CN111537621A - Device and method for ultrasonically detecting bolt stress - Google Patents
Device and method for ultrasonically detecting bolt stress Download PDFInfo
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- CN111537621A CN111537621A CN202010451237.7A CN202010451237A CN111537621A CN 111537621 A CN111537621 A CN 111537621A CN 202010451237 A CN202010451237 A CN 202010451237A CN 111537621 A CN111537621 A CN 111537621A
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- bolt
- ultrasonic
- stress
- hydraulic cylinder
- groove
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
- G01N3/10—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces generated by pneumatic or hydraulic pressure
- G01N3/12—Pressure testing
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/25—Measuring force or stress, in general using wave or particle radiation, e.g. X-rays, microwaves, neutrons
- G01L1/255—Measuring force or stress, in general using wave or particle radiation, e.g. X-rays, microwaves, neutrons using acoustic waves, or acoustic emission
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/04—Analysing solids
- G01N29/07—Analysing solids by measuring propagation velocity or propagation time of acoustic waves
Abstract
The invention discloses a device for detecting bolt stress by ultrasonic waves, which comprises a bottom plate, a hydraulic cylinder, a sliding groove, a limiting plate and a sleeve, wherein the limiting plate is welded at one end of the upper surface of the bottom plate, a limiting groove is formed in the limiting plate, clamping grooves are formed in two sides of the limiting plate, the hydraulic cylinder is arranged at the other end of the upper surface of the bottom plate, a stroke rod is arranged at one end of the hydraulic cylinder, a push block is arranged at one end, away from the hydraulic cylinder, of the stroke rod, a groove is formed in the outer wall of one end, away from the hydraulic cylinder, of the push block, the sleeve is arranged between the hydraulic cylinder and the limiting plate, an ultrasonic generator and an ultrasonic wave acquisition module are arranged in the sleeve, a connecting plate. According to the invention, the hydraulic cylinder is arranged to drive the push block to move, so that the bolt body can be extruded, and the ultrasonic detection of the bolt body is facilitated.
Description
Technical Field
The invention relates to the technical field of ultrasonic detection, in particular to a device and a method for detecting bolt stress by ultrasonic.
Background
The mechanical part of common use in the daily life of bolt, the in-service use scope is very extensive, can be used to each field, if be used for some fields that require very high, and material and the quality requirement to the bolt are very strict, consequently before the bolt is used, need carry out ultrasonic detection to the bolt, carries out the analysis through the stress of ultrasonic wave to the bolt in the atress process, and the staff passes through ultrasonic detection numerical value, judges whether the bolt is applicable to in-service use.
But at the actual testing in-process, need exert external force to the bolt, because the length of bolt is shorter, it has the difficulty to exert external force to the bolt to carry out ultrasonic detection to the bolt not comprehensive enough, can make actual detection inaccurate, mislead the staff easily and produce the erroneous judgement, thereby influence in-service use.
Disclosure of Invention
The present invention is directed to a device for ultrasonically detecting bolt stress, so as to solve the problems mentioned in the background art.
In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides a device of ultrasonic detection bolt stress, includes bottom plate, pneumatic cylinder, spout, limiting plate and sleeve pipe, the welding of bottom plate upper surface one end has the limiting plate, the inside spacing groove of having seted up of limiting plate, the draw-in groove has been seted up to the limiting plate both sides, the bottom plate upper surface other end is provided with the pneumatic cylinder, pneumatic cylinder one end is provided with the stroke pole, the stroke pole deviates from pneumatic cylinder one end and installs the ejector pad, the ejector pad deviates from pneumatic cylinder one end outer wall and offers flutedly, be provided with the sleeve pipe between pneumatic cylinder and the limiting plate, the inside supersonic generator and the ultrasonic wave collection module that are circular array and distribute that is provided with of sleeve pipe, surface mounting has the connecting plate under the sleeve pipe, and the bottom plate upper surface.
Preferably, the clamping groove is communicated with the limiting groove, and the inner wall of the bottom end of the clamping groove is matched with the groove.
