A dual-probe device for transverse and longitudinal wave bolt stress detection and detection method thereof

Abstract

The present invention relates to a dual-probe device for transverse and longitudinal wave bolt stress detection and a detection method thereof, and belongs to the technical field of ultrasonic non-destructive testing equipment. The invention solves the problem that it is difficult to ensure the positioning accuracy of the dual probes and the constant pressure between the dual probes and the bolts to be tested during the actual use of transverse and longitudinal wave dual-probe stress detection. The invention comprises a housing, a longitudinal wave probe preload adjustment part, a transverse wave probe preload adjustment part, a first spring, a second spring, a longitudinal wave probe, a transverse wave probe, a base and a magnet. The longitudinal wave probe preload adjustment part, a first spring and a longitudinal wave probe are arranged in sequence in the housing. The transverse wave probe preload adjustment part, a second spring and a transverse wave probe are also arranged in sequence in the housing. The housing is detachably connected to the base, and the detection ends of the longitudinal wave probe and the transverse wave probe extend into the base. The invention can well fix the position of the transverse and longitudinal wave dual probes to ensure the stress measurement accuracy; the invention is easy to use and adjust, and can maintain a constant pressure between the bolts to be tested.

Description

Technical Field

[0001] The invention relates to a double-probe device and a detection method thereof, belonging to the technical field of ultrasonic nondestructive detection equipment. Background Art

[0002] With the increase in global energy consumption, the pace of research and development of new energy is also accelerating. New technologies such as hydropower, solar power, biomass power, and wind power have made breakthrough progress and have begun to be vigorously promoted and implemented. In the field of new energy, we also vigorously support the transmission of electricity to the grid, and vigorously promote the construction of new energy through the implementation of price subsidies. Wind energy is a clean and pollution-free renewable energy. The use of wind power for power generation is green and environmentally friendly. In recent years, with the intensification of energy shortages and environmental pollution problems, people have paid more attention to wind power generation. In addition, the competitive advantage of wind power compared to other new energy sources has continued to increase, promoting the rapid development of the wind power industry.

[0003] With the continuous development of wind power technology and the continuous increase in wind power installed capacity, the maintenance and care of wind turbines has been challenged. We need to continuously accelerate the transformation and application of R&D technology in the field of wind power. At present, ultrasonic non-destructive testing technology has been used in the stress detection of wind turbine blade fastening bolts. However, in actual testing, bolts have different lengths due to manufacturing differences and the magnitude of internal stress. The traditional single longitudinal wave method has a complex calibration process, and the change in the measured bolt length will cause a large measurement error, so the scope of application and measurement accuracy cannot be guaranteed.

[0004] Therefore, it is proposed that the bolt stress measurement based on transverse and longitudinal waves can eliminate the influence of length on stress measurement in principle, and the measurement accuracy is high. It can detect the stress of the fastening bolts on the wind turbine blades and replace and repair them in time to avoid irreversible damage, which has a wider application prospect. However, in the actual use of transverse and longitudinal wave dual probe stress detection, it is difficult to ensure the positioning accuracy of the dual probes and the constant pressure between them and the bolts to be tested.

[0005] Therefore, it is urgent to propose a dual-probe device and a detection method for transverse and longitudinal wave bolt stress detection to solve the above technical problems. Summary of the invention

[0006] The purpose of the present invention is to solve the problem that it is difficult to ensure the positioning accuracy of the dual probes and the constant pressure between the dual probes and the bolts to be tested during the actual use of transverse and longitudinal wave stress detection, and to provide a dual probe device and a detection method for transverse and longitudinal wave bolt stress detection. A brief overview of the present invention is given below to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to determine the key or important parts of the present invention, nor is it intended to limit the scope of the present invention.

[0007] The technical solution of the present invention:

[0008] A dual-probe device for transverse and longitudinal wave bolt stress detection comprises a shell, a longitudinal wave probe preload adjustment member, a transverse wave probe preload adjustment member, a first spring, a second spring, a longitudinal wave probe, a transverse wave probe, a base and a magnet. The shell is provided with a longitudinal wave probe preload adjustment member, a first spring and a longitudinal wave probe arranged in sequence. The shell is also provided with a transverse wave probe preload adjustment member, a second spring and a transverse wave probe arranged in sequence. The shell is detachably connected to the base, and the detection ends of the longitudinal wave probe and the transverse wave probe extend into the base.

