Horizontal bar strength detection device and detection method

Abstract

The invention belongs to the technical field of detection, and particularly relates to a horizontal bar strength detection device and method, and the method comprises the following steps: S1, determining a to-be-detected region of a horizontal bar; s2, detecting initial longitudinal wave sound time, initial transverse wave sound time and initial signal amplitude of the to-be-detected area in a non-load state of the to-be-detected area, and calculating an initial wave velocity ratio of a longitudinal wave velocity to a transverse wave velocity; s3, sequentially applying a plurality of safe loads to the horizontal bar, and detecting load longitudinal wave sound time, load transverse wave sound time and load signal amplitude under each safe load; s4, calculating the change rate of the load longitudinal wave sound time and the initial longitudinal wave sound time and the change rate of the load transverse wave sound time and the initial longitudinal wave sound time; calculating the change rate of the load signal amplitude and the initial signal amplitude; calculating the change rate of the load wave velocity ratio and the initial wave velocity ratio; and S5, judging whether the strength of the to-be-detected area of the horizontal bar meets requirements or not according to a calculation result. According to the invention, daily detection can be carried out on the installed horizontal bar, and use safety is ensured.

Description

Technical Field

[0001] This invention belongs to the field of testing technology, and in particular to a single bar strength testing device and testing method. Background Technology

[0002] As a core piece of equipment in gymnastics and fitness, the safety of the horizontal bar during use is paramount. Over time, the horizontal bar and its fixing structure can experience a decrease in strength due to metal fatigue, stress concentration, and loose installation. Currently, horizontal bars are typically fixed to the ground and difficult to disassemble. The main problems with strength testing of installed horizontal bars are as follows: 1. Subjective experience judgment: Relying on the experience of instructors or maintenance personnel to shake and visually inspect is unscientific and inaccurate; 2. Destructive testing: Samples must be taken and sent back to the laboratory; not suitable for routine on-site inspections. 3. Limitations of static testing: Most existing mechanical testing equipment is statically loaded and cannot simulate the dynamic impact loads experienced by athletes, which does not match the actual usage conditions. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a single bar strength testing device and testing method, which can perform daily testing on installed single bars to ensure safe use.

[0004] To solve the above problems, the technical solution adopted by the present invention is: a single bar strength testing method, comprising the following steps: S1. Determine the area to be tested on the horizontal bar; S2. Under no-load conditions in the area to be tested, the initial longitudinal wave acoustic time, initial transverse wave acoustic time, and initial signal amplitude of the area to be tested are detected using a pulse echo ultrasonic probe, and the initial wave velocity ratio of the longitudinal wave velocity and the transverse wave velocity is calculated. S3. Apply multiple static safety loads below the yield strength of the single bar material to the single bar in sequence, and use a pulse echo ultrasonic probe to detect the load longitudinal wave acoustic time, load transverse wave acoustic time and load signal amplitude of the test area under each safety load. S4. Calculate the rate of change of the load longitudinal wave acoustic time and the initial longitudinal wave acoustic time under each safe load, and the rate of change of the load transverse wave acoustic time and the initial longitudinal wave acoustic time. Calculate the rate of change of the load signal amplitude relative to the initial signal amplitude under each safe load; Calculate the load wave velocity ratio of P-wave velocity and S-wave velocity under each safe load, and calculate the rate of change of each load wave velocity ratio from the initial wave velocity ratio. S5. Determine whether the strength of the test area of ​​the single bar meets the requirements based on the calculation results.

[0005] Furthermore, in step S1, the area to be tested includes the center of the bar and both ends of the bar.

[0006] Further, in step S5, with the safety load as the abscissa and the sound time change rate, amplitude change rate, and wave velocity ratio change rate as the ordinate, the sound time change rate as a function of the safety load, the amplitude change rate as a function of the safety load, and the wave velocity ratio change rate as a function of the safety load are plotted. The deviations P1, P2, P3 of the sound time change rate measurement curve from the standard sound time curve, the amplitude change rate measurement curve from the standard amplitude curve, and the wave velocity ratio measurement curve from the standard wave velocity ratio curve are calculated.

[0007] Furthermore, P1, P2, and P3 are calculated using normalized mean squared error.

