Monitoring and strength measuring system for welding cracks

Abstract

The invention discloses a monitoring and strength measuring system for welding cracks, which comprises a monitoring unit, a data processing unit, a strength evaluation unit, a control unit and an output unit, and is characterized in that the monitoring unit is used for acquiring various physical parameters of crack formation and expansion of a welding joint in an operation process; the data processing unit preprocesses and analyzes the received physical parameters to generate crack state monitoring data; the strength evaluation unit dynamically evaluates the residual strength of the welding joint in combination with the mechanical property of the material; the control unit automatically adjusts welding process parameters, such as welding heat input, welding speed and cooling rate, according to crack monitoring data and strength evaluation information; the real-time monitoring and dynamic adjustment in the welding process are achieved by comprehensively monitoring crack propagation and evaluating the structural strength, the service life of a welding structure can be effectively prolonged, and the safety and reliability of the welding structure can be ensured.

Description

Technical Field

[0001] The invention relates to a system for monitoring and measuring the strength of welding cracks. Background Art

[0002] Welding is a widely used connection technology in many industrial fields, especially in machinery manufacturing, shipbuilding, construction, aerospace and other industries. The welding quality has a direct impact on the safety and service life of the structure. However, during the welding process, due to the influence of factors such as materials, process parameters and external environment, cracks may appear inside and outside the weld. The appearance of welding cracks will not only reduce the mechanical properties of the welded joint, but also may cause early failure of the structure, causing serious safety hazards. Therefore, the detection and evaluation of welding cracks are of great significance in welding quality control.

[0003] At present, the commonly used welding crack detection technologies mainly include ultrasonic testing, X-ray testing, magnetic particle testing and visual inspection. Although these detection technologies have achieved certain results in specific scenarios, they still have many shortcomings and cannot meet the requirements of welding quality control for high efficiency, real-time and accuracy. Specific technical problems include:

[0004] Existing welding crack detection methods are mostly post-weld detection, which cannot achieve real-time monitoring during the welding process. This means that the crack may not be discovered until it has expanded to a level that endangers the safety of the structure during the welding process, resulting in the inability to take effective measures for repair or process adjustment in a timely manner, increasing the risk of welding failure.

[0005] Conventional detection methods such as visual inspection and magnetic particle testing mainly target visible cracks on the welding surface and are difficult to effectively detect internal or deep hidden cracks. Although ultrasonic and X-ray testing can detect internal cracks to a certain extent, their accuracy and resolution are limited, especially in complex welded structures. It is easy to miss tiny cracks, reducing the reliability of detection.

[0006] Most existing technologies only focus on the existence of cracks, but fail to fully evaluate the crack morphology, expansion rate and its specific impact on the mechanical strength of the welded joint. There is a lack of quantitative analysis of the relationship between cracks and the residual strength of the weld, which makes it impossible to provide an accurate basis for the strength assessment of the welded joint and the formulation of subsequent repair plans.

[0007] Therefore, a system is needed that can monitor cracks in real time and automatically evaluate their impact on the strength of welded joints, so as to improve the efficiency and accuracy of welding quality control and reduce safety hazards in production. Summary of the invention

[0008] The purpose of the present invention is to solve the above deficiencies in the prior art and provide a system for monitoring and measuring the strength of welding cracks. By accurately monitoring, dynamically analyzing and evaluating the strength of cracks during welding, the system can track the formation and expansion of cracks in real time and adjust welding process parameters based on the evaluation results, thereby solving the problems of inaccurate monitoring of welding cracks, delayed strength evaluation and lack of real-time control in the prior art. The following is a specific solution:

[0009] A system for monitoring and measuring the strength of welding cracks comprises: a monitoring unit, a data processing unit, a strength evaluation unit, a control unit and an output unit, wherein the monitoring unit is used to obtain a variety of physical parameters related to the formation and expansion of cracks in a connecting component during operation, wherein the physical parameters at least include parameters related to the crack formation position, the crack expansion direction and the crack morphology; the data processing unit is connected to the monitoring unit and is used to receive and process the physical parameters to generate monitoring data of the crack state, wherein the data processing unit comprises: a data preprocessing module for preprocessing the physical parameters received from the monitoring unit; a state analysis module for analyzing the state of the crack; and a state analysis module for analyzing the state of the crack. An analysis module is used to analyze and predict the expansion of the crack based on the monitoring data; a strength evaluation unit communicates with the data processing unit and is used to evaluate the strength of the connection component according to the monitoring data of the crack state in combination with the mechanical properties of the material, and generate strength change information related to the crack; the control unit is used to adjust the operating parameters or issue an alarm signal according to the monitoring data of the crack and the strength evaluation information, so as to reduce the impact of the crack on the connection component; the output unit is used to display or output the monitoring results of the crack and the strength evaluation information, or send the information to the remote monitoring device through the communication module.