[0009] Preferably: the sides of the cylindrical longitudinal wave probe preload adjustment member and the shear wave probe preload adjustment member are provided with external threads, and the longitudinal wave probe preload adjustment member and the shear wave probe preload adjustment member are provided with hexagonal countersunk holes at the axis centers.

[0010] Preferably: it also includes a shear wave probe fixing assembly, which includes an outer sleeve and a screw. The side of the outer sleeve is provided with a plurality of equidistantly arranged threaded holes. The outer sleeve is sleeved on the end of the shear wave probe. The screw is inserted into the threaded hole so that the screw is threadedly connected to the outer sleeve. The inserted end of the screw presses against the outer wall of the shear wave probe.

[0011] Preferably: the shell is processed with a first cavity and a second cavity which penetrate axially, one end of the first cavity and the second cavity is processed with a thread, one end of the base is processed with a first detection hole and a second detection hole which are arranged corresponding to the first cavity and the second cavity, and the other end of the base is processed with a detection groove which cooperates with the bolt to be tested, the longitudinal wave probe is arranged in the first cavity, the detection end of the longitudinal wave probe is arranged in the first detection hole, the end of the longitudinal wave probe is provided with a first spring, the longitudinal wave probe preload adjustment piece is threadedly connected to the first cavity, the shear wave probe fixing assembly and the tightening shear wave probe are arranged in the second cavity, the detection end of the tightening shear wave probe is arranged in the second detection hole, the end of the shear wave probe fixing assembly is provided with a second spring, and the shear wave probe preload adjustment piece is threadedly connected to the second cavity.

[0012] Preferably, the magnet comprises a first magnet and a second magnet, two mounting holes are processed on the base, and the first magnet and the second magnet are arranged in the mounting holes.

[0013] A detection method of a dual-probe device for transverse and longitudinal wave bolt stress detection, comprising the following steps:

[0014] Step 1: Put the end of the shear wave probe on the shear wave probe fixing assembly, and fix the shear wave probe and the shear wave probe fixing assembly by adjusting the screws at various positions;

[0015] Step 2: Place the longitudinal wave probe and the shear wave probe in the housing respectively, and then place the first spring and the second spring, rotate the longitudinal wave probe preload adjustment member and the shear wave probe preload adjustment member to connect them with the housing and compress the first spring and the second spring, and the detection ends of the longitudinal wave probe and the shear wave probe extend from the housing;

[0016] Step 3: According to the specifications of the bolt to be tested, select a base of corresponding specifications and place the first magnet and the second magnet into the mounting hole of the base;

[0017] Step 4: Align the detection ends of the longitudinal wave probe and the shear wave probe with the first detection hole and the second detection hole respectively, and then connect the housing and the base with bolts;

[0018] Step 5: Put the base on the bolt to be tested. The magnet on the base will adsorb the dual probe device for transverse and longitudinal wave bolt stress detection on the bolt to be tested.

[0019] Step 6: Adjust the preload force between the longitudinal wave probe, the shear wave probe and the bolt to be tested by rotating the longitudinal wave probe preload force adjustment member and the shear wave probe preload force adjustment member;

[0020] Step 7: From the nonlinear acoustic theory, we know that the speed of ultrasound in the medium is approximately linearly related to the temperature change ΔT, so we can get the longitudinal wave speed v at a certain temperature T. (L，T) , shear wave speed v (S，T) The expression is

[0021] v (L，T) =v L (1-α L ·ΔT) (10)

[0022] v (S，T) =v S (1-α S ΔT) (11)

[0023] Combined with the thermal expansion coefficient β, the transit time t of the longitudinal wave and the transverse wave after the temperature of the bolt changes ΔT under a certain stress is (Lσ，T) , t (Sσ，T) It can be expressed as

[0024] t (Lσ，T) =(1+β·ΔT)·t Lσ / (1-α L ·ΔT) (12)

[0025] t (Sσ·T) =(1+β·ΔT·t Sσ / (1-α S ·ΔT) (13)

[0026] Where: α L , αS are the temperature influence coefficients of longitudinal wave and transverse wave propagating in the bolt respectively;

