Trailing Wave-Based Bolt Diameter Measurement Method, System, Storage Medium and Device

Abstract

A method, system, storage medium and device for measuring the diameter of a bolt based on trailing waves, belonging to the technical field of ultrasonic transducer measurement. In order to solve the problem that there is currently no method for measuring the diameter of a bolt in a non-exposed state. The present invention provides a sound source through a transducer arranged on one side of the bolt head, and determines the bolt diameter by using the relationship between the time difference of the N+Lth and Nth trailing waves obtained based on the time difference between the first trailing wave and the second trailing wave and the bolt diameter, or by using the relationship between the time difference of the Nth trailing wave and the longitudinal wave obtained based on the time difference between the first trailing wave and the longitudinal wave and the bolt diameter. The present invention is applicable to the measurement of the diameter of bolts in a non-exposed state.

Description

Technical Field

[0001] The present invention belongs to the technical field of ultrasonic transducer measurement, and particularly relates to a method, a system, a storage medium and a device for measuring the diameter of a bolt based on trailing waves. Background Art

[0002] Bolts are important connection and fastening components, widely used in industries, construction and other fields. Long-term service of bolts may lead to problems such as loosening and deformation. To ensure the reliability of bolts, it is usually necessary to maintain and detect them. Accurately measuring the diameter of bolts on-site helps to quickly replace unqualified bolts and ensure structural safety.

[0003] Currently, the measurement of bolt diameter is based on high-resolution visible light cameras or manual operations, but these methods are only applicable to bolts that are exposed. For bolts buried underground or in the blades of wind turbines, only the bolt head is exposed, and the bolt diameter cannot be directly measured. Moreover, there is a lack of a method for measuring the diameter of high-temperature bolts. Summary of the Invention

[0004] The present invention aims to solve the problem that there is currently no method for measuring the diameter of bolts in a non-exposed state.

[0005] A method for measuring the diameter of a bolt based on trailing waves includes the following steps:

[0006] Providing a sound source through a transducer arranged on one side of the bolt head, and obtaining the acoustic times of N + L times and N times of trailing waves

[0007] Determining the bolt diameter through the following formula:

[0008]

[0009] where d is the bolt diameter, respectively represent the acoustic times of N + L times and N times of trailing waves, and N and L are values used to represent the acoustic times of trailing waves; V L and V S respectively represent the longitudinal wave velocity and the shear wave velocity.

[0010] Further, the determination process of the bolt diameter formula includes the following steps:

[0011] Assume that the acoustic emission angle of the longitudinal wave or shear wave sound source to the side wall boundary is a, and the reflection angle of the SV wave when the longitudinal wave or shear wave sound source encounters the bolt side wall boundary is b; determining the acoustic time difference between the first trailing wave and the second trailing wave as:

[0012]

[0013] where d is the bolt diameter and x is a constant term; V L, V S respectively represent the longitudinal wave and shear wave velocities; respectively represent the acoustic times of the first trailing wave and the second trailing wave;

[0014] According to Snell's law: Simplify the acoustic time difference between the first trailing wave and the second trailing wave to:

[0015]

[0016] Based on the formation principle of the trailing wave in the bolt, the acoustic time difference of the trailing wave is

[0017] Furthermore, determine the bolt diameter as

[0018] A bolt diameter measurement system based on trailing waves, comprising:

[0019] Measurement data acquisition unit: Based on the measurement data of the bolt by the transducer set on one side of the bolt head, acquire the acoustic times of the N + L - th and N - th trailing waves

[0020] Wave velocity acquisition unit: Used to acquire the longitudinal wave and shear wave velocities;

[0021] Bolt diameter calculation unit: Determine the bolt diameter through the following formula:

[0022]

[0023] Wherein, respectively represent the acoustic times of the N + L - th and N - th trailing waves, N and L are values used to represent the acoustic times of the trailing waves; V L , V S respectively represent the longitudinal wave and shear wave velocities.

[0024] A computer storage medium, in which at least one instruction is stored, and the at least one instruction is loaded and run by a processor to run the above - mentioned bolt diameter measurement system based on trailing waves.

[0025] A bolt diameter measurement device based on trailing waves, the device includes a processor and a memory, and at least one instruction is stored in the memory, and the at least one instruction is loaded and run by the processor to run the above - mentioned bolt diameter measurement system based on trailing waves.

[0026] A bolt diameter measurement method based on trailing waves, comprising the following steps:

[0027] Provide a sound source through a transducer set on one side of the bolt head, and acquire the acoustic time of the N - th trailing wave and the acoustic time t of the longitudinal wave L ;

[0028] The bolt diameter is determined by the following formula:

[0029]

[0030] where d is the bolt diameter, represents the acoustic time of the Nth trailing wave, and t L represents the acoustic time of the longitudinal wave; V L and V S represent the longitudinal wave velocity and the shear wave velocity respectively.

