Method for inverting pipeline material parameters by using ultrasonic guided waves

Abstract

The invention discloses a method for inverting pipeline material parameters by using ultrasonic guided waves, relates to the technical field of special equipment detection, and can obtain the pipeline material parameters in a lossless manner by performing signal processing on ultrasonic signals obtained from an ultrasonic array transducer. The method for inverting the pipeline material parameters by using the ultrasonic guided waves comprises the following steps: S1, arranging a circumferential ultrasonic transducer array on the surface of a pipeline, and obtaining ultrasonic guided wave array data; s2, processing the array waveform data, and extracting ultrasonic guided wave frequency dispersion data; s3, setting initial model parameters of the pipeline; s4, calculating theoretical frequency dispersion data of the pipeline according to the model parameters; s5, constructing a target function according to the theoretical frequency dispersion data and the actually measured and extracted ultrasonic guided wave frequency dispersion data; s6, updating model parameters by adopting a mode search algorithm; and S7, judging whether the current model parameter updating frequency reaches the maximum iteration frequency, if so, ending, and otherwise, returning to the step S4.

Description

Technical Field

[0001] The invention relates to the technical field of special equipment detection, and in particular to a method for inverting pipeline material parameters by using ultrasonic guided waves. Background Art

[0002] At present, with the continuous development of industrial facilities and the increasing complexity of pipeline systems, the safety and reliability of pressure pipelines have become an important concern. During long-term use, pipeline materials may change due to factors such as corrosion, fatigue, and wear, affecting the mechanical properties and operational safety of the pipeline. Therefore, how to efficiently and accurately evaluate the damage status of the pipeline has become a key issue that needs to be solved in the field of pipeline inspection.

[0003] Ultrasonic thickness measurement is an essential stage in the pipeline inspection process, but the premise of this method is to know the material sound velocity of the current pipeline. In some cases, the material of the pipeline may be unknown, which requires some material analysis methods to obtain the current material parameters of the pipeline.

[0004] Traditional pipeline material analysis methods, such as sampling analysis, metallographic testing, and X-ray imaging, usually require downtime, disassembly, or destruction of the pipeline, which can easily have a significant impact on production and operation and maintenance, and these methods have certain limitations in detecting the uniformity of materials inside and outside the pipeline. Ultrasonic guided wave testing, as a non-destructive testing method, has attracted widespread attention because it can evaluate the internal structure and material properties of the workpiece without destroying it. However, different modes of guided waves have different dispersion characteristics, which makes guided wave testing difficult in the actual inspection process. Summary of the invention

[0005] The purpose of the present invention is to provide a method for inverting pipeline material parameters using ultrasonic guided waves, which can non-destructively obtain the material parameters of the pipeline by processing the ultrasonic signal obtained on the ultrasonic array transducer, and provide more reliable technical support for the safe monitoring and maintenance of the pipeline.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme: A method for inverting pipeline material parameters using ultrasonic guided waves comprises the following steps: Step S1, arranging a circumferential ultrasonic transducer array on the surface of the pipeline to obtain ultrasonic guided wave array data; Step S2, processing array waveform data and extracting ultrasonic guided wave dispersion data; Step S3, setting initial model parameters of the pipeline; Step S4, calculating pipeline theoretical dispersion data according to model parameters; Step S5, constructing an objective function based on theoretical dispersion data and ultrasonic guided wave dispersion data extracted from actual measurements; Step S6: Update model parameters using a pattern search algorithm; Step S7, determine whether the current model parameter update times reaches the maximum number of iterations, if so, end, otherwise return to step S4.

[0007] In actual application, the step S1 is specifically as follows: An annular ultrasonic transducer array is arranged along the circumference of the pipeline, and ultrasonic guided wave array data is collected in a one-transmit-multiple-receive manner; The process of acquiring array ultrasonic guided wave data is as follows: the signal excitation module excites the ultrasonic transducer to emit an ultrasonic signal; the array data received by the receiving transducer is received and stored by the data acquisition module; the data received by the data acquisition module is connected to a computer for data post-processing.

