Steel structure engineering quality nondestructive testing method

Abstract

The invention discloses a steel structure engineering quality nondestructive testing method, and relates to the technical field of nondestructive testing, and the method comprises the following steps: preparation before detection, ultrasonic wave propagation velocity V calculation according to steel structure attributes, couplant smearing, detection operation, placing an ultrasonic probe on the surface of a steel structure, moving along a predetermined scanning path, and determining the ultrasonic wave propagation velocity V according to the ultrasonic wave propagation velocity V; and data analysis: calculating the defect depth S of the steel structure according to the ultrasonic propagation velocity V and the time difference T3, calculating a quality evaluation index Q according to multiple factors, and performing subsequent work, so that the defect depth S of the steel structure is calculated by combining the time difference T3 with the actual propagation velocity V2, and the defect depth of the steel structure can be accurately judged. The quality evaluation index Q is calculated by comprehensively considering a plurality of factors, so that potential defects can be found in time and repair measures can be taken in time on the premise of not damaging the steel structure, the nondestructive testing quality is improved, and potential safety hazards are avoided.

Description

Technical Field

[0001] The invention relates to the technical field of nondestructive testing, and in particular to a nondestructive testing method for steel structure engineering quality. Background Art

[0002] With the development of modern society and industry, related enterprises attach more and more importance to the quality and safety of construction products, and put forward higher and higher requirements. Under the guidance of relevant national policies, the construction industry has entered a new development height. Steel structure is an important building material in modern construction engineering. Steel structure has many advantages and has become a hot building material in modern construction. Non-destructive testing is to detect the surface and internal structure of the test piece by physical or chemical methods without destroying the test piece, with the help of advanced scientific equipment.

[0003] In order to ensure the safety and reliability of steel structure materials and not affect the performance of the object being tested, corresponding non-destructive testing methods need to be adopted. At present, traditional methods such as visual inspection and magnetic particle inspection have certain effects, but the detection effect is poor. Visual inspection relies on the experience of the inspectors and cannot effectively detect internal defects; although magnetic particle inspection is sensitive to surface defects, it is only applicable to magnetic materials and cannot accurately judge the depth of defects, thus affecting the quality of non-destructive testing and increasing the safety risks of steel structure projects. Summary of the invention

[0004] The purpose of the present invention is to provide a nondestructive testing method for steel structure engineering quality, which solves the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for nondestructive testing of steel structure engineering quality, comprising the following steps:

[0006] Preparation before testing: determine the test object and scope, understand the design requirements, materials and properties of the steel structure. The properties of the steel structure include elastic modulus E, density P and Poisson's ratio B. Calculate the ultrasonic propagation velocity V according to the properties of the steel structure, prepare ultrasonic testing instruments and probes, remove oil, rust and coating impurities on the surface of the steel structure, and grind and polish the surface of the steel structure;

[0007] Apply coupling agent. Select the coupling agent according to the inspection requirements and the properties of the steel structure to be inspected. Then shake the coupling agent container and use a sponge to evenly apply a layer of coupling agent on the surface of the steel structure. Then immediately place the ultrasonic probe on the surface of the steel structure to ensure that the coupling agent is evenly distributed between the ultrasonic probe and the steel structure to form a liquid layer.

[0008] During the inspection, the ultrasonic probe is placed on the surface of the steel structure and moved along the predetermined scanning path. When the ultrasonic wave propagates in the steel structure, it encounters defects and generates reflected waves, which are received by the ultrasonic probe and converted into electrical signals. The inspection instrument amplifies and processes the electrical signals and displays them on the screen. The transmission time T1 and reception time T2 of the ultrasonic wave are recorded, and the time difference T3 from the transmission to the reception of the ultrasonic wave is calculated.

[0009] Data analysis: Analyze the detected data to determine the type and location of steel structure defects, calculate the steel structure defect depth S based on the ultrasonic propagation velocity V and the time difference T3, and calculate the quality assessment index Q based on the data analysis results and multiple factors to compare the quality differences of steel under different conditions;

[0010] For follow-up work, a non-destructive testing report for steel structures is generated based on the test data. Problems found during the test are processed and repaired. At the same time, regular tracking monitoring and re-inspection are carried out to ensure the long-term and stable use of the steel structure project.