[0027] The sound-time ratio of the temperature change detection is t (Lσ，T) / t (sσ，T) , the actual sound time ratio t Lσ / t sσ It can be expressed as

[0028]

[0029] Combining equations (10) and (11), we can get

[0030]

[0031]

[0032] Where: t (L，T) , t (S，T) are the transit times of longitudinal and transverse waves at a certain temperature, respectively; t L When it is a longitudinal wave sound, the longitudinal wave transit time can be obtained by cross-correlating the signal received by the longitudinal wave probe; t S When it is a shear wave sound, the shear wave transit time can be obtained by cross-correlating the signal received by the shear wave probe;

[0033] From equations (15) and (16), we can see that the linear relationship between the rate of change of ultrasonic transit time after temperature change and the temperature change ΔT can be achieved. L , α S Calibration; let O = (1-α L ΔT) / (1-α S ΔT), called the temperature-acoustic correction factor, O is only related to ΔT. Substituting it into formula (14) yields the stress σ at a certain temperature. T The expression is

[0034]

[0035] Where: xT is the square of the ratio of the transit time of the longitudinal wave to the transverse wave in the inspection bolt at a certain temperature;

[0036] According to formula (17), after calibrating a1, a2, a3, and o through experiments, it is only necessary to collect the ratio of the longitudinal wave and transverse wave transit time of the bolt to realize the detection of axial stress. At the same time, since a1, a2, and a3 are only related to the material properties of the bolt, and o is only related to the material properties and ΔT of the bolt, the above four parameters are suitable for stress detection and temperature correction between bolts of the same material and different lengths.

[0037] The present invention has the following beneficial effects:

[0038] The present invention can well fix the positions of the transverse and longitudinal wave dual probes to ensure the stress measurement accuracy;

[0039] The present invention is easy to use and adjust, and can maintain a constant pressure between the bolt to be tested, and the measurement parameters of the transverse and longitudinal wave dual probes remain unchanged, and frequent calibration is not required, and can be used for real-time monitoring of the stress of the fastening bolts of wind turbine blades;

[0040] The present invention greatly reduces the number of manual regular inspections, saves a large amount of manpower, material resources and financial resources, and has very good application prospects and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a stereogram of a dual probe device for transverse and longitudinal wave bolt stress detection;

[0042] Figure 2 It is a cross-sectional view of a dual-probe device for transverse and longitudinal wave bolt stress detection;

[0043] Figure 3 An exploded view of a dual-probe setup for transverse and longitudinal wave bolt stress testing.

[0044] In the figure: 1-housing, 2-longitudinal wave probe preload adjustment member, 3-transverse wave probe preload adjustment member, 4-first spring, 5-second spring, 6-transverse wave probe fixing assembly, 7-longitudinal wave probe, 8-transverse wave probe, 9-first magnet, 10-second magnet, 11-base. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0046] Specific implementation method 1: Combination Figure 1-3The present embodiment is described. A dual-probe device for transverse and longitudinal wave bolt stress detection in the present embodiment comprises a shell 1, a longitudinal wave probe preload adjustment member 2, a transverse wave probe preload adjustment member 3, a first spring 4, a second spring 5, a longitudinal wave probe 7, a transverse wave probe 8, a base 11 and a magnet. The shell 1 is provided with a longitudinal wave probe preload adjustment member 2, a first spring 4 and a longitudinal wave probe 7 arranged in sequence. The shell 1 is also provided with a transverse wave probe preload adjustment member 3, a second spring 5 and a transverse wave probe 8 arranged in sequence. The shell 1 is detachably connected to the base 11 by bolts, and the detection ends of the longitudinal wave probe 7 and the transverse wave probe 8 extend into the base 11. The present invention can well fix the positions of the transverse and longitudinal wave dual probes to ensure the stress measurement accuracy. Due to the use of springs and preload adjustment nuts (longitudinal wave probe preload adjustment parts or transverse wave probe preload adjustment parts), it is easy to use and adjust, and can maintain a constant pressure between the bolt to be tested. The measurement parameters of the transverse and longitudinal wave dual probes remain unchanged and do not require frequent calibration. It can be used for real-time monitoring of the stress of wind turbine blade fastening bolts, which can greatly reduce the number of manual regular inspections and save a lot of manpower, material and financial resources. The device can not only be used in the stress measurement of wind turbine blade fastening bolts, but also in all fastening bolt stress measurement and stress monitoring fields such as hydropower generation, and has very good application prospects and application value.