[0008] Wherein, the step S2 is specifically as follows: The matrix beam method is used to process the ultrasonic guided wave array data to obtain the pipeline circumferential guided wave dispersion data.

[0009] Specifically, the step S3 is as follows: Setting the initial model parameters of the pipeline, mainly including presetting the known pipeline density, pipeline inner diameter, pipeline outer diameter, and the initial value of the Lame constant of the pipeline to be inverted and its parameter range; Set the inversion model parameters, mainly including the maximum number of iterations and iteration accuracy.

[0010] Furthermore, the step S4 is specifically as follows: Calculate the theoretical dispersion data of the pipeline based on the model parameters; specifically, solve the dispersion equation that satisfies the following Phase velocity value: ; in, represents the angular frequency, represents the phase velocity dispersion data to be solved, represents the Lame constant of the pipeline, represents the pipeline density, Indicates the inner and outer diameters of the pipe.

[0011] Furthermore, the step S5 is specifically as follows: Assume that the value of the pipeline circumferential wave dispersion data extracted in step S2 is , the theoretically calculated dispersion data in step S4 is , then the objective function : .

[0012] Furthermore, the step S6 is specifically as follows: Update model parameters using pattern search algorithm .

[0013] Compared with the prior art, the method of inverting pipeline material parameters using ultrasonic guided waves described in the present invention has the following advantages: In the method for inverting pipeline material parameters using ultrasonic guided waves provided by the present invention, ultrasonic guided wave array data is obtained by arranging a circumferential ultrasonic transducer array on the pipeline surface; array waveform data is processed to extract ultrasonic guided wave dispersion data; initial model parameters of the pipeline are set; theoretical dispersion data of the pipeline is calculated according to the model parameters; an objective function is constructed according to the theoretical dispersion data and ultrasonic guided wave dispersion data extracted by actual measurement; the model parameters are updated by using a pattern search algorithm; it is judged whether the number of current model parameter updates reaches a maximum number of iterations, if it is greater, the method ends, otherwise it returns to "calculating the theoretical dispersion data of the pipeline according to the model parameters"; therefore, the method for inverting pipeline material parameters using ultrasonic guided waves provided by the present invention uses ultrasonic guided waves to invert the material parameters of the pressure pipeline, and there is no need to disassemble or destroy the pipeline itself during the detection process; at the same time, it can realize a multi-parameter inversion method, which can not only invert the material parameters of isotropic materials, but also invert the material parameters of anisotropic materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic flow chart of a method for inverting pipeline material parameters using ultrasonic guided waves provided in an embodiment of the present invention; Figure 2 A schematic diagram of ultrasonic array waveform data simulated by finite element in a method for inverting pipeline material parameters using ultrasonic guided waves provided in an embodiment of the present invention; Figure 3 A schematic diagram of dispersion data of waveform data simulated by finite element in a method for inverting pipeline material parameters using ultrasonic guided waves provided in an embodiment of the present invention; Figure 4 A trend graph showing how the mean square error varies with the number of iterations when a pattern search algorithm is used to invert material parameters in a method for inverting pipeline material parameters using ultrasonic guided waves provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0015] For ease of understanding, the method for inverting pipeline material parameters using ultrasonic guided waves provided by an embodiment of the present invention is described in detail below in conjunction with the accompanying drawings.

[0016] The embodiment of the present invention provides a method for inverting pipeline material parameters using ultrasonic guided waves, such as Figure 1-Figure 4 As shown, the following steps are included: Step S1, arranging a circumferential ultrasonic transducer array on the surface of the pipeline to obtain ultrasonic guided wave array data; Step S2, processing array waveform data and extracting ultrasonic guided wave dispersion data; Step S3, setting initial model parameters of the pipeline; Step S4, calculating pipeline theoretical dispersion data according to model parameters; Step S5, constructing an objective function based on theoretical dispersion data and ultrasonic guided wave dispersion data extracted from actual measurements; Step S6: Update model parameters using a pattern search algorithm; Step S7, determine whether the current model parameter update times reaches the maximum number of iterations, if so, end, otherwise return to step S4.