[0011] Optionally, the ultrasonic wave propagation velocity V in the pre-detection preparation step includes a theoretical propagation velocity V1 and an actual propagation velocity V2, wherein the calculation formula of the theoretical propagation velocity V1 is:

[0012]

[0013] Where V1 is the theoretical propagation speed;

[0014] E is the elastic modulus, P is the density, and B is the Poisson’s ratio;

[0015] The actual propagation speed V2 is calculated as:

[0016] V2=V1*[1+α*(D1-D2)]

[0017] Where V2 is the actual propagation speed;

[0018] D1 is the actual measured temperature, and D2 is the reference temperature;

[0019] α is the temperature correction coefficient, which is a constant;

[0020] The propagation speed of ultrasound in the medium will be affected by temperature. By adjusting the propagation speed according to the temperature, the actual situation can be reflected more accurately, the location and size of the defect can be determined, the detection accuracy can be improved, and the detection effect can be optimized.

[0021] Optionally, the calculation formula of the time difference T3 in the detection operation step is:

[0022] T3=T2-T1

[0023] Where T3 is the time difference, T2 is the receiving time, and T1 is the transmitting time;

[0024] The calculation formula for the steel structure defect depth S in the data analysis step is:

[0025]

[0026] Where S is the depth of steel structure defects;

[0027] W1 is the weight of the actual propagation speed and time difference;

[0028] W2 is the weight of temperature change;

[0029] J is the value of the probe angle and position change;

[0030] W3 is the weight of the probe angle and position change;

[0031] By calculating the defect depth S of the steel structure, the quality and safety of the steel structure can be quantitatively evaluated. The defect depth information provides a basis for subsequent repair work. Repair personnel can choose appropriate repair methods and materials according to the size and location of the defect depth to ensure the repair effect.

[0032] Optionally, the elastic modulus E is divided by the density P to obtain the steel structure strength The calculation formula of the quality assessment index Q in the data analysis step is:

[0033]

[0034] Where M1 is the strength of the steel structure The weight of

[0035] M2 is the weight of the inverse of Poisson’s ratio B;

[0036] M3 is the weight of the actual propagation speed V2;

[0037] M4 is the weight of the steel structure defect depth S;

[0038] Z is the acoustic impedance, which indicates the impedance of the steel structure to the propagation of sound waves. The calculation formula of the acoustic impedance Z is:

[0039] Z=P*V2

[0040] Where P is the density and V2 is the actual propagation speed;

[0041] The data obtained through non-destructive testing methods, combined with the calculation formula of the quality assessment index Q, can timely identify potential defects in steel without destroying the steel structure, take timely repair measures, and avoid potential safety hazards. The quality assessment index Q is a numerical indicator that can intuitively reflect the overall quality level of the steel structure, making the quality comparison between steel structures from different batches and sources clearer.

[0042] Optionally, in the pre-test preparation step, compressed air is used to spray sand or other abrasives onto the surface of the steel structure to remove rust through impact and friction, chemicals are used to remove oil from the steel structure surface, and high-pressure water guns are used to remove coating impurities.

[0043] Optionally, the ultrasonic testing instrument in the pre-test preparation step is an ultrasonic flaw detector, which uses the propagation mode, reflection and transmission characteristics of ultrasonic waves in materials to detect defects, deformations and cracks inside the material.

[0044] Optionally, in the detection operation step, a plurality of servo motors are used to form a multi-degree-of-freedom scanning system for driving the ultrasonic probe and the steel structure to move along a predetermined trajectory, and the scanning system includes a computer and a data collector.

[0045] Optionally, in the subsequent work steps, the non-destructive testing report includes the project name, structural location, testing method, test results and result judgment. The non-destructive testing report can truly reflect the testing situation and provide clear information for implementing steel structure repair and maintenance work.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The present invention can more accurately reflect the actual situation and improve the accuracy of nondestructive testing by calculating the actual propagation velocity V2 of the ultrasonic wave. The time difference T3 is calculated by the emission time T1 and the receiving time T2, and the defect depth S of the steel structure is calculated in combination with the actual propagation velocity V2, so that the position and size of the defect are more accurate, the internal defects of the steel structure are effectively detected, and a basis is provided for subsequent repair work. By comprehensively considering multiple factors and adding the weight of each influencing factor, the weight of each factor can be adjusted according to the actual situation, so that the evaluation result is more in line with the actual demand. The actual propagation velocity V2 is the basis for calculating the defect depth S of the steel structure. At the same time, the propagation velocity V2 is also a factor of the quality evaluation index Q, which affects the value of the quality evaluation index Q. The quality evaluation index Q comprehensively considers multiple factors, including the actual propagation velocity V2, the defect depth S of the steel structure, etc., and quantitatively evaluates the quality of the steel structure. The above calculation formulas are interconnected and mutually influential, and together constitute the key to the nondestructive testing of steel structure engineering, so as to achieve a comprehensive and accurate evaluation of the quality of the steel structure, improve the quality of the nondestructive testing of the steel structure, and reduce the safety hazards of the steel structure engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] For example, see Figure 1 This embodiment provides a nondestructive testing method for steel structure engineering quality, comprising the following steps:

