A system for monitoring and measuring the strength of weld cracks

Abstract

This invention discloses a system for monitoring and determining the strength of welded cracks, comprising a monitoring unit, a data processing unit, a strength assessment unit, a control unit, and an output unit. The monitoring unit acquires various physical parameters related to crack formation and propagation during the welding process. The data processing unit preprocesses and analyzes the received physical parameters to generate crack state monitoring data. The strength assessment unit dynamically assesses the remaining strength of the welded joint based on the mechanical properties of the material. The control unit automatically adjusts welding process parameters, such as welding heat input, welding speed, and cooling rate, according to the crack monitoring data and strength assessment information. The output unit displays or outputs the monitoring results and assessment information. This invention achieves real-time monitoring and dynamic adjustment during the welding process by comprehensively monitoring crack propagation and assessing structural strength, effectively extending the service life of welded structures and ensuring their safety and reliability.

Description

Technical Field

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

[0002] Welding is a widely used joining technology in many industrial fields, especially in machinery manufacturing, shipbuilding, construction, and aerospace. Welding quality has a direct impact on the safety and service life of structures. However, during the welding process, due to factors such as materials, process parameters, and the external environment, cracks may occur inside and outside the weld. The appearance of welding cracks not only reduces the mechanical properties of the welded joint but may also lead to premature structural failure, causing serious safety hazards. Therefore, the detection and assessment of welding cracks are of great significance in welding quality control.

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

[0004] Existing methods for detecting welding cracks are mostly post-weld inspections, which cannot achieve real-time monitoring during the welding process. This means that cracks may only be discovered after they have expanded to a level that endangers structural safety during the welding process, making it impossible to take timely and effective measures for repair or process adjustment, thus increasing the risk of welding failure.

[0005] Conventional testing methods such as visual inspection and magnetic particle testing are mainly for visible cracks on the weld 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, where they are prone to missing tiny cracks, reducing the reliability of the testing.

[0006] Most existing technologies only focus on the presence or absence of cracks, but fail to fully assess the crack morphology, propagation rate and its specific impact on the mechanical strength of welded joints. They also lack quantitative analysis of the relationship between cracks and the remaining strength of welds, which makes it impossible to provide accurate basis for strength assessment of welded joints and the formulation of subsequent repair plans.

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

[0008] The purpose of this invention is to overcome the shortcomings of 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 the welding process, this system can track the formation and propagation of cracks in real time and adjust welding process parameters based on the evaluation results. This solves the problems of insufficient accuracy in monitoring welding cracks, delayed strength evaluation, and lack of real-time control in the prior art. The specific solution is as follows:

[0009] A system for monitoring and determining the strength of weld cracks includes: a monitoring unit, a data processing unit, a strength assessment unit, a control unit, and an output unit. The monitoring unit acquires various physical parameters related to crack formation and propagation in the connected components during operation. These physical parameters include at least those related to crack formation location, crack propagation direction, and crack morphology. The data processing unit, connected to the monitoring unit, receives and processes the physical parameters to generate monitoring data on the crack state. The data processing unit includes: a data preprocessing module for preprocessing the physical parameters received from the monitoring unit; and a state classification module. The system includes an analysis module for analyzing and predicting crack propagation based on the monitoring data; a strength assessment unit, communicating with the data processing unit, for assessing the strength of the connecting component based on the monitoring data of the crack state and the mechanical properties of the material, and generating strength change information related to the crack; a control unit for adjusting operating parameters or issuing alarm signals based on the crack monitoring data and strength assessment information to reduce the impact of the crack on the connecting component; and an output unit for displaying or outputting the crack monitoring results and strength assessment information, or sending the information to a remote monitoring device via the communication module.

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

[0011] Wherein, S(x, y, z) represents the sensing point in three-dimensional space, and T(i, j, k) represents the spatial coordinates of each sensor node in different axes. The array is used to acquire crack growth path and propagation speed data at different spatial locations of the weld. The step of acquiring the monitored physical parameters further includes using a multimodal sensor array to perform omnidirectional detection of the weld area. The multimodal sensor array generates a multidimensional data matrix by synchronously acquiring 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 propagation path and location information.