[0008] Furthermore, P1, P2, and P3 are substituted into the strength assessment model Uindex=1-(W1*P1+W2*P2+W3*P3) to calculate the strength assessment index Uindex, where W1, W2, and W3 are weighting coefficients, and W1+W2+W3=1; when the strength assessment index Uindex≥the set threshold, it indicates that the strength of the single bar meets the requirements.

[0009] The single bar strength testing device for the above-mentioned single bar strength testing method includes a horizontal support, with positioning mechanisms at both ends of the support for fixing the support to the single bar support; a support that slides with the support at the top of the support, and a support locking mechanism connected to the support; a load motor and a pulse echo ultrasonic probe are provided on the support, and the load motor is connected to a load transmission mechanism.

[0010] Furthermore, the load transfer mechanism includes a pull rope, one end of which is wound around the main shaft of the load motor, and the other end of which is provided with a hook.

[0011] Furthermore, an adjusting block is provided on the upper surface of the support. The adjusting block slides with the support in a horizontal direction perpendicular to the main shaft of the load motor. An adjusting shaft is provided on the top of the adjusting block, and an adjusting wheel is provided on the adjusting shaft. The adjusting wheel is higher than the load motor. The upper end of the pull rope is connected to a mounting plate after passing through an adjusting wheel, and the mounting plate is connected to the hook through a tension sensor; The side wall of the mounting plate is provided with a lifting block that slides with the mounting plate. The lifting block is connected to a height adjustment mechanism. The pulse echo ultrasonic probe is located on the top of the lifting block, and a single bar accommodating gap is provided between the pulse echo ultrasonic probe and the hook.

[0012] Furthermore, the positioning mechanism is a clamp.

[0013] The beneficial effects of the present invention are: 1. The present invention can fix the horizontal bar strength testing device on the horizontal bar support at both ends of the installed horizontal bar, and then perform the measurement, which can realize daily maintenance and measurement, and help ensure the safety of athletes.

[0014] 2. This invention applies multi-level loads to the monobar, using controllable and progressive static / quasi-static loading to simulate the mechanical effects of dynamic use, ensuring safety while obtaining crucial data. Ultrasonic waves can penetrate the metal, enabling non-destructive testing of the monobar's internal structure; the test data can then be used to assess whether the monobar's strength meets requirements. Attached Figure Description

[0015] Figure 1 This is a flowchart of the single bar strength detection method of the present invention; Figure 2 This is a front view schematic diagram of the single bar strength testing device of the present invention in use; Figure 3 yes Figure 2 Schematic diagram of the cross section of AA; Figure 4 yes Figure 2 Cross-sectional view of BB; Reference numerals: 1—Bracket; 2—Support; 3—Support locking mechanism; 4—Load motor; 5—Adjusting block; 7—Pulse echo ultrasonic probe; 8—Pull rope; 9—Hook; 10—Adjusting shaft; 11—Adjusting wheel; 12—Mounting plate; 13—Tension sensor; 14—Lifting block; 15—Clamping hoop. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] The single bar strength detection method of the present invention, such as Figure 1 As shown, it includes the following steps: S1. Determine the area to be tested on the horizontal bar.

[0018] The area to be tested is usually the area that is prone to damage. The horizontal bar is a horizontal beam simply supported at both ends. When a load is applied at its center, the center point will generate the largest bending displacement and bending moment, and is most prone to fatigue and micro-cracks. Moreover, when athletes exercise, the force applied to the horizontal bar is usually located at the center of the horizontal bar. Therefore, the area to be tested includes the center of the horizontal bar.

[0019] The connection points between the two ends of the horizontal bar and the support pillars are high-stress areas, which are prone to cracking. Therefore, the test area also includes the two ends of the horizontal bar.

[0020] S2. Under no-load conditions in the test area, the initial longitudinal wave acoustic time Ts0, initial transverse wave acoustic time Tp0 and initial signal amplitude A0 of the test area are detected using a pulse echo ultrasonic probe, and the initial wave velocity ratio C0 of the longitudinal wave velocity Vs0 and the transverse wave velocity Vp0 is calculated.