[0051] Determine the inspection object and scope, understand the design requirements, materials and properties of the steel structure. The properties of the steel structure include elastic modulus E, density P and Poisson's ratio B. Calculate the ultrasonic propagation velocity V according to the properties of the steel structure, prepare ultrasonic inspection instruments and probes, remove oil, rust and coating impurities on the surface of the steel structure, ensure that the surface of the inspection area is clean and flat, and polish the surface of the steel structure;

[0052] Select the coupling agent according to the inspection requirements and the properties of the steel structure to be inspected, then shake the coupling agent container and use a sponge to evenly apply a layer of coupling agent on the surface of the steel structure. Then immediately place the ultrasonic probe on the surface of the steel structure to ensure that the coupling agent is evenly distributed between the ultrasonic probe and the steel structure to form a liquid layer.

[0053] Place the ultrasonic probe on the surface of the steel structure and move it along the predetermined scanning path. When the ultrasonic wave propagates in the steel structure, it encounters defects and generates reflected waves, which are received by the ultrasonic probe and converted into electrical signals. The detection instrument amplifies and processes the electrical signals and displays them on the screen. The ultrasonic wave emission time T1 and reception time T2 are recorded, and the time difference T3 from the emission to the reception of the ultrasonic wave is calculated.

[0054] Analyze the detected data to determine the type and location of steel structure defects, calculate the steel structure defect depth S based on the ultrasonic propagation velocity V and the time difference T3, judge the quality of the steel structure based on the data analysis results, and calculate the quality assessment index Q based on multiple factors to compare the quality differences of steel under different conditions;

[0055] Generate a nondestructive testing report for steel structures based on the test data, and handle and repair problems found during the test to ensure the quality and safety of the steel structure project. At the same time, conduct regular follow-up monitoring and re-inspection to ensure the long-term and stable use of the steel structure project.

[0056] More specifically, in this embodiment: before nondestructive testing of the steel structure, the ultrasonic propagation velocity V is calculated by understanding the design requirements, materials and properties of the steel structure in detail, so as to provide accurate data support for subsequent ultrasonic testing. At the same time, the surface of the steel structure is polished and cleaned of impurities such as oil stains to ensure that the surface of the detection area is clean and flat, and the detection accuracy is improved. The coupling agent is evenly applied to reduce the energy loss in the ultrasonic propagation process and improve the detection sensitivity. The time difference T3 is calculated by the transmission time T1 and the receiving time T2, and the steel structure defect depth S is calculated in combination with the actual propagation velocity V2. The depth of the steel structure defect can be accurately judged, which provides a more reliable basis for subsequent repair work. The quality assessment index Q is calculated by comprehensively considering multiple factors. The quality assessment index Q not only reflects the overall quality level of the steel structure, but also can intuitively compare the quality differences between steel structures of different batches and sources. Potential defects can be discovered in time without destroying the steel structure, and repair measures can be taken in time, thereby improving the quality of nondestructive testing and avoiding potential safety hazards.

[0057] Furthermore, the ultrasonic wave propagation velocity V in the pre-detection preparation step includes a theoretical propagation velocity V1 and an actual propagation velocity V2, wherein the calculation formula of the theoretical propagation velocity V1 is:

[0058]

[0059] Where V1 is the theoretical propagation speed;

[0060] E is the elastic modulus, P is the density, and B is the Poisson’s ratio;

[0061] The actual propagation speed V2 is calculated as:

[0062] V2=V1*[1+α*(D1-D2)]

[0063] Where V2 is the actual propagation speed;

[0064] D1 is the actual measured temperature, and D2 is the reference temperature;

[0065] α is the temperature correction coefficient, which is a constant.