[0010] Furthermore, the monitoring unit further includes a multi-dimensional sensor array, which is deployed in a three-dimensional space by a matrix arrangement S (x, y, z), defined as:

[0011] Among them, S (x, y, z) represents the sensing point in three-dimensional space, T (i, j, k) represents the spatial coordinates of each sensor node in different axes, and the array is used to obtain the crack growth path and expansion speed data at different spatial positions of the weld; the step of obtaining the monitored physical parameters further includes using a multimodal sensor array to perform all-round detection of the welding area, and the multimodal sensor array generates a multidimensional data matrix by synchronously collecting multiple physical quantities such as thermal stress, vibration strain and electromagnetic radiation. The matrix data is integrated through a complex signal fusion algorithm to provide more accurate crack expansion path and position information.

[0012] Furthermore, the state analysis module establishes a mathematical model of crack propagation based on a finite element analysis algorithm, and the model is defined as: Among them, σ ij represents the stress tensor on the crack surface, x i , x j are the spatial coordinates in two directions on the crack surface, respectively, and f(x, t) is the crack propagation function when the time t changes. The stress distribution of crack propagation is dynamically predicted through this model. The crack propagation prediction model based on the finite element analysis algorithm analyzes the nonlinear propagation behavior of the crack through a multi-layer perceptron architecture, and dynamically adjusts the weights of the nodes in each layer to achieve real-time prediction of crack propagation under complex welding conditions. The prediction results are used to guide subsequent strength evaluation and process parameter adjustment.

[0013] Furthermore, the strength evaluation unit calculates the strain energy U through Poisson's ratio v Young's modulus E based on the crack propagation state and the physical properties of the material, and the formula is:

[0014] Among them, U is the elastic strain energy per unit volume, ε is the strain of the material in the direction of crack propagation. The residual strength of the welded joint is obtained through this calculation, and the influence of the crack on the overall mechanical properties of the welded component is evaluated. The strength evaluation step includes analyzing the microstructural characteristics of the welded joint. The analysis method combines the changes in grain size, orientation and grain boundaries to quantitatively evaluate the local stress concentration phenomenon near the weld, determine the potential threat of crack propagation to the joint strength, and generate a residual strength decay curve over a long period of time.

[0015] Furthermore, the control unit further combines Laplace transform Used to process real-time monitoring data and adjust operating parameters based on the crack growth model, the Laplace transform is defined as: Where f(t) is the time domain function of crack growth, e -st is an attenuation factor, s is a complex domain variable, and the time dependence of the crack is predicted through the transformation and fed back to the control system to optimize the welding process parameters in real time. The operating parameter adjustment step further includes dynamically adjusting the combination of heat input and cooling rate during the welding process based on a feedback control algorithm to ensure that the welding parameters are accurately optimized before the crack propagates to a critical point, thereby avoiding the potential risks caused by accelerated crack propagation. The feedback algorithm includes a composite control strategy of fuzzy control and proportional integral differential control.

[0016] Furthermore, the output unit further analyzes the frequency distribution of the crack signal based on Fourier transform, which is defined as: Among them, ω is the angular frequency, f(t) is the signal of the crack state changing with time, and the crack extension signal in the time domain is converted to the frequency domain through the Fourier transform to analyze the spectral characteristics of crack extension and output the corresponding frequency domain monitoring data. The crack extension and strength assessment results are uploaded to the cloud database in real time through the remote communication module. The data is further processed by the remote analysis system to generate a long-term structural health monitoring report of the welding area, which includes crack extension rate, stress concentration area, potential failure mode and corresponding preventive maintenance suggestions.

[0017] Furthermore, the following method is also included: S1: a step of monitoring physical parameters acquisition, wherein a plurality of physical parameters of crack formation of the welding joint during operation are acquired by a monitoring unit, wherein the physical parameters at least include parameters related to crack formation position, crack extension direction and crack morphology;

[0018] S2: receiving and processing the physical parameters through a data processing unit to generate monitoring data of the crack state;

[0019] S3: The strength evaluation unit evaluates the residual strength of the weld joint based on the monitoring data of the crack state and the mechanical properties of the material to generate strength change information related to the crack;

[0020] S4: an operation parameter adjustment step, wherein the control unit automatically adjusts the welding process parameters according to the crack monitoring data and the strength evaluation information, specifically including adjusting the welding heat input, the welding speed or the cooling rate;

[0021] S5: Display or output the crack monitoring results and strength assessment information through the output unit.