[0021] Pulse-echo ultrasonic probes can both emit and receive reflected ultrasonic waves. Under the natural state of a monorail with zero external load, the initial longitudinal wave time Ts0, initial transverse wave time Tp0, and initial signal amplitude A0 of the area to be measured are detected. Based on the measured initial longitudinal wave time Ts0, the initial longitudinal wave velocity Vs0 is calculated using the formula Vs0 = d1 / Ts0. Based on the measured initial transverse wave time Tp0, the initial transverse wave velocity Vp0 is calculated using the formula Vp0 = d2 / Tp0, where d1 is the diameter of the monorail and d2 is the length of the ultrasonic wave propagation path. Then, the initial velocity ratio C0 of the longitudinal wave velocity Vs0 and the transverse wave velocity Vp0 is calculated using the formula C = Vs0 / Vp0.

[0022] S3. Apply multiple static safety loads, each lower than the yield strength of the bar material, to the bar in sequence. Specifically, the safety loads can be applied in stages from small to large. At the same time, use a pulse-echo ultrasonic probe to detect the load longitudinal wave acoustic time Ts1, load transverse wave acoustic time Tp1, and load signal amplitude A1 of the test area under each safety load.

[0023] S4. Calculate the rate of change k between the load P-wave acoustic time Ts1 and the initial P-wave acoustic time Ts0 under each safe load. T1 And the rate of change k of Tp1 during the load shear wave sound and Tp0 during the initial longitudinal wave sound. T2 The calculation formula is: k T1 =(Ts1-Ts0) / Ts0,k T2 = (Tp1-Tp0) / Tp0.

[0024] Calculate the rate of change K of the load signal amplitude A1 and the initial signal amplitude A0 under each safe load. A The calculation formula is: K A =(20 / L)*log10(A1 / A0), where L is the ultrasonic wave propagation distance.

[0025] Calculate the load-velocity ratio C1 of the P-wave velocity Vs1 and S-wave velocity Vp1 under each safe load, and calculate the rate of change k of each load-velocity ratio C1 relative to the initial velocity ratio C0. C The calculation formula is: k C =C1-C0, C1 = Vs1 / Vp1; Vs1 = d1 / Ts1, Vp1 = d2 / Tp1.

[0026] S5. Determine whether the strength of the test area of ​​the single bar meets the requirements based on the calculation results.

[0027] k T1 and k T2 This reflects the acoustoelastic stress coefficient of the monobar. For healthy, homogeneous metallic materials, k T1 and k T2 It should be a stable value. If microplastic deformation or an increase in dislocation density occurs within the material due to fatigue, its acoustoelastic relationship will change, i.e., k T1 and k T2 Since it deviates from the normal value, k can be calculated. T1 and k T2 The degree of deviation from the normal value determines the extent of microplastic deformation or dislocation inside the bar.

[0028] K A The attenuation coefficient reflects the amplitude of the ultrasonic signal. In healthy materials, the attenuation changes linearly with stress. When there are many micro-cracks, voids, or other scatterers within the material, these defects will open and interact under stress, causing a large amount of ultrasonic energy to be scattered and absorbed, which is reflected in the attenuation coefficient K of the ultrasonic signal amplitude. A It increases rapidly under specific loads.

[0029] Wave velocity ratio is highly sensitive to material anisotropy and microstructure. Fatigue damage and residual stress alter the elastic anisotropy of the material, causing the wave velocity ratio to deviate from its healthy state as a function of load. C It reflects the change in wave velocity ratio, based on k C The value can be used to determine whether the material is healthy.

[0030] Specifically, it has been determined that: With the safe load as the x-axis and the rate of change of sound time (k) as the y-axis... T1 and k T2 Using the rate of change of amplitude and the rate of change of wave velocity ratio as the ordinates, respectively, we plot the time-of-sound measurement curves for the rate of change of sound time with safe load, the amplitude measurement curves for the rate of change of amplitude with safe load, and the wave velocity ratio measurement curves for the rate of change of wave velocity ratio with safe load. To plot, we first plot multiple points, then connect them sequentially using a smooth curve.

[0031] Next, the deviations P1, P2, P3, and P3 of the acoustic time measurement curve and the standard acoustic time curve, respectively, are calculated. The standard acoustic time curve, standard amplitude curve, and standard wave velocity ratio curve are obtained by measuring and calculating a brand-new, healthy monobar. The measurement and calculation process for a brand-new, healthy monobar is the same as steps S1 to S4. The greater the deviation between the measured curves and the standard curves, the more internal defects there are in the monobar, and the lower its strength. Therefore, by calculating the deviations between the measured curves and the standard curves, it can be determined whether the strength of the monobar meets the requirements.