[0066] Furthermore, since the propagation speed of ultrasound in the medium will be affected by temperature, if the influence of temperature is not taken into account and the theoretical propagation speed is directly used for calculation, large errors may result. By adjusting the propagation speed according to the temperature, the actual situation can be reflected more accurately, thereby improving the accuracy of detection. The temperature may be different in different working environments and conditions. By adjusting the ultrasonic propagation speed according to the temperature, the ultrasonic detection instrument can adapt to different working environments and conditions, and the versatility and reliability of the equipment can be improved. In ultrasonic detection, a large amount of data needs to be calculated. If the theoretical propagation speed is used directly for calculation, additional data processing steps may be required to correct the influence of temperature. By adjusting the propagation speed according to the temperature, the actual propagation speed can be directly obtained, reducing the data processing steps and improving the efficiency of non-destructive detection of steel structure projects.

[0067] Furthermore, the calculation formula of the time difference T3 in the detection operation step is:

[0068] T3=T2-T1

[0069] Where T3 is the time difference, T2 is the receiving time, and T1 is the transmitting time;

[0070] The calculation formula for the steel structure defect depth S in the data analysis step is:

[0071]

[0072] Where S is the depth of steel structure defects;

[0073] W1 is the weight of the actual propagation speed and time difference;

[0074] W2 is the weight of temperature change;

[0075] J is the value of the probe angle and position change;

[0076] W3 is the weight of the probe angle and position change.

[0077] Specifically, by calculating the time difference T3, combined with influencing factors such as the actual propagation speed V2, temperature changes, and changes in the probe angle position, the steel structure defect depth S is calculated, making the location and size of the defect more accurate, providing a basis for subsequent repair work. Repair personnel can choose appropriate repair methods and materials according to the size and location of the defect depth to ensure the repair effect, and can determine whether the steel meets the use requirements based on the steel structure defect depth S to avoid safety accidents caused by quality problems.

[0078] Furthermore, the elastic modulus E is divided by the density P to obtain the strength of the steel structure: The calculation formula of the quality assessment index Q in the data analysis step is:

[0079]

[0080] Where M1 is the strength of the steel structure The weight of

[0081] M2 is the weight of the reciprocal of Poisson's ratio B. Since Poisson's ratio B itself is a relatively small number, usually between 0 and 0.5, taking its reciprocal can make this parameter play a more significant role in the quality assessment index Q. This weight determines the contribution of the material deformation difficulty to the quality assessment index Q.

[0082] M3 is the weight of the actual propagation velocity V2, which reflects the speed of ultrasonic wave propagation in steel, and indirectly reflects the uniformity and defects of the internal structure of steel;

[0083] M4 is the weight of the steel structure defect depth S. Deeper defects usually have a more serious impact on the performance of steel. This weight determines the negative impact of the steel structure defect depth S on the quality assessment index Q.

[0084] The above weights are used to adjust the relative importance of each factor in the quality assessment index Q. If you pay more attention to the strength of the steel structure during nondestructive testing, you can set the M1 value to a larger value. If you pay more attention to the internal defects of the steel structure, you can set the M4 value to a larger value. The weight values ​​of each influencing factor can be determined according to the specific application scenario and requirements.

[0085] Z is the acoustic impedance, which indicates the impedance of the steel structure to the propagation of sound waves. The calculation formula of the acoustic impedance Z is:

[0086] Z=P*V2

[0087] Where P is the density and V2 is the actual propagation speed.

[0088] Acoustic impedance Z is an important physical quantity that allows workers to understand the steel structure's ability to absorb and reflect sound waves. In ultrasonic testing, differences in acoustic impedance can be used to distinguish different materials or defects.

[0089] Specifically, the data obtained through non-destructive testing methods, combined with the calculation formula of the quality assessment index Q, can timely identify potential defects in steel without destroying the steel structure, take timely repair measures, and avoid potential safety hazards. The quality assessment index Q contains multiple factors related to non-destructive testing of steel structures, such as elastic modulus E, density P, Poisson's ratio B, actual propagation velocity V2, and steel structure defect depth S, which makes the evaluation results of steel structure projects more comprehensive. The quality assessment index Q is a numerical indicator that can intuitively reflect the overall quality level of steel structures, making the quality comparison between steel structures of different batches and sources clearer, improving the quality of non-destructive testing, and eliminating safety hazards in steel structure projects.

[0090] The value range of the quality assessment index Q is between 10 and 100. The quality assessment index Q will affect the temperature correction coefficient α. The specific relationship formula is:

[0091] Quality evaluation index Q = 50α

[0092] When the quality assessment index Q is 50, α is 1, and no temperature correction is performed. When the quality assessment index Q is 80, α is 1.6. The α value increases with the increase of the quality assessment index Q, and decreases otherwise. By setting the quality assessment index Q to be associated with the α value, the influence of temperature on the ultrasonic propagation velocity can be dynamically adjusted according to the quality assessment index Q and the quality of ultrasonic detection, so as to compensate for errors by performing temperature correction according to the detection data and further improve the detection quality.