[0031] Furthermore, the determination process of the bolt diameter formula includes the following steps:

[0032] Let the acoustic emission angle of the longitudinal wave source to the side wall boundary be a, and the reflection angle of the SV wave when the longitudinal wave source encounters the bolt side wall boundary be b; determine the acoustic time difference between the first trailing wave and the longitudinal wave as:

[0033]

[0034] where d is the bolt diameter, x is a constant term; V L and V S represent the longitudinal wave velocity and the shear wave velocity respectively; t L and represent the acoustic time of the longitudinal wave and the first trailing wave respectively;

[0035] According to Snell's law: Simplify the acoustic time difference between the first trailing wave and the longitudinal wave to

[0036]

[0037] Based on the formation principle of the trailing wave in the bolt, obtain the acoustic time difference of the trailing wave as

[0038] Furthermore, determine the bolt diameter as

[0039] A bolt diameter measurement system based on trailing waves includes:

[0040] Measurement data acquisition unit: Obtain the acoustic time of the Nth trailing wave and the acoustic time t L of the longitudinal wave based on the measurement data of the bolt by the transducer set on one side of the bolt head;

[0041] Wave velocity acquisition unit: Used to obtain the longitudinal wave velocity and the shear wave velocity;

[0042] Bolt diameter calculation unit: Determine the bolt diameter by the following formula:

[0043]

[0044] where d is the bolt diameter, When representing the N - th trailing wave sound time, t L represents the sound time of the longitudinal wave; V L , V S respectively represent the longitudinal wave velocity and the shear wave velocity.

[0045] A computer storage medium stores at least one instruction, and the at least one instruction is loaded and run by a processor to implement the above - mentioned trailing - wave - based bolt diameter measurement system.

[0046] A trailing - wave - based bolt diameter measurement device includes a processor and a memory. The memory stores at least one instruction, and the at least one instruction is loaded and run by the processor to implement the above - mentioned trailing - wave - based bolt diameter measurement system.

[0047] Advantageous effects:

[0048] The present invention first proposes a trailing - wave - based bolt diameter measurement method, which not only provides a new measurement method for measuring the diameter of in - service bolts, but also can measure the diameter of bolts in a hidden state of the screw (i.e., non - exposed bolts). More importantly, the present invention is less affected by temperature and does not require temperature compensation for the sound velocity. It is applicable not only to the measurement of bolt diameters at normal temperature but also to the measurement of bolt diameters at high temperature. Description of the Drawings

[0049] Figure 1 is a schematic diagram of the formation of trailing waves.

[0050] Figure 2 is a schematic diagram of the propagation paths of trailing waves and longitudinal waves in a bolt.

[0051] Figure 3 is a schematic diagram of the ultrasonic signal waveform in a bolt. Detailed Embodiments

[0052] It should be particularly noted that, without conflict, the various embodiments disclosed in this application can be combined with each other. Detailed Embodiment 1:

[0054] This embodiment is a method for measuring the bolt diameter based on the trailing wave. In this embodiment, a transducer is provided on one side of the bolt head to provide a longitudinal wave or a transverse wave sound source. Assuming that the distance between the transducer and the bolt sidewall boundary is d / 2 - xd, it is found through research that for the measurement of the bolt diameter, in this embodiment, the distance between the longitudinal wave sound source and the bolt sidewall boundary can be directly represented by xd for derivation and processing, where d is the bolt diameter and x is a constant term, which is actually a proportionality coefficient. The processing method of the present invention can use a set of transducers to measure the bolt diameters of various sizes.

[0055] The trailing wave is formed by the mode conversion when the longitudinal and transverse waves encounter the bolt sidewall boundary, as Figure 1 shown. The schematic diagram of the propagation paths of the trailing wave and the longitudinal wave in the bolt is as Figure 2 shown. The acoustic emission angle of the longitudinal wave or transverse wave sound source to the sidewall boundary is a, and the reflection angle of the SV wave when the longitudinal wave or transverse wave sound source encounters the bolt sidewall boundary is b.

[0056] The acoustic time difference between the first trailing wave and the longitudinal wave is:

[0057]

[0058] The acoustic time difference between the first trailing wave and the second trailing wave is:

[0059]

[0060] where d is the bolt diameter and x is a constant term; V L 、V S represent the longitudinal wave speed and the transverse wave speed respectively; t L 、 represent the acoustic times of the longitudinal wave, the first trailing wave, and the second trailing wave respectively;

[0061] According to Snell's law:

[0062] Then formula (1) can be simplified to

[0063]

[0064] Formula (2) can be simplified to:

[0065]

[0066] From Figure 1 it can be seen that when the trailing wave is formed in the bolt, the angle a ≈ 90°, then the acoustic time difference of the trailing wave is:

[0067]

[0068] Furthermore, the bolt diameter is determined to be:

[0069]

[0070] Among them, respectively represent the N+L-th and N-th trailing wave sound times.