[0017] Compared with the prior art, the method for inverting pipeline material parameters using ultrasonic guided waves described in the embodiment of the present invention has the following advantages: In the method for inverting pipeline material parameters using ultrasonic guided waves provided by an embodiment of the present invention, since a circumferential ultrasonic transducer array is arranged on the pipeline surface, ultrasonic guided wave array data is obtained; array waveform data is processed to extract ultrasonic guided wave dispersion data; initial model parameters of the pipeline are set; theoretical dispersion data of the pipeline is calculated according to the model parameters; an objective function is constructed according to the theoretical dispersion data and ultrasonic guided wave dispersion data extracted by actual measurement; the model parameters are updated using a pattern search algorithm; it is determined whether the current number of model parameter updates reaches a maximum number of iterations, if so, the method ends, otherwise it returns to "calculating the theoretical dispersion data of the pipeline according to the model parameters"; therefore, the method for inverting pipeline material parameters using ultrasonic guided waves provided by an embodiment of the present invention uses ultrasonic guided waves to invert the material parameters of the pressure pipeline, and there is no need to disassemble or destroy the pipeline itself during the detection process; at the same time, it can realize a multi-parameter inversion method, which can not only invert the material parameters of isotropic materials, but also invert the material parameters of anisotropic materials.

[0018] In practical application, the above step S1 may specifically be: An annular ultrasonic transducer array is arranged along the circumference of the pipeline, and ultrasonic guided wave array data is collected in a one-transmit-multiple-receive manner; The process of acquiring array ultrasonic guided wave data is as follows: the signal excitation module excites the ultrasonic transducer to emit an ultrasonic signal; the array data received by the receiving transducer is received and stored by the data acquisition module; the data received by the data acquisition module is connected to a computer for data post-processing.

[0019] The above step S2 may specifically be: The modified matrix pencil method is used to process the ultrasonic guided wave array data to obtain the pipeline circumferential guided wave dispersion data.

[0020] Specifically, the above step S3 may be: Setting the initial model parameters of the pipeline, mainly including presetting the known pipeline density, pipeline inner diameter, pipeline outer diameter, and the initial value of the Lame constant of the pipeline to be inverted and its parameter range; Set the inversion model parameters, mainly including the maximum number of iterations and iteration accuracy.

[0021] Furthermore, the above step S4 may specifically be: Calculate the theoretical dispersion data of the pipeline based on the model parameters; specifically, solve the dispersion equation that satisfies the following Phase velocity value: ; in, represents the angular frequency, represents the phase velocity dispersion data to be solved, represents the Lame constant of the pipeline, represents the pipeline density, Indicates the inner and outer diameters of the pipe.

[0022] Furthermore, the above step S5 may specifically be: Assume that the value of the pipeline circumferential wave dispersion data extracted in step S2 is , the theoretically calculated dispersion data in step S4 is , then the objective function : .

[0023] Furthermore, the above step S6 may specifically be: Update model parameters using pattern search (PS) algorithm .