[0093] For example 2, please refer to Figure 1 On the basis of the above-mentioned embodiment, in the preparation step before detection, compressed air is used to spray sand or other abrasives onto the surface of the steel structure, rust is removed by impact and friction, chemical agents are used to remove oil stains from the surface of the steel structure, and high-pressure water guns are used to remove coating impurities.

[0094] Specifically, impurities such as oil, rust and coating will hinder the propagation of ultrasound in steel structures, causing ultrasound to be reflected, scattered or absorbed at the interface, thereby weakening the signal strength of the ultrasound. These impurities may also cause the propagation path of the ultrasound to deviate, making the test results inaccurate. Removing these impurities can ensure that ultrasound can be accurately transmitted into the steel structure and improve the accuracy of non-destructive testing.

[0095] In ultrasonic testing, coupling agent is used to fill the tiny gap between the ultrasonic probe and the surface of the steel structure to ensure that the ultrasonic wave can be effectively transmitted from the probe to the steel structure. If there are impurities such as oil, rust or coating on the surface of the steel structure, it will prevent the coupling agent from forming a uniform liquid layer between the probe and the steel structure, thereby reducing the coupling effect. Removing these impurities can ensure that the coupling agent forms a uniform liquid layer between the probe and the steel structure, thereby enhancing the coupling effect and further improving the detection accuracy.

[0096] Furthermore, the ultrasonic testing instrument in the pre-test preparation step is an ultrasonic flaw detector.

[0097] Specifically, the ultrasonic flaw detector uses the propagation mode, reflection and transmission characteristics of ultrasonic waves in materials to detect defects, deformations, cracks and other defect information inside the material. It has the characteristics of non-destructive testing and can detect hidden defects inside steel structures.

[0098] Furthermore, in the detection operation step, a plurality of servo motors are used to form a multi-degree-of-freedom scanning system for driving the ultrasonic probe and the steel structure to move along a predetermined trajectory, and the scanning system includes a computer and a data collector.

[0099] Specifically, according to the preset scanning trajectory, the position of the probe or steel structure is accurately controlled by multiple servo motors, and the probe maintains an appropriate coupling distance with the surface of the steel structure to ensure that the ultrasonic wave can be effectively transmitted. The received ultrasonic signal is sampled and digitized by using a computer and a data acquisition device, and the ultrasonic signal is emitted, received, and sampled at a certain interval to ensure full coverage of the entire scanning area.

[0100] Furthermore, in the subsequent work steps, the non-destructive testing report includes the project name, structural location, testing method, test results and result judgment. The non-destructive testing report can truly reflect the testing situation and provide clear information for implementing steel structure repair and maintenance work.

[0101] Specifically, the non-destructive testing report contains a detailed description and analysis of all aspects of the inspected object, such as material properties, structural characteristics, defects, etc., which can help staff fully understand the quality status of the inspected object and facilitate the formulation of targeted repair and maintenance plans.

[0102] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A nondestructive testing method for steel structure engineering quality, characterized in that: The following steps are involved: Step S1: Preparation before testing, determine the test object and scope, understand the properties of the steel structure, including elastic modulus E, density P and Poisson's ratio B, calculate the ultrasonic propagation velocity V according to the properties of the steel structure, prepare ultrasonic testing instruments and probes, remove oil, rust and coating impurities on the surface of the steel structure, and grind and polish the surface of the steel structure; Step S2: Apply coupling agent. Select coupling agent according to the detection requirements and the properties of the steel structure to be detected. Use a sponge to evenly apply a layer of coupling agent on the surface of the steel structure. Then immediately place the ultrasonic probe on the surface of the steel structure to ensure that the coupling agent is evenly distributed between the ultrasonic probe and the steel structure to form a liquid layer. Step S3: detection operation, placing the ultrasonic probe on the surface of the steel structure and moving it along the predetermined scanning path. When the ultrasonic wave propagates in the steel structure, it encounters defects and generates reflected waves, which are received by the ultrasonic probe and converted into electrical signals. The detection instrument amplifies and processes the electrical signals and displays them on the screen. The emission time T1 and reception time T2 of the ultrasonic wave are recorded, and the time difference T3 from the emission to the reception of the ultrasonic wave is calculated. Step S4: Data analysis, determining the type and location of steel structure defects, calculating the steel structure defect depth S according to the ultrasonic propagation velocity V and the time difference T3, and calculating the quality assessment index Q, which is used to compare the quality differences of steel under different conditions; Step S5: Follow-up work: generate a nondestructive testing report for the steel structure based on the test data, handle and repair the problems found in the test, and conduct regular follow-up monitoring and re-inspection.