[0071] The schematic diagram of the ultrasonic signal waveform in the bolt is as Figure 3 shown.

[0072] Since the transverse and longitudinal wave sound velocities of the bolt are determined by the parameters of the material, and the bolt material to be measured is known, the transverse and longitudinal wave sound velocities can be easily obtained. According to the trailing wave sound time difference or the sound time difference between the longitudinal wave and the trailing wave, the diameter of the bolt can be calculated.

[0073] Temperature changes will affect the transverse and longitudinal wave sound velocities. On the one hand, it is difficult to obtain the material parameters of high-temperature bolts. On the other hand, the actual temperature distribution of high-temperature bolts is non-uniform, and it is difficult to obtain the temperature distribution, and it is even more difficult to obtain the accurate value of the sound velocity. Since the molecular term of the present invention uses the trailing wave sound time difference or the sound time difference between the longitudinal wave and the trailing wave for calculation, and the trailing wave propagates at the longitudinal wave sound velocity, and the sound velocities of the two are equally sensitive to temperature, the sound time difference of the numerator of formula (6) is almost unchanged with temperature, and the denominator is based on the sound velocity difference between the transverse wave and the longitudinal wave, reducing the temperature sensitivity. In summary, this method greatly reduces the temperature sensitivity of bolt diameter measurement.

[0074] The transverse and longitudinal wave sound velocities of mild steel at room temperature are 3180 m / s and 5890 m / s respectively. When the temperature is 100 °C, the transverse and longitudinal wave sound velocities are approximately 3150 m / s and 5878 m / s respectively. Based on the true sound velocities at high temperature and room temperature respectively, the difference between the true value and the approximate value of the bolt diameter calculated using formula (6) is 1.26%, which fully meets the accuracy requirements for bolt diameter measurement. Specific Embodiment 2:

[0076] This embodiment is a bolt diameter measurement system based on trailing waves. The system is a program system corresponding to the bolt diameter measurement method based on trailing waves described in this embodiment. The program system can be a bolt diameter measurement method based on trailing waves that calculates the bolt diameter based on the N+L-th and N-th trailing wave sound times or a bolt diameter measurement method based on trailing waves that calculates the bolt diameter based on the N-th trailing wave sound time and the sound time t of the longitudinal wave L for calculating the bolt diameter.

[0077] Specifically,

[0078] (A) A bolt diameter measurement system based on trailing waves, comprising:

[0079] Measurement data acquisition unit: Based on the measurement data of the bolt obtained by the transducer arranged on one side of the bolt head, obtain the N+L-th and N-th trailing wave sound times

[0080] Wave velocity acquisition unit: used to acquire the longitudinal wave and shear wave velocities;

[0081] Bolt diameter calculation unit: determines the bolt diameter through the following formula:

[0082]

[0083] where, respectively represent the acoustic times of the N + L-th and N-th trailing waves, and N and L are values used to represent the acoustic times of the trailing waves; V L and V S respectively represent the longitudinal wave and shear wave velocities.

[0084] (B) A bolt diameter measurement system based on trailing waves, comprising:

[0085] Measurement data acquisition unit: based on the measurement data of the bolt by the transducer arranged on one side of the bolt head, acquires the acoustic time of the N-th trailing wave and the acoustic time t L of the longitudinal wave;

[0086] Wave velocity acquisition unit: used to acquire the longitudinal wave and shear wave velocities;

[0087] Bolt diameter calculation unit: determines the bolt diameter through the following formula:

[0088]

[0089] where, d is the bolt diameter, represents the acoustic time of the N-th trailing wave, t L represents the acoustic time of the longitudinal wave; V L and V S respectively represent the longitudinal wave and shear wave velocities. Specific implementation method three:

[0091] This implementation method is a computer storage medium, and at least one instruction is stored in the storage medium. The at least one instruction is loaded and run by the processor to implement the bolt diameter measurement system based on trailing waves, that is, it can be (A) a bolt diameter measurement system based on trailing waves described in specific implementation method two, or (B) a bolt diameter measurement system based on trailing waves described in specific implementation method two.