[0032] The deviation between the two curves can be calculated using existing methods, such as using normalized mean square error (MSE) to calculate P1, P2, and P3. The calculation is called: MSE = (1 / n)×Σ(yᵢ-zᵢ)², where n is the number of sampling points, yᵢ is the ordinate of the standard curve at the sampling point, and zᵢ is the ordinate of the measured curve at the sampling point.

[0033] Calculate the baseline value Base of the standard curve: Base = (1 / n) × Σ(yᵢ²).

[0034] Calculate the relative deviation P: P=min(MSE / Base,1), and take 1 if it exceeds 1 to ensure interval constraints.

[0035] To more intuitively derive the strength assessment value of the horizontal bar, P1, P2, and P3 are substituted into the strength assessment model Uindex = 1 - (W1*P1 + W2*P2 + W3*P3) to calculate the strength assessment index Uindex. Here, W1, W2, and W3 are weighting coefficients, which can be determined empirically, and W1 + W2 + W3 = 1. When the strength assessment index Uindex ≥ the set threshold, it indicates that the horizontal bar's strength meets the requirements. The higher the Uindex value, the higher the strength of the horizontal bar. For example, the set threshold could be 0.8. When Uindex ≥ 0.8, it indicates that the horizontal bar's strength meets the requirements; when Uindex < 0.8, the horizontal bar needs to be discarded; when Uindex ≥ 0.9, it indicates that the horizontal bar's strength fully meets the requirements, its health level is high, and it can be tested again after a longer period.

[0036] The single bar strength detection device of the present invention, such as Figures 2 to 4 As shown, it includes a horizontal support 1, which can be welded from aluminum profiles. Its length is adapted to the length of the horizontal bar. In order to facilitate the movement of this testing device, a set of rollers can be set at the bottom of the support 1. During testing, the support 1 can be pushed to walk on the ground so as to move the testing device to the position of the horizontal bar.

[0037] The support frame 1 has positioning mechanisms at both ends for fixing it to the horizontal bar support. The two ends of the horizontal bar are mounted on the ground via vertical horizontal bar supports. Since the horizontal bar is typically quite tall, to reduce the height of the detection device, the support frame 1 is fixed to the horizontal bar support using positioning mechanisms, ensuring the support frame 1 is at a suitable height. To facilitate the fixing and disassembly of the support frame 1, the positioning mechanism can be a clamp 15. The clamp 15 can be U-shaped, allowing the horizontal bar support to enter through an opening in the clamp 15. The clamp 15 can be connected to the horizontal bar support using multiple screws, ensuring the stability of the support frame 1 and preventing movement when a safe load is applied to the horizontal bar.

[0038] The top of the support 1 is equipped with a support 2 that slides with the support 1. The support 2 can slide along the length of the support 1, thus moving to either end or the center of the support 1. The support 2 is connected to a support locking mechanism 3, which is used to position the support 2. When the support 2 moves to the target position, the support locking mechanism 3 locks the support 2, so that the position of the support 2 can be fixed. The support locking mechanism 3 can be a locking screw. The support 1 has multiple threaded holes, and the locking screw can mate with the threaded holes. The support 2 is equipped with a load motor 4 and a pulse echo ultrasonic probe 7. The load motor 4 is connected to a load transfer mechanism. The load motor 4 is used to provide a safe load. During testing, the load transfer mechanism is connected to the test area of ​​the monorail, so that the load output by the load motor 4 can be transferred to the monorail. After the pulse echo ultrasonic probe 7 is coupled to the monorail, it can emit ultrasonic waves toward the monorail and receive the ultrasonic waves reflected by the monorail, thereby obtaining test data, such as longitudinal wave time, transverse wave time, and signal amplitude.