2. The nondestructive testing method for steel structure engineering quality according to claim 1 is characterized in that: The ultrasonic wave propagation velocity V in the pre-detection preparation step includes a theoretical propagation velocity V1 and an actual propagation velocity V2, wherein the calculation formula of the theoretical propagation velocity V1 is: Where V1 is the theoretical propagation speed; E is the elastic modulus, P is the density, and B is the Poisson’s ratio; The actual propagation speed V2 is calculated as: V2=V1*[1+α*(D1-D2)] Where V2 is the actual propagation speed; D1 is the actual measured temperature, and D2 is the reference temperature; α is the temperature correction coefficient, which is a constant; The propagation speed of ultrasonic waves in the medium is affected by temperature. By adjusting the propagation speed according to the temperature, the location and size of the defect can be determined.

3. The nondestructive testing method for steel structure engineering quality according to claim 2 is characterized in that: The calculation formula of the time difference T3 from the emission to the reception of the ultrasonic wave in the detection operation step is: T3 = T2 - T1; Where T3 is the time difference, T2 is the receiving time, and T1 is the transmitting time; The calculation formula for the steel structure defect depth S in the data analysis step is: Where S is the depth of steel structure defects; W1 is the weight of the actual propagation speed and time difference; W2 is the weight of temperature change; J is the value of the probe angle and position change; W3 is the weight of the probe angle and position change; By calculating the defect depth S of the steel structure, the quality and safety of the steel structure can be quantitatively evaluated.

4. The nondestructive testing method for steel structure engineering quality according to claim 3 is characterized in that: The elastic modulus E is divided by the density P to obtain the strength of the steel structure. The calculation formula of the quality assessment index Q in the data analysis step is: M1 is the strength of the steel structure The weight of M2 is the weight of the inverse of Poisson’s ratio B; M3 is the weight of the actual propagation speed V2; M4 is the weight of the steel structure defect depth S; Z is the acoustic impedance, which indicates the impedance of the steel structure to the propagation of sound waves. The calculation formula of the acoustic impedance Z is: Z=P*V2 Where P is the density and V2 is the actual propagation speed; The steel structure defect depth S is combined with the quality assessment index Q calculation formula. The quality assessment index Q is a numerical indicator that can intuitively reflect the overall quality level of the steel structure. At the same time, the quality assessment index Q will affect the temperature correction coefficient α. The value range of the quality assessment index Q is between 10 and 100. The quality assessment index Q affects the temperature correction coefficient α. The specific calculation formula is: Quality assessment index Q = 50α; When the quality assessment index Q is 50, α is 1, and no temperature correction is performed. When the quality assessment index Q is 80, α is 1.

6. The α value increases with the increase of the quality assessment index Q, and decreases otherwise. By setting the quality assessment index Q to be associated with the α value, the influence of temperature on the ultrasonic propagation velocity can be dynamically adjusted according to the quality assessment index Q and the quality of ultrasonic detection.

5. The nondestructive testing method for steel structure engineering quality according to claim 4 is characterized in that: In the pre-test preparation step, compressed air is used to spray sand or other abrasives onto the surface of the steel structure to remove rust through impact and friction, chemicals are used to remove oil stains from the steel structure surface, and high-pressure water guns are used to remove coating impurities.

6. The method for nondestructive testing of steel structure engineering quality according to claim 5 is characterized in that: The ultrasonic testing instrument in the pre-test preparation step is an ultrasonic flaw detector, which uses the propagation mode, reflection and transmission characteristics of ultrasonic waves in materials to detect defects, deformations and cracks inside the material.

7. The nondestructive testing method for steel structure engineering quality according to claim 1 is characterized in that: In the detection operation steps, a plurality of servo motors are used to form a multi-degree-of-freedom scanning system for driving the ultrasonic probe and the steel structure to move along a predetermined trajectory. The scanning system includes a computer and a data collector.

8. The nondestructive testing method for steel structure engineering quality according to claim 1 is characterized in that: In the subsequent work steps, the non-destructive testing report includes the project name, structural location, testing method, test results and result judgment. The non-destructive testing report can truly reflect the testing situation and provide clear information for the implementation of steel structure repair and maintenance work.

Images