[0022] Furthermore, the receiving and processing of the physical parameters by the data processing unit to generate monitoring data of the crack status includes: S21: preprocessing the physical parameters received from the monitoring unit to eliminate interference from environmental noise and irrelevant signals; S22: dynamically analyzing and predicting the expansion state of the crack based on the preprocessed monitoring data.

[0023] Beneficial effects: The present invention uses a multi-modal sensor array and a variety of detection methods such as acoustic emission, strain gauges, and thermal imaging to more comprehensively and accurately obtain the physical parameters of crack growth, solving the problem that a single monitoring method is limited to a certain type of crack growth.

[0024] Traditional strength assessment methods often evaluate cracks only after they have expanded to a significant degree, which may miss the best repair time. The present invention can provide accurate strength change predictions at the early stage of cracks through real-time data processing and finite element analysis, predict the potential failure risk of welded joints in advance, and avoid crack expansion to the irreversible stage.

[0025] The control unit of the present invention automatically adjusts the welding heat input, welding speed and cooling rate based on real-time monitoring data and strength assessment results, can effectively control the expansion of cracks, improve the intelligence level of the welding process, realize real-time monitoring of welding cracks, strength assessment and automatic control of process parameters, and significantly improves the welding quality and the reliability of the welding joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the system structure of a system for monitoring and strength determination of welding cracks;

[0027] Figure 2 It is a schematic diagram of a measuring method for a monitoring and strength measuring system for welding cracks;

[0028] Figure 3 A further method schematic diagram of S2 for a welding crack monitoring and strength determination system. DETAILED DESCRIPTION

[0029] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with embodiments and drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0030] Please see Figure 1-3 A monitoring and strength determination system for welding cracks includes: a monitoring unit, a data processing unit, a strength evaluation unit, a control unit and an output unit, wherein the monitoring unit is used to obtain a variety of physical parameters related to crack formation and expansion of a connecting component during operation, and the physical parameters at least include parameters related to crack formation position, crack expansion direction and crack morphology; the data processing unit is connected to the monitoring unit, and is used to receive and process the physical parameters and generate monitoring data of the crack state, and the data processing unit includes: a data preprocessing module, which is used to preprocess the physical parameters received from the monitoring unit; a state analysis module, which is used to analyze and predict the expansion of the crack based on the monitoring data; a strength evaluation unit, which communicates with the data processing unit, and is used to evaluate the strength of the connecting component according to the monitoring data of the crack state and the mechanical properties of the material, and generate strength change information related to the crack; the control unit is used to adjust the operating parameters or issue an alarm signal according to the crack monitoring data and strength evaluation information to reduce the impact of the crack on the connecting component; the output unit is used to display or output the crack monitoring results and strength evaluation information or send the information to a remote monitoring device through a communication module.

[0031] The monitoring unit further includes a multi-dimensional sensor array, which is deployed in a three-dimensional space through a matrix arrangement S (x, y, z), defined as: Among them, S (x, y, z) represents the sensing point in three-dimensional space, T (i, j, k) represents the spatial coordinates of each sensor node in different axes, and the array is used to obtain the crack growth path and expansion speed data at different spatial positions of the weld.

[0032] The state analysis module establishes a mathematical model of crack propagation based on the finite element analysis algorithm. The model is defined as: Among them, σ ij represents the stress tensor on the crack surface, x i , x j are the spatial coordinates of the two directions on the crack surface, respectively. f(x, t) is the crack extension function when the time t changes. The model is used to dynamically predict the stress distribution of crack extension.

[0033] The strength evaluation unit calculates the strain energy U through Poisson's ratio v Young's modulus E based on the crack propagation state and the physical properties of the material. The formula is: Among them, U is the elastic strain energy per unit volume, and ε is the strain of the material in the direction of crack propagation. The residual strength of the welded joint is obtained through this calculation, and the influence of the crack on the overall mechanical properties of the welded component is evaluated.

[0034] The control unit further combines the Laplace transform Used to process real-time monitoring data and adjust operating parameters based on the crack growth model, the Laplace transform is defined as:

[0035] Where f(t) is the time domain function of crack growth, e -st is the attenuation factor, s is a complex domain variable, and the time dependence of the crack is predicted through transformation and fed back to the control system to optimize the welding process parameters in real time.

[0036] The output unit further analyzes the frequency distribution of the crack signal based on Fourier transform, which is defined as:

[0037] Among them, ω is the angular frequency, f(t) is the signal of the crack state changing with time, and the crack extension signal in the time domain is converted to the frequency domain through the Fourier transform to analyze the spectral characteristics of crack extension and output the corresponding frequency domain monitoring data.