[0047] Specific implementation method 2: Combination Figure 1-3 To illustrate the present embodiment, a dual-probe device for transverse and longitudinal wave bolt stress detection is provided in the present embodiment. The sides of the cylindrical longitudinal wave probe preload adjustment part 2 and the transverse wave probe preload adjustment part 3 both have external threads, and the longitudinal wave probe preload adjustment part 2 and the transverse wave probe preload adjustment part 3 are provided with hexagonal countersunk holes at the axis centers.

[0048] Specific implementation method three: Combination Figure 1-3The present embodiment is described. A dual-probe device for transverse and longitudinal wave bolt stress detection in the present embodiment also includes a transverse wave probe fixing assembly 6. The transverse wave probe fixing assembly 6 includes an outer sleeve and a screw. A plurality of threaded holes arranged at equal intervals are provided on the side of the outer sleeve. The outer sleeve is sleeved on the end of the transverse wave probe 8. The screw (or fastening screw) is inserted into the threaded hole to thread the screw and the outer sleeve. The inserted end of the screw presses against the outer side wall of the transverse wave probe 8. When in use, the transverse wave probe and the longitudinal wave probe are respectively placed in the probe holes corresponding to the clamp base. Since the cross-section of the transverse wave probe is large, it is not easy to fix. , the stability is not high, so a shear wave probe fixing assembly is designed, which includes a probe fixing shell and a fastening screw. The probe fixing shell is put on the shear wave probe, and the probe fixing shell and the shear wave probe are fixed by the fastening screws. The fixture shell (shell 1) with a preload adjustment nut and a spring is fixed to the fixture base (base 11) by screws, and then the fixture base is put on the bolt to be tested. The magnet on the fixture base will firmly adsorb the fixture on the bolt to be tested. The preload adjustment nut on the fixture shell can adjust the preload between the probe and the bolt to be tested.

[0049] Specific implementation method four: Combination Figure 1-3 The present embodiment is described. The present embodiment is a dual-probe device for transverse and longitudinal wave bolt stress detection. The shell 1 is processed with a first cavity and a second cavity of a stepped type that penetrate along the axial direction. One end of the first cavity and the second cavity is processed with a thread. The cross-sectional area of ​​the other end of the first cavity and the second cavity is smaller than the cross-sectional area of ​​other positions of the first cavity and the second cavity. One end of the base 11 is processed with a first detection hole and a second detection hole corresponding to the first cavity and the second cavity. The other end of the base 11 is processed with a detection groove that matches the bolt to be tested. When detecting bolt stress of different diameters, it is only necessary to process fixture bases of different diameters, which will greatly improve the scope of application of the fixture. The first detection hole, the second detection hole and the detection hole are connected to the detection hole. The measuring grooves are connected, the longitudinal wave probe 7 is arranged in the first cavity, the detection end of the longitudinal wave probe 7 is arranged in the first detection hole, the end of the longitudinal wave probe 7 is provided with a first spring 4, the longitudinal wave probe preload adjustment part 2 is threadedly connected to the first cavity and compresses the first spring, the shear wave probe fixing assembly 6 and the tightening shear wave probe 8 are arranged in the second cavity, the detection end of the tightening shear wave probe 8 is arranged in the second detection hole, the end of the shear wave probe fixing assembly 6 is provided with a second spring 5, the shear wave probe preload adjustment part 3 is threadedly connected to the second cavity and compresses the second spring; the outer wall of the shear wave probe fixing assembly 6 is provided with a protrusion, the threaded hole is provided at the protrusion, the inner and outer walls of the second cavity of the shell 1 are provided with grooves, and the protrusions and the grooves are correspondingly arranged.

[0050] Specific implementation method five: Combination Figure 1-3The present embodiment is described as a dual-probe device for transverse and longitudinal wave bolt stress detection. The magnet comprises a first magnet 9 and a second magnet 10. Two mounting holes are processed on the base 11. The first magnet 9 and the second magnet 10 are arranged in the mounting holes.

