipse The slope of the tangent line is: The normal direction is solved based on the tangent slope, and then the reflection direction is determined according to the law of reflection; Where: a is the major semi-axis of the ellipse; b is the minor semi-axis of the ellipse.

9. The method for calculating multiple waves of ultrasonic phased array tube base fillet welds according to claim 1, characterized in that: In step five, the intersection points of the sound beam and the elliptical arcs of the main pipe outer wall, the main pipe inner wall, the branch pipe outer wall and the branch pipe inner wall are calculated respectively, and the point closest to the starting point of the sound beam is taken as the intersection point of the sound beam equation and the elliptical equation.

10. An ultrasonic phased array multiple wave detection system for a tube socket corner weld, comprising an ultrasonic phased array instrument and a phased array probe, wherein the ultrasonic phased array instrument is integrated with a processor and a storage medium, wherein the storage medium stores a computer program that can be run on the processor, and the processor executes the computer program and implements the ultrasonic phased array multiple wave calculation method for a tube socket corner weld as described in any one of items 1-9, so as to output the multiple wave path in real time for defect detection.

Images