[0024] The method is a quasi-direct search method for solving global optimization problems with simple bound constraints. Specific embodiment one: Firstly, a circumferential ultrasonic transducer array is arranged on the surface of the pipeline, and the circumferential ultrasonic guided wave array data is obtained by adopting a one-transmit-multiple-receive method. In this numerical simulation, a velocity source with a linear frequency modulation signal of 10-100kHz is applied along the radial direction of the pipeline, and the following data are obtained: Figure 2 A total of 31 channels of ultrasonic guided wave data are shown; Extraction using matrix bundle method Figure 2 The array waveform data in the Figure 3 The real phase velocity dispersion data shown as solid line; Set the initial pipeline model parameters as shown in Table 1; set the pipeline density to 7800kg / m 3, the inner diameter of the pipeline is 0.1m, and the outer diameter of the pipeline is 0.11m; the initial value of the first Lamé constant is preset to be 100-150Gpa, and the initial value of the second Lamé constant is preset to be 50-100Gpa; the maximum number of iterations is set to 30 times, and the iteration accuracy is set to 1×10 -5 ; The objective function is the second norm of the residual calculated from the theoretical dispersion data obtained by the initial model parameters and the dispersion data extracted by the matrix bundle method; The material parameters of the pipeline are inverted using the pattern search algorithm. The mean square error between the actual dispersion data and the theoretically fitted dispersion data changes with the number of iterations as shown in the figure. Figure 4 As shown; the dispersion data obtained by calculating the material parameters obtained by the final iteration is as follows Figure 3 As shown by the dotted line, it is in good agreement with the actual dispersion data, which illustrates the feasibility of this method.

[0026] Table 1 lists the inversion values ​​of material parameters obtained by this method and their relative errors. From the results, the error is within 5%, which basically meets the actual needs.

[0027] Table 1 True values, inverted values ​​and relative errors of material parameters The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for inverting pipeline material parameters using ultrasonic guided waves, characterized in that: The following steps are involved: Step S1, arranging a circumferential ultrasonic transducer array on the surface of the pipeline to obtain ultrasonic guided wave array data; Step S2, processing array waveform data and extracting ultrasonic guided wave dispersion data; Step S3, setting initial model parameters of the pipeline; Step S4, calculating pipeline theoretical dispersion data according to model parameters; Step S5, constructing an objective function based on theoretical dispersion data and ultrasonic guided wave dispersion data extracted from actual measurements; Step S6: Update model parameters using a pattern search algorithm; Step S7, determine whether the current model parameter update times reaches the maximum number of iterations, if so, end, otherwise return to step S4.

2. The method for inverting pipeline material parameters using ultrasonic guided waves according to claim 1, characterized in that: The step S1 is specifically as follows: An annular ultrasonic transducer array is arranged along the circumference of the pipeline, and ultrasonic guided wave array data is collected in a one-transmit-multiple-receive manner; The process of acquiring array ultrasonic guided wave data is as follows: the signal excitation module excites the ultrasonic transducer to emit an ultrasonic signal; the array data received by the receiving transducer is received and stored by the data acquisition module; the data received by the data acquisition module is connected to a computer for data post-processing.

3. The method for inverting pipeline material parameters using ultrasonic guided waves according to claim 1, characterized in that: The step S2 is specifically as follows: The matrix beam method is used to process the ultrasonic guided wave array data to obtain the pipeline circumferential guided wave dispersion data.

4. The method for inverting pipeline material parameters using ultrasonic guided waves according to claim 1, characterized in that: The step S3 is specifically as follows: Setting the initial model parameters of the pipeline, mainly including presetting the known pipeline density, pipeline inner diameter, pipeline outer diameter, and the initial value of the Lame constant of the pipeline to be inverted and its parameter range; Set the inversion model parameters, mainly including the maximum number of iterations and iteration accuracy.

5. The method for inverting pipeline material parameters using ultrasonic guided waves according to claim 1, characterized in that: The step S4 is specifically as follows: Calculate the theoretical dispersion data of the pipeline based on the model parameters; specifically, solve the dispersion equation that satisfies the following Phase velocity value: ; in, represents the angular frequency, represents the phase velocity dispersion data to be solved, represents the Lame constant of the pipeline, represents the pipeline density, Indicates the inner and outer diameters of the pipe.

6. The method for inverting pipeline material parameters using ultrasonic guided waves according to claim 1, characterized in that: The step S5 is specifically as follows: Assume that the value of the pipeline circumferential wave dispersion data extracted in step S2 is , the theoretically calculated dispersion data in step S4 is , then the objective function : .

7. The method for inverting pipeline material parameters using ultrasonic guided waves according to claim 1, characterized in that: The step S6 is specifically as follows: Update model parameters using pattern search algorithm .

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