Preferably, the bases are symmetrically arranged on the lower surface of the hydraulic cylinder, and the lower ends of the bases are connected with the upper surface of the bottom plate.
Preferably, the bolt body is placed inside the sleeve, and one end of the bolt body is clamped inside the clamping groove.
Preferably, the ultrasonic acquisition modules are symmetrically distributed on two sides of the ultrasonic generator.
Compared with the prior art, the invention has the beneficial effects that: according to the bolt body detection device, the hydraulic cylinder is arranged to drive the push block to extrude the bolt body, so that external force is applied to the bolt body, the groove in the push block can limit one end of the bolt body, the bolt body is kept horizontal by matching with the clamping groove, the bolt body can be conveniently detected by the ultrasonic generator and the ultrasonic acquisition module, ultrasonic waves can comprehensively and accurately detect the bolt body, a worker can manually move the sleeve, the sleeve can move in the sliding groove through the sliding block, the worker can conveniently move the sleeve, the bolt body can be more comprehensively detected, and the actual use effect is better.
Drawings
FIG. 1 is a main sectional structural view of the present invention;
FIG. 2 is a side view of the base plate and sleeve of the present invention;
fig. 3 is a schematic front view of a limiting plate according to the present invention;
FIG. 4 is a flowchart of a bolt stress calculation according to an embodiment of the present invention;
FIG. 5 is a graph showing the relationship between the elongation of each portion of the bolt and the temperature and stress according to an embodiment of the present invention;
fig. 6 is a flowchart of calculating the longitudinal wave sound velocity and the transverse wave sound velocity of the ultrasonic wave according to the embodiment of the present invention.
In the figure: 1. a base plate; 2. a hydraulic cylinder; 3. a base; 4. a trip lever; 5. a push block; 6. a slider; 7. a connecting plate; 8. a chute; 9. a limiting plate; 10. a limiting groove; 11. a card slot; 12. an ultrasonic wave acquisition module; 13. a sleeve; 14. an ultrasonic generator; 15. a bolt body; 16. and (4) a groove.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", "both ends", "one end", "the other end", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "connected," and the like are to be construed broadly, such as "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Referring to fig. 1 to 3, an embodiment of the present invention includes: a device for detecting bolt stress by ultrasonic waves comprises a bottom plate 1, a hydraulic cylinder 2, a sliding groove 8, a limiting plate 9 and a sleeve 13, wherein the limiting plate 9 is welded at one end of the upper surface of the bottom plate 1, a limiting groove 10 is formed in the limiting plate 9, clamping grooves 11 are formed in two sides of the limiting plate 9, the clamping grooves 11 are communicated with the limiting groove 10, the inner wall of the bottom end of each clamping groove 11 is matched with a groove 16, the hydraulic cylinder 2 is arranged at the other end of the upper surface of the bottom plate 1, bases 3 are symmetrically arranged on the lower surface of the hydraulic cylinder 2, the lower end of each base 3 is connected with the upper surface of the bottom plate 1, a stroke rod 4 is arranged at one end of each hydraulic cylinder 2, a pushing block 5 is arranged at the end, which is far away from the hydraulic cylinder 2, a groove 16 is formed in the outer wall of the pushing block 5, the pushing, cooperation draw-in groove 11 keeps bolt body 15 level, and can fix bolt body 15, thereby be convenient for supersonic generator 14 and ultrasonic wave collection module 12 detect bolt body 15, be convenient for the ultrasonic wave can carry out comprehensive and accurate detection to bolt body 15, supersonic generator 14 can send the ultrasonic wave of fixed frequency or movable frequency, the ultrasonic wave is at bolt body 15 surface infiltration and reflection ultrasonic wave, ultrasonic wave collection module 12 can gather the ultrasonic wave, and analysis, thereby help the staff to pass through the external force that pneumatic cylinder 2 applyed after bolt body 15, the stress that receives on the bolt body 15.