[0012] Furthermore, the state analysis module establishes a mathematical model of crack propagation based on the finite element analysis algorithm. The model is defined as follows: Where, σ ij The stress tensor on the crack surface, x i x j Here, x and t represent the spatial coordinates in two directions on the crack surface, respectively, and f(x, t) is the crack propagation function as time t changes. This model dynamically predicts the stress distribution during crack propagation. Based on a finite element analysis algorithm, the crack propagation prediction model analyzes the nonlinear propagation behavior of the crack using a multilayer perceptron architecture, dynamically adjusting the weights of each node to achieve real-time prediction of crack propagation under complex welding conditions. The prediction results are used to guide subsequent strength assessment and process parameter adjustment.

[0013] Furthermore, the strength assessment unit calculates the strain energy U based on the crack propagation state and the material's physical properties, using Poisson's ratio v and Young's modulus E, as shown in the formula:

[0014] Where U is the elastic strain energy per unit volume and ε is the strain of the material in the crack propagation direction, the residual strength of the welded joint is calculated, and the impact of crack on the overall mechanical properties of the welded component is evaluated. The strength evaluation step includes analyzing the microstructure 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 incorporates the Laplace transform. Used to process real-time monitoring data and adjust operating parameters based on the crack propagation model, the Laplace transform is defined as follows: Where f(t) is the time-domain function of crack growth, e -st The attenuation factor is s, and s is a complex domain variable. The time dependence of the crack is predicted by the transformation and fed back to the control system to optimize the welding process parameters in real time. The operation parameter adjustment step further includes dynamically adjusting the combination of heat input and cooling rate during the welding process based on the feedback control algorithm to ensure that the welding parameters are accurately optimized before the crack propagates to the critical point, so as to avoid the potential risks caused by the accelerated crack propagation. The feedback algorithm includes a composite control strategy of fuzzy control and proportional-integral-derivative control.

[0016] Furthermore, the output unit further analyzes the frequency distribution of the crack signal based on Fourier transform, and defines it as: Where ω is the angular frequency and f(t) is the signal of crack state changing with time. The crack propagation signal in the time domain is converted to the frequency domain through this Fourier transform to analyze the spectral characteristics of crack propagation and output the corresponding frequency domain monitoring data. The crack propagation 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 welded area. The report includes crack propagation rate, stress concentration area, potential failure mode and corresponding preventive maintenance recommendations.

[0017] Furthermore, it also includes the following method: S1: the step of acquiring physical parameters by monitoring the acquisition of various physical parameters of crack formation in the welded joint during operation through the monitoring unit, wherein the physical parameters include at least the relevant parameters of crack formation location, crack propagation direction and crack morphology;

[0018] S2: The data processing unit receives and processes the physical parameters to generate monitoring data on the crack state;

[0019] S3: Based on the monitoring data of the crack state and combined with the mechanical properties of the material, the strength assessment unit evaluates the remaining strength of the welded joint and generates strength change information related to the crack.

[0020] S4: Operation parameter adjustment steps. The control unit automatically adjusts the welding process parameters based on crack monitoring data and strength assessment information, specifically including adjusting the welding heat input, welding speed, or cooling rate.

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

[0022] Furthermore, the step of receiving and processing the physical parameters through the 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 crack propagation state based on the preprocessed monitoring data.

[0023] Beneficial effects: This invention uses a multi-modal sensor array to comprehensively apply various detection methods such as acoustic emission, strain gauges, and thermal imaging, which can obtain physical parameters of crack propagation more comprehensively and accurately, and solve the problem that a single monitoring method is limited to the propagation of a certain type of crack.

[0024] Traditional strength assessment methods often only assess the crack after it has expanded to a significant extent, which may cause the best time for repair to be missed. This invention, through real-time data processing and finite element analysis, can provide accurate prediction of strength changes in the early stage of cracking, predict the potential failure risk of welded joints in advance, and prevent cracks from expanding to an irreversible stage.

[0025] The control unit of this invention automatically adjusts the welding heat input, welding speed and cooling rate based on real-time monitoring data and strength assessment results, which can effectively control the propagation 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 improve welding quality and the reliability of welded joints. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a system structure for monitoring and measuring the strength of welding cracks.