[0038] The method also includes the following: S1: a step of monitoring physical parameters for obtaining, through a monitoring unit, obtaining a variety of physical parameters of crack formation in a welding joint during operation, the physical parameters at least including parameters related to crack formation position, crack extension direction and crack morphology;

[0039] S2: receiving and processing physical parameters through a data processing unit to generate monitoring data of crack status;

[0040] S3: The strength evaluation unit evaluates the residual strength of the weld joint based on the monitoring data of the crack state and the mechanical properties of the material to generate strength change information related to the crack;

[0041] S4: an operation parameter adjustment step, wherein the control unit automatically adjusts the welding process parameters according to the crack monitoring data and the strength evaluation information, specifically including adjusting the welding heat input, the welding speed or the cooling rate;

[0042] S5: Display or output the crack monitoring results and strength assessment information through the output unit.

[0043] Receiving and processing physical parameters through a data processing unit to generate monitoring data of the crack state includes: S21: preprocessing the physical parameters received from the monitoring unit to eliminate interference from environmental noise and irrelevant signals; S22: dynamically analyzing and predicting the expansion state of the crack based on the preprocessed monitoring data.

[0044] For the purpose of greater clarity, the invention is described in detail through the following examples.

[0045] In a specific embodiment, the monitoring unit is mainly composed of the following sensors, which are used to obtain various physical parameters related to crack formation and expansion of the welding joint during operation: Acoustic emission sensor: A wide-band acoustic emission sensor of model AE-SX2040 is used, with a frequency response range of 50kHz-400kHz and a sensitivity of 90dB, which is suitable for capturing the acoustic wave signal when tiny cracks are formed. The sensors are installed at key positions of the welding joint with an interval of about 10cm to ensure that the monitoring covers all possible crack formation areas;

[0046] Strain gauge sensor: Use high-precision strain gauge model SGD-7 / 350-LY11, with a rated resistance of 350Ω, a maximum strain of ±2%, and high temperature resistance, with an upper temperature limit of 300°C, suitable for stress and strain monitoring in welding environments. The strain gauges are arranged in the predetermined area of ​​the welding joint, and each sensor is 5cm apart;

[0047] Infrared thermal imager: The model is FLIR A400 series, with a temperature measurement range of -40°C to +500°C and a spatial resolution of 640x 480 pixels. The thermal imager is used to monitor the temperature changes caused by thermal stress during the welding process in real time, and can accurately capture the local temperature anomalies accompanying the crack formation process.

[0048] In a specific embodiment, the control unit adjusts the welding process parameters in real time based on the crack monitoring data and the strength assessment results. The specific control method is as follows: the welding current and voltage are controlled by a numerical control system with an accuracy of ±1A. For example, when it is detected that the crack propagation speed exceeds a threshold value, such as 0.1mm / s, the system automatically reduces the welding current from 180A to 160A, thereby reducing the welding heat input and delaying the crack propagation; the system controls the welding speed through a servo motor with an adjustment range of 0.5-2.5mm / s. The specific adjustment depends on the real-time status of the welding joint. For example, when it is assessed that the crack propagation speed is higher than the safety value, the system will automatically reduce the welding speed to 0.8mm / s; the cooling system adopts high-precision liquid cooling equipment, and the cooling water flow control range is 0.1-1.5L / min. When the crack propagation speed is faster, the system automatically increases the cooling water flow, thereby accelerating the cooling rate of the welding joint, reducing thermal stress, and inhibiting the expansion of the crack.

[0049] In a specific embodiment, the output unit is responsible for displaying and outputting crack monitoring results and strength assessment information, including: the display screen adopts a 10.1-inch industrial-grade touch screen with a resolution of 1280x 800, which displays crack extension conditions, residual strength assessment results and system alarm information in real time; the communication module is a 5G communication module, model QuectelRM500Q, with a transmission rate of up to 1.6Gbps, which is used to send monitoring data and assessment results to a remote monitoring center in real time, facilitating remote monitoring and adjustment of the welding process.