A sleeve 13 is arranged between the hydraulic cylinder 2 and the limiting plate 9, a bolt body 15 is placed inside the sleeve 13, one end of the bolt body 15 is clamped inside the clamping groove 11, an ultrasonic generator 14 and an ultrasonic acquisition module 12 which are distributed in a circular array are arranged inside the sleeve 13, the ultrasonic acquisition modules 12 are symmetrically distributed on two sides of the ultrasonic generator 14, and of course, as is well known to those skilled in the art, the ultrasonic acquisition module 12 and the ultrasonic generator 14 are provided with common knowledge, which all belong to conventional means or common general knowledge, and are not described herein again, and the skilled in the art can perform any matching according to the needs or the convenience. Surface mounting has connecting plate 7 under the sleeve pipe 13, and 1 upper surface of bottom plate has seted up spout 8, 8 inside slidable mounting of spout have slider 6, 7 lower extremes of connecting plate are connected with the 6 upper surfaces of slider, but staff manual movement sleeve pipe 13, and sleeve pipe 13 accessible slider 6 removes in spout 8 to the staff of being convenient for removes sleeve pipe 13, can carry out more comprehensive detection to bolt body 15, and the in-service use effect is better.
During operation, the hydraulic cylinder 2 drives the push block 5 to extrude the bolt body 15, so as to apply external force to the bolt body 15, the groove 16 on the push block 5 can limit one end of the bolt body 15, the bolt body 15 is kept horizontal by matching with the clamping groove 11, and the bolt body 15 can be fixed, so that the ultrasonic generator 14 and the ultrasonic acquisition module 12 can detect the bolt body 15 conveniently, the ultrasonic can comprehensively and accurately detect the bolt body 15, the ultrasonic generator 14 can emit ultrasonic with fixed frequency or movable frequency, the ultrasonic permeates and reflects the ultrasonic on the surface of the bolt body 15, the ultrasonic acquisition module 12 can acquire and analyze the ultrasonic, so as to help workers to analyze the stress on the bolt body 15 after the bolt body 15 passes through the external force applied by the hydraulic cylinder 2, and the staff can manually move sleeve pipe 13, and sleeve pipe 13 accessible slider 6 removes in spout 8 to be convenient for the staff to remove sleeve pipe 13, can carry out more comprehensive detection to bolt body 15.
Example two
The invention provides a testing method for bolt stress, which is applied to a device for detecting the bolt stress by ultrasonic waves described in the first embodiment, and the specific method comprises the following steps:
and 4, calculating the stress of the bolt.
Further, in step 1, the relationship between the elongation of each part of the bolt and the temperature and stress is determined based on: the stress of the known bolt can influence the ultrasonic sound velocity, the speed of the ultrasonic wave passing through the bolt can be changed under different stresses, meanwhile, the extension amount of the bolt can be changed due to different pretightening forces, and therefore the relation between the pretightening force and the ultrasonic sound velocity can be converted into the relation between the bolt extension amount and the ultrasonic sound velocity. Meanwhile, due to the influence of temperature, under the condition of the same pretightening force, the elongation of the bolts at different temperatures is different, so that the temperature change needs to be taken into account when the relation between the pretightening force and the ultrasonic sound velocity is calculated.
Further, in step 2 and step 3, determining the longitudinal wave sound velocity of the ultrasonic wave and determining the transverse wave sound velocity of the ultrasonic wave are based on: it is known that the propagation of ultrasonic waves requires a medium, and the main factors influencing the sound velocity when propagating through a solid medium are temperature, stress and uniformity of materials and components.
Generally, as the temperature increases, the sound velocity of the medium decreases; the stress increases, the speed increases, but the increase is slow; therefore, the stress is calculated by the sound velocity of the sound wave, and the temperature and the material condition of the bolt need to be considered. When the longitudinal wave is propagated in the medium, the propagation direction of the wave is consistent with the vibration direction of the mass point; when the transverse wave is transmitted in the medium, the transmission direction of the wave is vertical to the vibration direction of the mass point; therefore, in order to calculate the stress of the bolt more comprehensively, two waves need to be calculated respectively, as shown in fig. 4.