[0027] Figure 2 This is a schematic diagram of a measurement method for a system for monitoring and determining the strength of welding cracks;

[0028] Figure 3 This is a schematic diagram of a further method of S2, a system for monitoring and determining the strength of weld cracks. Detailed Implementation

[0029] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments and accompanying drawings. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0030] Please refer to Figure 1-3 A system for monitoring and determining the strength of weld cracks includes: a monitoring unit, a data processing unit, a strength assessment unit, a control unit, and an output unit. The monitoring unit acquires various physical parameters related to crack formation and propagation in the connected components during operation. These physical parameters include at least those related to crack formation location, crack propagation direction, and crack morphology. The data processing unit, connected to the monitoring unit, receives and processes the physical parameters to generate monitoring data on the crack state. The data processing unit includes: a data preprocessing module for preprocessing the physical parameters received from the monitoring unit; a state analysis module for analyzing and predicting crack propagation based on the monitoring data; a strength assessment unit, communicating with the data processing unit, for assessing the strength of the connected components based on the crack state monitoring data and material mechanical properties, and generating crack-related strength change information; a control unit for adjusting operating parameters or issuing alarm signals based on the crack monitoring data and strength assessment information to reduce the impact of cracks on the connected components; and an output unit for displaying or outputting the crack monitoring results and strength assessment information, or sending the information to a remote monitoring device via a communication module.

[0031] The monitoring unit further includes a multi-dimensional sensor array, which is deployed in three-dimensional space in a matrix arrangement S(x, y, z), defined as: Where 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 acquire crack growth path and propagation speed data at different spatial locations of the weld.

[0032] The state analysis module, based on the finite element analysis algorithm, establishes a mathematical model for crack propagation. The model is defined as follows: Where, σ ij The stress tensor on the crack surface, x i x j Let f(x, t) be the spatial coordinates of two directions on the crack surface, and f(x, t) be the crack propagation function as time t changes. This model is used to dynamically predict the stress distribution of crack propagation.

[0033] The strength assessment unit calculates the strain energy U based on the crack propagation state and the material's physical properties, using Poisson's ratio (v) and Young's modulus (E). The formula is as follows: Where U is the elastic strain energy per unit volume and ε is the strain of the material in the crack propagation direction, the residual strength of the welded joint is calculated using this method, and the impact of the crack on the overall mechanical properties of the welded component is evaluated.

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

[0035] Where f(t) is the time-domain function of crack growth, e -st The attenuation factor is s, and the complex domain variable is s. The time dependence of the crack is predicted by 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, and defines it as:

[0037] Where ω is the angular frequency and f(t) is the signal of crack state changing with time. The crack propagation signal in the time domain is converted to the frequency domain through this Fourier transform in order to analyze the spectral characteristics of crack propagation and output the corresponding frequency domain monitoring data.

[0038] It also includes the following method: S1: the step of acquiring physical parameters, which acquires various physical parameters of crack formation in the welded joint during operation through the monitoring unit. The physical parameters include at least the relevant parameters of crack formation location, crack propagation direction and crack morphology.

[0039] S2: The data processing unit receives and processes physical parameters to generate monitoring data on the crack state;

[0040] S3: Based on the monitoring data of the crack state and combined with the mechanical properties of the material, the strength assessment unit evaluates the remaining strength of the welded joint and generates strength change information related to the crack.

[0041] S4: Operation parameter adjustment steps. The control unit automatically adjusts the welding process parameters based on crack monitoring data and strength assessment information, specifically including adjusting the welding heat input, welding speed, or cooling rate.

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

[0043] The data processing unit receives and processes physical parameters to generate monitoring data on crack state, including: 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 crack propagation state based on the preprocessed monitoring data.

[0044] For clarity, the following examples will be used to provide a detailed description.

[0045] In a specific embodiment, the monitoring unit mainly consists of the following sensors, which are used to acquire various physical parameters related to crack formation and propagation in the welded joint during operation: Acoustic emission sensor: A wideband acoustic emission sensor of model AE-SX2040 is used, with a frequency response range of 50kHz-400kHz and a sensitivity of 90dB. It is suitable for capturing the acoustic signal when a small crack forms. The sensor is installed at a critical position on the welded joint, with an interval of about 10cm, to ensure that the monitoring covers all possible crack formation areas.

[0046] Strain gauge sensor: Uses high-precision strain gauges of 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℃. Suitable for stress and strain monitoring in welding environments. The strain gauges are arranged in a predetermined area of ​​the welding joint, with each sensor 5cm apart.

[0047] Infrared thermal imager: Model FLIR A400 series, with a temperature measurement range of -40℃ to +500°C and a spatial resolution of 640x480 pixels. The thermal imager is used to monitor temperature changes caused by thermal stress during the welding process in real time and can accurately capture local temperature anomalies that accompany crack formation.