[0051] Specific implementation method six: Combination Figure 1-3 The present embodiment is described. The present embodiment is a detection method of a dual-probe device for transverse and longitudinal wave bolt stress detection, using a dual-probe device for transverse and longitudinal wave bolt stress detection, comprising the following steps:

[0052] Step 1: Fit the end of the shear wave probe 8 onto the shear wave probe fixing assembly 6, and fix the shear wave probe 8 to the shear wave probe fixing assembly 6 by adjusting the screws at various positions;

[0053] Step 2: Place the longitudinal wave probe 7 and the shear wave probe 8 in the housing 1 respectively, and then place the first spring 4 and the second spring 5, rotate the longitudinal wave probe preload adjustment member 2 and the shear wave probe preload adjustment member 3 to connect them with the housing 1 and compress the first spring 4 and the second spring 5, and the detection ends of the longitudinal wave probe 7 and the shear wave probe 8 extend from the housing 1;

[0054] Step 3: According to the specifications of the bolt to be tested, select a base 11 of corresponding specifications and place the first magnet 9 and the second magnet 10 into the mounting hole of the base;

[0055] Step 4: Align the detection ends of the longitudinal wave probe 7 and the shear wave probe 8 with the first detection hole and the second detection hole respectively, and then connect the housing 1 and the base 11 with bolts;

[0056] Step 5: Put the base 11 on the bolt to be tested, and the magnet on the base will firmly adsorb the dual probe device for transverse and longitudinal wave bolt stress detection on the bolt to be tested;

[0057] Step 6: By rotating the longitudinal wave probe preload adjustment member 2 and the shear wave probe preload adjustment member 3, the preload force between the longitudinal wave probe 7, the shear wave probe 8 and the bolt to be tested is adjusted to complete the clamping and positioning of the bolt to be tested, ensure the positioning accuracy of the dual probes and the constant pressure between the probes and the bolt to be tested, and use the longitudinal wave probe 7 and the shear wave probe 8 for non-destructive testing;

[0058] Step 7: Stress measurement and temperature compensation; Considering that the service process of bolts is usually accompanied by changes in ambient temperature within a certain range, and temperature will have a certain impact on the propagation speed of ultrasonic waves, it is necessary to correct the acoustic time error caused by temperature; on the other hand, since the temperature change is not large, the impact of temperature on the properties of bolt materials is not considered for the time being; from the nonlinear acoustic theory, it can be known that the speed of ultrasonic waves in the medium is approximately linearly related to the temperature change ΔT, so the longitudinal wave speed v at a certain temperature T can be obtained (L，T) , shear wave speed v(S，T) The expression is

[0059] v (L，T) =v L (1-α L ·ΔT) (10)

[0060] v (S，T) =v S (1-α S ΔT) (11)

[0061] The propagation speed of longitudinal and transverse waves in the material under zero stress v L 、v S ;

[0062] Combined with the thermal expansion coefficient β, the transit time t of the longitudinal wave and the transverse wave after the temperature of the bolt changes ΔT under a certain stress is (Lσ，T) , t (Sσ，T) It can be expressed as

[0063] t (Lσ，T) =(1+β·ΔT)·t Lσ / (1-α L ·ΔT) (12)

[0064] t (Sσ，T) =(1+β·ΔT)·t Sσ / (1-α S ·ΔT) (13)

[0065] Where: α L , α S are the temperature influence coefficients of longitudinal wave and transverse wave propagating in the bolt respectively;

[0066] The sound-time ratio of the temperature change detection is t (Lσ，T) / t (Sσ，T) , the transit time t of longitudinal and transverse waves under stress σ Lσ ,t Sσ , the actual sound time ratio t Lσ / t Sσ It can be expressed as

[0067]

[0068] Combining equations (10) and (11), we can get

[0069]

[0070]

[0071] Where: t (L，T) , t (S，T) are the transit times of longitudinal and transverse waves at a certain temperature, respectively; tL When it is a longitudinal wave sound, the longitudinal wave transit time can be obtained by cross-correlating the signal received by the longitudinal wave probe; t S When it is a shear wave sound, the shear wave transit time can be obtained by cross-correlating the signal received by the shear wave probe;