Further, the principle of the method provided by the invention is as follows: based on the influence of the bolt stress on the ultrasonic sound velocity, measuring the acoustic time difference corresponding to the elongation of the bolt under the action of load, establishing the relation between the acoustic time difference and the bolt stress, and obtaining the calculation method of the bolt stress.
According to the technical scheme, the invention provides the testing method for the bolt stress, the ultrasonic measuring method is used, the stress of the bolt used in engineering or equipment is measured based on the acoustoelastic theorem, and the nondestructive measurement of the bolt can be realized. The method provided by the invention is suitable for projects or equipment which have narrow internal space and cannot be provided with sensors, and meanwhile, the stress can be calculated by measuring a small number of parameters.
EXAMPLE III
The invention provides a method for testing bolt stress, which comprises the following steps: determining the relation between the elongation of each part of the bolt and the temperature and stress, determining the longitudinal wave sound velocity of ultrasonic waves, determining the transverse wave sound velocity of the ultrasonic waves, and calculating the bolt stress.
In an embodiment of the present invention, as shown in fig. 5, which is a graph of the relationship between the elongation of each part of the bolt and the temperature and stress determined by the present invention, the elongation of the bolt under load is first calculated, and when the hydraulic cylinder 2 drives the push block 5 to press the bolt body 15:
wherein L isσThe bolt is extended by the pushing block 5 driven by the load hydraulic cylinder 2 to extrude the bolt body 15σ is the stress to which the bolt is subjected, E is the modulus of elasticity of the bolt, r is the spacing between the nuts, and D is the nominal diameter of the bolt.
The elongation of the bolt under the action of temperature is as follows:
Lt＝Lβ△t
in test LtThe elongation of the bolt under the action of temperature, L is the total length of the bolt, β is the thermal expansion coefficient of the bolt material, and △ t is the value of temperature change.
In a second embodiment of the present invention, as shown in fig. 6, which is a flowchart of the present invention for determining longitudinal wave sound and transverse wave sound of ultrasonic waves, first, the longitudinal wave sound velocity and the transverse wave sound velocity of the ultrasonic waves are determined:
VL＝VL0(1+k′Lσ)(1-α△t)
VS＝VS0(1+k′Sσ)(1-α△t)
in-test VLIs the longitudinal wave sound velocity of ultrasonic wave, VSIs the ultrasonic transverse wave sound velocity, VL0Is the sound velocity of ultrasonic longitudinal wave sound velocity under the zero stress of the bolt, VS0Is the sound velocity, k ', of ultrasonic transverse wave sound velocity at zero stress of the bolt'LIs the acoustic elastic coefficient k 'of ultrasonic longitudinal wave in the bolt medium'SThe coefficient of acoustic elasticity of ultrasonic transverse waves in a bolt medium, α the ultrasonic sound velocity temperature coefficient, and △ t the temperature change value.
The above two formulas are combined with the formula in example 1 to obtain the formula for calculating ultrasonic transverse wave sound:
the formula of the ultrasonic longitudinal wave sound time calculation obtained by the same method is as follows:
as shown in fig. 6, it is known that the ultrasonic sound velocity is only related to the temperature under the zero stress condition, and therefore the calculation formula of the ultrasonic transverse wave sound under the zero stress condition is:
the calculation formula of the ultrasonic longitudinal wave sound time under the condition of zero stress is as follows:
in the third embodiment of the present invention, the obtained ultrasonic longitudinal wave and transverse wave sound time formulas under the zero stress condition are respectively substituted into the ultrasonic longitudinal wave and transverse wave calculation formulas, and the obtained two tests are divided to obtain:
it is also known that when the measurement time interval is short, Δ t approaches 0, and therefore the stress of the bolt can be obtained as:
furthermore, the invention can be seen that for different bolts, only the acoustic elastic coefficient k 'of the ultrasonic longitudinal wave in the bolt medium needs to be known'LAcoustic elastic coefficient k 'of ultrasonic transverse wave in bolt medium'SThe distance r between the two nuts and the nominal diameter D of the bolt can be used for calculating the stress of the bolt by the method provided by the invention.