[0050] The system can be widely used in crack monitoring and strength assessment of important welded structures such as high-pressure pipelines, ship structures and bridges. For example, during the maintenance of a high-pressure transmission pipeline, the system is installed at the welded joints of the pipeline to monitor the crack propagation in real time, and the welding process parameters are adjusted according to the assessment results to extend the service life of the pipeline. Through these specific equipment and parameters, the welding crack monitoring and strength measurement system of the present invention can accurately and real-timely realize the monitoring, analysis, strength assessment and dynamic adjustment of welding process of welding cracks, thereby ensuring the safety and reliability of the welded structure.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A system for monitoring and measuring the strength of welding cracks, characterized in that: include: A monitoring unit, a data processing unit, a strength evaluation unit, a control unit and an output unit, wherein the monitoring unit is used to obtain a variety of physical parameters related to crack formation and expansion of the connection component during operation, wherein the physical parameters at least include parameters related to crack formation position, crack expansion direction and crack morphology; The data processing unit is connected to the monitoring unit, and is used to receive and process the physical parameters to generate monitoring data of the crack state. The data processing unit includes: a data preprocessing module, which is used to preprocess the physical parameters received from the monitoring unit; a state analysis module, which is used to analyze and predict the expansion of the crack based on the monitoring data; a strength evaluation unit, which communicates with the data processing unit, and is used to evaluate the strength of the connecting component based on the monitoring data of the crack state and the mechanical properties of the material, and generate strength change information related to the crack; the control unit is used to adjust the operating parameters or issue an alarm signal according to the crack monitoring data and strength evaluation information to reduce the impact of the crack on the connecting component; the output unit is used to display or output the crack monitoring results and strength evaluation information or send the information to the remote monitoring device through the communication module.

2. A system for monitoring and measuring welding cracks according to claim 1, characterized in that ,The monitoring unit further includes a multi-dimensional sensor array, which is deployed in a three-dimensional space by a matrix arrangement S(x, y, z), defined as: Among them, S (x, y, z) represents the sensing point in three-dimensional space, T (i, j, k) represents the spatial coordinates of each sensor node in different axes, and the array is used to obtain crack growth path and expansion speed data at different spatial positions of the weld.

3. A system for monitoring and measuring welding cracks according to claim 1, characterized in that: The state analysis module establishes a mathematical model of crack propagation based on the finite element analysis algorithm. The model is defined as: Among them, σ ij represents the stress tensor on the crack surface, x i , x j are the spatial coordinates of the two directions on the crack surface, respectively. f(x, t) is the crack extension function when the time t changes. The model is used to dynamically predict the stress distribution of crack extension.

4. A system for monitoring and measuring welding cracks according to claim 1, characterized in that: The strength evaluation unit calculates the strain energy U through Poisson's ratio v Young's modulus E based on the crack propagation state and the physical properties of the material, and the formula is: Among them, U is the elastic strain energy per unit volume, and ε is the strain of the material in the direction of crack propagation. The residual strength of the welded joint is obtained through this calculation, and the influence of the crack on the overall mechanical properties of the welded component is evaluated.

5. A system for monitoring and measuring welding cracks according to claims 1-4, characterized in that: The control unit further combines the Laplace transform Used to process real-time monitoring data and adjust operating parameters based on the crack growth model, the Laplace transform is defined as: Where f(t) is the time domain function of crack growth, e -st is the attenuation factor, s is a complex domain variable, and the time dependence of the crack is predicted through the transformation and fed back to the control system to optimize the welding process parameters in real time.

6. A system for monitoring and measuring the strength of welding cracks according to claim 5, characterized in that: The output unit further analyzes the frequency distribution of the crack signal based on Fourier transform, which is defined as: Among them, ω is the angular frequency, f(t) is the signal of the crack state changing with time, and the crack extension signal in the time domain is converted to the frequency domain through the Fourier transform to analyze the spectral characteristics of crack extension and output the corresponding frequency domain monitoring data.

7. A welding crack monitoring and strength measurement system according to claim 1, characterized in that: The method also includes the following: S1: a step of monitoring the acquisition of physical parameters, wherein a monitoring unit is used to acquire a variety of physical parameters of crack formation in a welding joint during operation, wherein the physical parameters at least include parameters related to crack formation position, crack extension direction, and crack morphology; S2: receiving and processing the physical parameters through a data processing unit to generate monitoring data of the crack state; S3: The strength evaluation unit evaluates the residual strength of the weld joint based on the monitoring data of the crack state and the mechanical properties of the material to generate strength change information related to the crack; S4: an operation parameter adjustment step, wherein the control unit automatically adjusts the welding process parameters according to the crack monitoring data and the strength evaluation information, specifically including adjusting the welding heat input, the welding speed or the cooling rate; S5: Display or output the crack monitoring results and strength assessment information through the output unit.

8. A system for monitoring and measuring the strength of welding cracks according to claim 7, characterized in that: The step of receiving and processing the physical parameters by a data processing unit to generate monitoring data of the crack state includes: S21: preprocessing the physical parameters received from the monitoring unit to eliminate interference from environmental noise and irrelevant signals; S22: dynamically analyzing and predicting the expansion state of the crack based on the preprocessed monitoring data.

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