[0072] From equations (15) and (16), we can see that the linear relationship between the rate of change of ultrasonic transit time after temperature change and the temperature change ΔT can be achieved. L , α S Calibration; let ο = (1-α L ΔT) / (1-α S ΔT), is called the temperature-time correction factor, and ο is only related to ΔT. Substituting it into equation (14) yields the stress σ at a certain temperature. T The expression is

[0073]

[0074] Where: xT is the square of the ratio of the transit time of the longitudinal wave and the transverse wave in the inspection bolt at a certain temperature;

[0075] According to formula (17), after calibrating a1, a2, a3, and ο through experiments, it is only necessary to collect the ratio of the longitudinal wave and transverse wave transit time of the bolt to realize the detection of axial stress. At the same time, since a1, a2, and a3 are only related to the material properties of the bolt, and ο is only related to the material properties and ΔT of the bolt, the above four parameters are suitable for stress detection and temperature correction between bolts of the same material and different lengths, which can effectively shorten the preliminary preparation time for large-scale bolt stress detection in engineering applications; the acoustic time (transit time) is calculated by the cross-correlation algorithm based on the echo signal of the probe (longitudinal wave probe 7, transverse wave probe 8); the temperature compensation coefficient is obtained through calibration experiments; the test environment temperature is measured by the equipment temperature sensor;

[0076] The invention solves the problem that the currently disclosed transverse and longitudinal wave detection models are relatively complex, most of which approximate the parameters and do not directly establish the relationship between the transverse and longitudinal wave transit time ratio and the axial stress on the bolt, making the engineering application of these detection models relatively cumbersome. The detection model provided by the present invention directly establishes the relationship between the two, and can correct the effect of temperature on acoustic time according to the change of the detection temperature relative to the calibration temperature, making its engineering application more convenient.