For the embodiment of the method for testing stress of a bolt provided by the present invention, since it is substantially similar to the embodiment of the method for testing stress of a bolt, the relevant points refer to the partial description of the embodiment of the apparatus, and are not repeated herein.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Claims (6)
1. The utility model provides a device of ultrasonic testing bolt stress, includes bottom plate (1), pneumatic cylinder (2), spout (8), limiting plate (9) and sleeve pipe (13), its characterized in that: a limiting plate (9) is welded at one end of the upper surface of the bottom plate (1), a limiting groove (10) is formed in the limiting plate (9), clamping grooves (11) are formed in two sides of the limiting plate (9), a hydraulic cylinder (2) is arranged at the other end of the upper surface of the bottom plate (1), a stroke rod (4) is arranged at one end of the hydraulic cylinder (2), a push block (5) is installed at one end, away from the hydraulic cylinder (2), of the stroke rod (4), a groove (16) is formed in the outer wall of one end, away from the hydraulic cylinder (2), of the push block (5), a sleeve (13) is arranged between the hydraulic cylinder (2) and the limiting plate (9), an ultrasonic generator (14) and an ultrasonic acquisition module (12) which are distributed in a circular array are arranged in the sleeve (13), a connecting plate (7) is installed on, the inside slidable mounting of spout (8) has slider (6), connecting plate (7) lower extreme is connected with slider (6) upper surface.
2. The apparatus for ultrasonically testing stress of a bolt according to claim 1, wherein: the clamping groove (11) is communicated with the limiting groove (10), and the inner wall of the bottom end of the clamping groove (11) is matched with the groove (16).
3. The apparatus for ultrasonically testing stress of a bolt according to claim 1, wherein: the base (3) is symmetrically installed on the lower surface of the hydraulic cylinder (2), and the lower end of the base (3) is connected with the upper surface of the bottom plate (1).
4. The apparatus for ultrasonically testing stress of a bolt according to claim 1, wherein: a bolt body (15) is placed inside the sleeve (13), and one end of the bolt body (15) is clamped inside the clamping groove (11).
5. The apparatus for ultrasonically testing stress of a bolt according to claim 1, wherein: the ultrasonic acquisition modules (12) are symmetrically distributed on two sides of the ultrasonic generator (14).
6. A method for ultrasonically testing stress of a bolt, comprising an apparatus for ultrasonically testing stress of a bolt according to any one of claims 1 to 5, wherein:
step 1, determining the relationship between the elongation of each part of the bolt and the temperature and stress;
step 2, determining the longitudinal wave sound velocity of the ultrasonic wave;
step 3, determining the transverse wave sound velocity of the ultrasonic wave;
step 4, calculating the stress of the bolt;
wherein the elongation in step 1 is obtained by the following method:
wherein L isσFor the bolt, the pushing block (5) is driven by the load hydraulic cylinder (2) to extrude the bolt body (15) to extend, sigma is stress applied to the bolt, E is the elastic modulus of the bolt, r is the distance between nuts, and D is the nominal diameter of the bolt.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010451237.7A CN111537621A (en) | 2020-05-25 | 2020-05-25 | Device and method for ultrasonically detecting bolt stress |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010451237.7A CN111537621A (en) | 2020-05-25 | 2020-05-25 | Device and method for ultrasonically detecting bolt stress |
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| Publication Number | Publication Date |
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| CN111537621A true CN111537621A (en) | 2020-08-14 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202010451237.7A Withdrawn CN111537621A (en) | 2020-05-25 | 2020-05-25 | Device and method for ultrasonically detecting bolt stress |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117030477A (en) * | 2023-07-28 | 2023-11-10 | 广州华立学院 | Ultrasonic-based detection method for locking force of fixing piece |
-
2020
- 2020-05-25 CN CN202010451237.7A patent/CN111537621A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117030477A (en) * | 2023-07-28 | 2023-11-10 | 广州华立学院 | Ultrasonic-based detection method for locking force of fixing piece |
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Application publication date: 20200814 |
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