[0039] When using this single-bar strength testing device, the support is horizontally fixed to the two single-bar supports by the positioning mechanism. Then, the load transfer mechanism is connected to the test area of ​​the single bar, and the pulse-echo ultrasonic probe 7 is coupled to the test area of ​​the single bar. Next, with the load motor 4 not outputting torque, the pulse-echo ultrasonic probe 7 performs ultrasonic testing on the test area, completing step S2. Then, the load motor 4 outputs various different torques in sequence. The torque is converted into tension through the load transfer mechanism, and the tension is transmitted to the single bar, completing step S3. The data detected by the pulse-echo ultrasonic probe 7 can be transmitted to a computing element, such as a PLC processor, which automatically calculates the data and obtains the results.

[0040] The load transfer mechanism can utilize various existing components capable of transmitting tension, such as a pull rod. To reduce the weight of the load transfer mechanism, facilitate its connection to the horizontal bar, and simplify storage, the load transfer mechanism of this invention includes a pull rope 8. The pull rope 8 can be made of sufficiently strong steel wire rope. One end of the pull rope 8 is wound around the main shaft of the load motor 4, and the other end is equipped with a hook 9. During testing, the hook 9 is simply attached to the area to be tested on the horizontal bar. After testing, the hook 9 is removed, making operation convenient. The pull rope 8 is then wound back onto the main shaft of the load motor 4 for compact storage.

[0041] During athlete training, the most common load applied to the horizontal bar is a vertically downward load, such as in pull-ups. However, during some movements, such as swings and rotations, the direction of the load applied to the horizontal bar changes, potentially changing from vertically downward to inclined downward. To improve the flexibility of detection, the load transfer mechanism can apply loads at multiple angles to the horizontal bar. This invention includes an adjusting block 5 on the upper surface of the support 2. The adjusting block 5 slides with the support 2 in a horizontal direction perpendicular to the main shaft of the load motor 4. The sliding direction of the adjusting block 5 is perpendicular to the length direction of the support 1. After reaching the target position, the adjusting block 5 can be fixed with locking screws. An adjusting shaft 10 is located at the top of the adjusting block 5. Both ends of the adjusting shaft 10 are mounted to the adjusting block 5 via bearings, and the adjusting shaft 10 can move synchronously with the adjusting block 5. An adjusting wheel 11 is fixedly mounted on the adjusting shaft 10, and the height of the adjusting wheel 11 is higher than that of the load motor 4.

[0042] The upper end of the pull rope 8 is connected to a mounting plate 12 after passing through an adjusting wheel 11. The mounting plate 12 is connected to the hook 9 via a tension sensor 13. When the adjusting wheel 11 moves, the angle of the pull rope 8 above the adjusting wheel 11 can be changed, thereby changing the load angle transmitted from the pull rope 8 to the horizontal bar, allowing multiple angles of load to be applied to the horizontal bar. The tension sensor 13 detects the magnitude of the tension force transmitted to the horizontal bar, which reflects the magnitude of the load on the horizontal bar.

[0043] Mounting plate 12 is used to mount the pulse-echo ultrasonic probe 7. Mounting plate 12 changes angle with the pull rope 8 to ensure the pulse-echo ultrasonic probe 7 and hook 9 are always positioned on either side of the bar. Specifically, the side wall of mounting plate 12 is provided with a lifting block 14 that slides with the mounting plate 12. The lifting block 14 is connected to a height adjustment mechanism. The pulse-echo ultrasonic probe 7 is positioned on top of the lifting block 14, and a bar-accommodating gap is provided between the pulse-echo ultrasonic probe 7 and hook 9. The height adjustment mechanism can be a stud and multiple guide posts, all of which are clearance-fitted with the lifting block 14. An adjusting nut is provided on the stud on the lower surface of the lifting block 14. By rotating the adjusting nut, the height of the lifting block 14 can be adjusted. During testing, the angle of the pull rope 8 is first adjusted using the adjusting block 5, and then the height of the lifting block 14 is adjusted using the height adjustment mechanism to ensure effective coupling between the pulse-echo ultrasonic probe 7 and the bar, after which testing can be performed. The pulse-echo ultrasonic probe 7 uses this installation method to ensure that the direction of the ultrasonic wave is consistent with the direction of the load during each test, thereby ensuring the accuracy of the test.