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

[0049] In one specific embodiment, the output unit is responsible for displaying and outputting crack monitoring results and strength assessment information. Specifically, it includes: a 10.1-inch industrial-grade touchscreen with a resolution of 1280x800, which displays crack propagation, remaining strength assessment results, and system alarm information in real time; and a 5G communication module, model QuectelRM500Q, with a transmission rate of up to 1.6Gbps, 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] This system can be widely used for 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, this system can be installed at the welded joints of the pipeline to monitor the crack propagation in real time. The welding process parameters can be adjusted based on the assessment results to extend the service life of the pipeline. Through these specific devices and parameters, the welding crack monitoring and strength assessment system of this invention can accurately and in real time monitor, analyze, assess the strength of welding cracks, and dynamically adjust the welding process to ensure 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 solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A system for monitoring and determining the strength of weld cracks, characterized in that, include: The system includes a monitoring unit, a data processing unit, a strength assessment unit, a control unit, and an output unit. The monitoring unit is used to acquire various physical parameters related to crack formation and propagation of the connected components during operation. These physical parameters include at least parameters related to crack formation location, crack propagation 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 on the crack state. The data processing unit includes: a data preprocessing module for preprocessing the physical parameters received from the monitoring unit; a state analysis module for analyzing and predicting the crack propagation based on the monitoring data; and a strength assessment unit, communicating with the data processing unit, for assessing the strength of the connecting component based on the crack state monitoring data and material mechanical properties, and generating strength change information related to the crack. The control unit is used to adjust the operating parameters or issue an alarm signal based on the crack monitoring data and strength assessment 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 assessment information or send the information to a remote monitoring device via the communication module. The monitoring unit further includes a multi-dimensional sensor array, which is arranged in a matrix in three-dimensional space. Deployment is defined as: ,in, Represents a sensing point in three-dimensional space. The array represents the spatial coordinates of each sensor node along different axes and is used to acquire data on crack growth paths and propagation speeds at different spatial locations of the weld. The state analysis module, based on the finite element analysis algorithm, establishes a mathematical model for crack propagation, which is defined as follows: ,in, This represents the stress tensor on the crack surface. , These are the spatial coordinates of two directions on the crack surface. The crack propagation function is defined as the crack propagation time t changes. This model is used to dynamically predict the stress distribution during crack propagation. The strength assessment unit calculates the strain energy U based on the crack propagation state and the material's physical properties, using Poisson's ratio v and Young's modulus E, as shown in the formula: Where U is the elastic strain energy per unit volume, The residual strength of the welded joint is calculated based on the strain of the material in the crack propagation direction, and the impact of the crack on the overall mechanical properties of the welded component is evaluated. The control unit further incorporates Laplace transform. Used to process real-time monitoring data and adjust operating parameters based on the crack propagation model, the Laplace transform is defined as follows: ,in, Let be the time-domain function of crack growth. The attenuation factor is s, and the complex domain variable is s. The time dependence of the crack is predicted by the transformation and fed back to the control system to optimize the welding process parameters in real time.

2. The system for monitoring and determining the strength of welding cracks according to claim 1, characterized in that, The output unit further analyzes the frequency distribution of the crack signal based on Fourier transform, and defines it as follows: ,in, Angular frequency, The signal represents the change of crack state over time. This Fourier transform converts the crack propagation signal in the time domain to the frequency domain, allowing for the analysis of the spectral characteristics of crack propagation and the output of corresponding frequency domain monitoring data.

3. The system for monitoring and determining the strength of welding cracks according to claim 1, characterized in that, It also includes the following method: S1: the step of acquiring physical parameters by monitoring, acquiring various physical parameters of crack formation in the welded joint during operation through the monitoring unit, the physical parameters including at least the relevant parameters of crack formation location, crack propagation direction and crack morphology; S2: The data processing unit receives and processes the physical parameters to generate monitoring data on the crack state; S3: Based on the monitoring data of the crack state and combined with the mechanical properties of the material, the strength assessment unit evaluates the remaining strength of the welded joint and generates strength change information related to the crack. S4: Operation parameter adjustment steps. The control unit automatically adjusts the welding process parameters based on crack monitoring data and strength assessment information, specifically including adjusting the welding heat input, welding speed, or cooling rate. S5: Display or output crack monitoring results and strength assessment information through the output unit.

4. The system for monitoring and determining the strength of welding cracks according to claim 3, characterized in that, The step of receiving and processing the physical parameters through the 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 crack propagation state based on the preprocessed monitoring data.

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