[0077] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be arranged and combined, and those skilled in the art can exhaust all possibilities based on the mathematical knowledge of arrangement and combination. Therefore, the present invention will no longer describe the technical solutions after arrangement and combination one by one, but it should be understood that the technical solutions after arrangement and combination have been disclosed by the present invention.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A detection method for a dual probe device for transverse and longitudinal wave bolt stress detection, using a dual probe device for transverse and longitudinal wave bolt stress detection, comprising a housing (1), a longitudinal wave probe preload adjustment member (2), a transverse wave probe preload adjustment member (3), a first spring (4), a second spring (5), a longitudinal wave probe (7), a transverse wave probe (8), a base (11) and a magnet, wherein the housing (1) is provided with a longitudinal wave probe preload adjustment member (2), a first spring (4) and a longitudinal wave probe (7) arranged in sequence, and the housing (1) is also provided with a transverse wave probe preload adjustment member (3), a second spring (5) and a transverse wave probe (8) arranged in sequence, the housing (1) is detachably connected to the base (11), and the detection ends of the longitudinal wave probe (7) and the transverse wave probe (8) extend into the base (11); The sides of the cylindrical longitudinal wave probe preload adjustment member (2) and the shear wave probe preload adjustment member (3) are both provided with external threads, and the axis centers of the longitudinal wave probe preload adjustment member (2) and the shear wave probe preload adjustment member (3) are provided with hexagonal countersunk holes; It also includes a shear wave probe fixing assembly (6), which includes an outer sleeve and a screw. The side of the outer sleeve is provided with a plurality of threaded holes arranged at equal distances. The outer sleeve is sleeved on the end of the shear wave probe (8). The screw is inserted into the threaded hole so that the screw and the outer sleeve are threadedly connected. The inserted end of the screw is pressed against the outer side wall of the shear wave probe (8). The shell (1) is processed with a first cavity and a second cavity which penetrate axially, and one end of the first cavity and the second cavity is processed with a thread, one end of the base (11) is processed with a first detection hole and a second detection hole which are arranged corresponding to the first cavity and the second cavity, and the other end of the base (11) is processed with a detection groove which cooperates with the bolt to be tested, the longitudinal wave probe (7) is arranged in the first cavity, the detection end of the longitudinal wave probe (7) is arranged in the first detection hole, the end of the longitudinal wave probe (7) is provided with a first spring (4), the longitudinal wave probe preload adjustment member (2) is threadedly connected to the first cavity, the shear wave probe fixing assembly (6) and the tightening shear wave probe (8) are arranged in the second cavity, the detection end of the tightening shear wave probe (8) is arranged in the second detection hole, the end of the shear wave probe fixing assembly (6) is provided with a second spring (5), and the shear wave probe preload adjustment member (3) is threadedly connected to the second cavity; The magnet comprises a first magnet (9) and a second magnet (10); two mounting holes are processed on the base (11); the first magnet (9) and the second magnet (10) are arranged in the mounting holes; Features: The method comprises the following steps: Step 1: Mount the end of the shear wave probe (8) on the shear wave probe fixing assembly (6), and fix the shear wave probe (8) and the shear wave probe fixing assembly (6) by adjusting screws at various positions; Step 2: Place the longitudinal wave probe (7) and the shear wave probe (8) in the housing (1), then place the first spring (4) and the second spring (5), rotate the longitudinal wave probe preload adjustment member (2) and the shear wave probe preload adjustment member (3) to connect them to the housing (1) and compress the first spring (4) and the second spring (5), and the detection ends of the longitudinal wave probe (7) and the shear wave probe (8) extend out of the housing (1); Step 3: According to the specifications of the bolt to be tested, select a base (11) of corresponding specifications and place the first magnet (9) and the second magnet (10) into the mounting hole of the base; Step 4: Align the detection ends of the longitudinal wave probe (7) and the shear wave probe (8) with the first detection hole and the second detection hole respectively, and then connect the housing (1) and the base (11) with bolts; Step 5: Put the base (11) on the bolt to be tested, and the magnet on the base will adsorb the dual probe device for transverse and longitudinal wave bolt stress detection on the bolt to be tested; Step 6: Adjust the preload force between the longitudinal wave probe (7), the shear wave probe (8) and the bolt to be tested by rotating the longitudinal wave probe preload force adjustment member (2) and the shear wave probe preload force adjustment member (3); Step 7: From the nonlinear acoustic theory, we know that the speed of ultrasound in the medium is approximately linearly related to the temperature change ΔT, so we can get the longitudinal wave speed v at a certain temperature T. (LT) , shear wave speed v (S，T) The expression is v (L，T) =v L (1-α L ·ΔT) (10) v (S，T) =v s (1-α s ΔT) (11) Combined with the thermal expansion coefficient β, the transit time t(L) of the longitudinal wave and the transverse wave after the temperature of the bolt changes ΔT under a certain stress σ , T), t (Sσ，T) It can be expressed as t (Lσ，T) =(1+β·ΔT)·t Lσ / (1-a L ·ΔT) (12) t (Sσ,T) =(1+β·ΔT)·t Sσ / (1-a S ·ΔT) (13) Where: α L , α S are the temperature influence coefficients of longitudinal wave and transverse wave propagating in the bolt respectively; The sound-time ratio of the temperature change detection is t (Lσ，T) / t (Sσ，T) , the actual sound time ratio t Lσ / t Sσ It can be expressed as Combining equations (10) and (11), we can get Where: t (L，T) , t (S，T) are the transit times of longitudinal and transverse waves at a certain temperature, respectively; t L When it is a longitudinal wave sound, the longitudinal wave transit time can be obtained by cross-correlating the signal received by the longitudinal wave probe; t S When it is a shear wave sound, the shear wave transit time can be obtained by cross-correlating the signal received by the shear wave probe; From equations (15) and (16), we can see that the linear relationship between the rate of change of ultrasonic transit time after temperature change and the temperature change ΔT can be achieved. L , α S Calibration; let ο = (1-α L ΔT) / (1-α S ΔT), is called the temperature-time correction factor, and ο is only related to ΔT. Substituting it into equation (14) yields the stress σ at a certain temperature. T The expression is Where: x T It is the square of the ratio of the transit time of longitudinal wave and transverse wave in the inspection bolt at a certain temperature; According to formula (17), after calibrating a1, a2, a3, and ο through experiments, it is only necessary to collect the ratio of the longitudinal wave and transverse wave transit time of the bolt to realize the detection of axial stress. At the same time, since a1, a2, and a3 are only related to the material properties of the bolt, and ο is only related to the material properties and ΔT of the bolt, the above four parameters are suitable for stress detection and temperature correction between bolts of the same material and different lengths.

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