[0044] A storage slot can be made on the upper surface of the support 2. After the test is completed, the side of the mounting plate 12 without the pulse echo ultrasonic probe 7 is placed downwards into the storage slot, and then the pull rope 8 is tightened.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for testing the strength of a single bar, characterized in that, Includes the following steps: S1. Determine the area to be tested on the horizontal bar; S2. Under no-load conditions in the area to be tested, the initial longitudinal wave acoustic time, initial transverse wave acoustic time, and initial signal amplitude of the area to be tested are detected using a pulse echo ultrasonic probe, and the initial wave velocity ratio of the longitudinal wave velocity and the transverse wave velocity is calculated. S3. Apply multiple static safety loads below the yield strength of the single bar material to the single bar in sequence, and use a pulse echo ultrasonic probe to detect the load longitudinal wave acoustic time, load transverse wave acoustic time and load signal amplitude of the test area under each safety load. S4. Calculate the rate of change of the load longitudinal wave acoustic time and the initial longitudinal wave acoustic time under each safe load, and the rate of change of the load transverse wave acoustic time and the initial longitudinal wave acoustic time. Calculate the rate of change of the load signal amplitude relative to the initial signal amplitude under each safe load; Calculate the load wave velocity ratio of P-wave velocity and S-wave velocity under each safe load, and calculate the rate of change of each load wave velocity ratio from the initial wave velocity ratio. S5. Determine whether the strength of the test area of ​​the single bar meets the requirements based on the calculation results.

2. The method for testing the strength of a single bar as described in claim 1, characterized in that, In step S1, the area to be tested includes the center of the bar and both ends of the bar.

3. The method for testing the strength of a single bar as described in claim 1, characterized in that, In step S5, with the safe load as the abscissa and the sound time change rate, amplitude change rate, and wave velocity ratio change rate as the ordinate, the sound time change rate as a function of the safe load, the amplitude change rate as a function of the safe load, and the wave velocity ratio change rate as a function of the safe load are plotted. The deviations P1, P2, P3 of the sound time change rate measurement curve from the standard sound time curve, the amplitude change rate measurement curve from the standard amplitude curve, and the wave velocity ratio measurement curve from the standard wave velocity ratio curve are calculated.

4. The method for testing the strength of a single bar as described in claim 3, characterized in that, P1, P2, and P3 were calculated using normalized mean squared error.

5. The method for testing the strength of a single bar as described in claim 3, characterized in that, Substitute P1, P2, and P3 into the strength assessment model Uindex=1-(W1*P1+W2*P2+W3*P3) to calculate the strength assessment index Uindex, where W1, W2, and W3 are weighting coefficients, and W1+W2+W3=1; when the strength assessment index Uindex≥the set threshold, it indicates that the strength of the single bar meets the requirements.

6. A single bar strength testing device for the single bar strength testing method of claim 1, characterized in that, The system includes a horizontal support (1), with positioning mechanisms at both ends for fixing the support (1) to the support bar support; a support (2) that slides with the support (1) is provided on the top of the support (1), and a support locking mechanism (3) is connected to the support (2); a load motor (4) and a pulse echo ultrasonic probe (7) are provided on the support (2), and a load transmission mechanism is connected to the load motor (4).

7. The single bar strength testing device as described in claim 6, characterized in that, The load transfer mechanism includes a pull rope (8), one end of which is wound around the main shaft of the load motor (4), and the other end of which is provided with a hook (9).

8. The single bar strength testing device as described in claim 7, characterized in that, An adjusting block (5) is provided on the upper surface of the support (2). The adjusting block (5) slides with the support (2) in a horizontal direction perpendicular to the main shaft of the load motor (4). An adjusting shaft (10) is provided on the top of the adjusting block (5). An adjusting wheel (11) is provided on the adjusting shaft (10). The adjusting wheel (11) is higher than the load motor (4). The upper end of the pull rope (8) is connected to the mounting plate (12) after passing through the adjusting wheel (11), and the mounting plate (12) is connected to the hook (9) through the tension sensor (13); The side wall of the mounting plate (12) is provided with a lifting block (14) that slides with the mounting plate (12). The lifting block (14) is connected to a height adjustment mechanism. The pulse echo ultrasonic probe (7) is located on the top of the lifting block (14), and a single bar accommodating gap is provided between the pulse echo ultrasonic probe (7) and the hook (9).

9. The single bar strength testing device as described in claims 6, 7, or 8, characterized in that, The positioning mechanism is a clamp (15).

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