[0092] It should be understood that the instructions include a computer program product, software, or computerized method corresponding to any method described in the present invention; the instructions can be used to program a computer system or other electronic devices. A computer storage medium may include a readable medium storing the instructions, which may include, but is not limited to, a magnetic storage medium and an optical storage medium; magneto-optical storage media include read-only memory (ROM), random access memory (RAM), erasable programmable memory (e.g., EPROM and EEPROM), and flash memory layers, or other types of media suitable for storing electronic instructions. Specific Embodiment Four:

[0094] This embodiment is a bolt diameter measuring device based on trailing waves. The device includes a processor and a memory. It should be understood that the device includes any device including a processor and a memory described in the present invention. The device may further include other units and modules for display, interaction, processing, control, etc. through signals or instructions, as well as other functions.

[0095] At least one instruction is stored in the memory, and the at least one instruction is loaded and run by the processor to implement the bolt diameter measuring system based on trailing waves, that is, it may be (A) a bolt diameter measuring system based on trailing waves described in Specific Embodiment Two, or (B) a bolt diameter measuring system based on trailing waves described in Specific Embodiment Two.

[0096] The above numerical examples of the present invention are only for illustrating in detail the calculation model and calculation process of the present invention, rather than limiting the embodiments of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the embodiments here. Any obvious changes or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A bolt diameter measurement method based on trailing wave, characterized in that: The following steps are involved: The transducer set on the side of the bolt head provides a sound source to obtain the N+Lth and Nth tail wave sound time t TN+L ,t TN ; The bolt diameter is determined by the following formula: Where d is the bolt diameter, t TN+L ,t TN Respectively represent N+L times and N times of the tail wave sound, N and L are the values ​​used to represent the tail wave sound; V L 、V S represent the longitudinal and transverse wave velocities respectively; The process of determining the bolt diameter formula includes the following steps: Directly use xd to represent the distance between the longitudinal wave sound source and the bolt side wall boundary for derivation and processing; assume that the acoustic emission angle from the longitudinal wave or transverse wave sound source to the side wall boundary is a, and the SV wave reflection angle of the longitudinal wave or transverse wave sound source encountering the bolt side wall boundary is b; determine the acoustic time difference between the primary trailing wave and the secondary trailing wave as: Where d is the bolt diameter, x is a constant term; V L 、V S Respectively represent the longitudinal wave and transverse wave speed; t T1 ,t T2 They represent the acoustic time of the primary and secondary following waves respectively; According to Snell's law: The acoustic time difference between the primary and secondary trailing waves is simplified as: Based on the principle of the formation of the trailing wave in the bolt, when the trailing wave is formed in the bolt, the angle a≈90°, and the acoustic time difference of the trailing wave is obtained as follows: Then determine the bolt diameter as 2. A computer storage medium, characterized in that: The storage medium stores at least one instruction, and the at least one instruction is loaded and executed by the processor to implement the bolt diameter measurement method based on trailing waves as described in claim 1.

3. A bolt diameter measuring device based on trailing wave, characterized in that: The device comprises a processor and a memory, wherein the memory stores at least one instruction, and the at least one instruction is loaded and executed by the processor for executing the bolt diameter measurement method based on trailing wave as described in claim 1.

4. A bolt diameter measurement method based on trailing wave, characterized in that: The following steps are involved: The transducer set on the side of the bolt head provides the sound source and obtains N times of the trailing wave sound. and the acoustic time t of the longitudinal wave L ; The bolt diameter is determined by the following formula: Where d is the bolt diameter, When N times of following wave sound, t L Indicates the sound duration of longitudinal waves; V L 、V S Respectively represent the longitudinal wave and transverse wave velocities; the process of determining the bolt diameter formula includes the following steps: Directly use xd to represent the distance between the longitudinal wave sound source and the bolt side wall boundary for derivation and processing; assume that the acoustic emission angle from the longitudinal wave sound source to the side wall boundary is a, and the SV wave reflection angle of the longitudinal wave sound source encountering the bolt side wall boundary is b; determine the acoustic time difference between the primary trailing wave and the longitudinal wave as: Where d is the bolt diameter, x is a constant term; V L 、V S Respectively represent the longitudinal wave and transverse wave speed; t L , They represent the acoustic time of the longitudinal wave and the primary trailing wave respectively; According to Snell's law: The acoustic time difference between the primary trailing wave and the longitudinal wave is simplified to Based on the principle of the formation of the trailing wave in the bolt, when the trailing wave is formed in the bolt, the angle a≈90°, and the acoustic time difference of the trailing wave is obtained as follows: Then determine the bolt diameter as 5. A computer storage medium, characterized in that: The storage medium stores at least one instruction, and the at least one instruction is loaded and executed by the processor to execute the bolt diameter measurement method based on trailing wave as described in claim 4.

6. A bolt diameter measuring device based on trailing wave, characterized in that: The device comprises a processor and a memory, wherein at least one instruction is stored in the memory, and the at least one instruction is loaded and executed by the processor to execute the bolt diameter measurement method based on trailing wave as described in claim 4.

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