Ultrasonic longitudinal wave steel structure stress detection temperature correction device

Abstract

The utility model provides an ultrasonic longitudinal wave steel structure stress detection temperature correction device which comprises a stress steel plate, a correction steel plate, an ultrasonic transmitter and an ultrasonic receiver. The stress steel plate and the correction steel plate are made of the same material; the correction steel plate is stacked on the surface of the stress steel plate, and one end of the correction steel plate is fixedly connected with the stress steel plate; ultrasonic transmitters and ultrasonic receivers are mounted on the stress steel plate and the correction steel plate, and ultrasonic waves transmitted by the ultrasonic transmitters are parallel to stress on the stress steel plate; the distance between the ultrasonic transmitter and the ultrasonic receiver on the stress steel plate is equal to the distance between the ultrasonic transmitter and the ultrasonic receiver on the correction steel plate. The influence of temperature can be eliminated, and the accurate stress can be obtained. The method is high in practicability, simple in structure, excellent in economical efficiency, free of damage to the structure and capable of being popularized and applied to temperature influence correction in stress tests of existing and newly-built steel structures on a large scale.

Description

Technical Field

[0001] The utility model relates to the technical field of steel structure stress detection, in particular to an ultrasonic longitudinal wave steel structure stress detection temperature correction device. Background Art

[0002] At present, the stress detection of steel structures mainly adopts the method of measuring strain after sticking resistance strain gauges, Zhenxuan strain gauges, and fiber Bragg grating strain gauges on the surface of steel plates and then converting them into stress. However, these methods can only measure the stress after sticking, and cannot measure the stress before sticking. However, many existing steel structures did not install relevant measuring equipment during construction or the equipment was damaged, and the actual force size could not be measured. However, building collapse incidents occur frequently. In 2023 alone, 209,000 houses collapsed due to disasters, causing heavy losses to people’s property. How to prevent house collapse accidents and improve building safety is an important issue that needs to be solved urgently.

[0003] When ultrasonic waves propagate in steel structures, if stress changes, the wave velocity will also change. However, if the temperature of the steel plate itself changes due to ambient temperature, the wave velocity will also change. For example, the effect of a 10°C change in temperature on the wave velocity is equivalent to the effect of a stress change of 80MPa on the wave velocity. For general steel structures with stresses of 100 to 200MPa, the temperature effect must be eliminated to accurately identify the true stress. There are also correction methods available, but these methods take into account the baseline temperature before the steel structure is stressed, the effect of grain differences of different materials on the wave velocity, etc., making the stress detection of steel structures not accurate enough. Utility Model Content

[0004] In view of the above problems existing in the prior art, the technical problem to be solved by the utility model is that when ultrasonic waves are used to detect the stress of steel structures, the influence of the reference temperature of the steel structure before being subjected to stress and the grain difference of different materials on the wave velocity make the stress detection of the steel structure not accurate enough.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions: an ultrasonic longitudinal wave steel structure stress detection temperature correction device, comprising: a stress-bearing steel plate, a correction steel plate, an ultrasonic transmitter and an ultrasonic receiver; the stress-bearing steel plate and the correction steel plate are made of the same material; the correction steel plate is stacked on the surface of the stress-bearing steel plate, and one end of the correction steel plate is fixedly connected to the stress-bearing steel plate; the stress-bearing steel plate and the correction steel plate are both equipped with an ultrasonic transmitter and an ultrasonic receiver, and the ultrasonic wave emitted by the ultrasonic transmitter is parallel to the stress on the stress-bearing steel plate; and the spacing between the ultrasonic transmitter and the ultrasonic receiver on the stress-bearing steel plate is the same as the spacing between the ultrasonic transmitter and the ultrasonic receiver on the correction steel plate.

[0006] Preferably, it further comprises a fixing bolt, a fixing hole is opened at one end of the correction steel plate, and one end of the fixing bolt passes through the fixing hole and is threadedly connected to the stress-bearing steel plate.

[0007] Preferably, it also includes a guide bolt, and a long movable hole is opened at one end of the correction steel plate away from the fixing hole, and the long movable hole is arranged parallel to the stress; one end of the guide bolt passes through the long movable hole and is threadedly connected to the stressed steel plate.

[0008] Preferably, the fixed holes and the long movable holes are arranged in plurality in the width direction of the correction steel plate.

[0009] Preferably, the width of the stress-bearing steel plate is greater than the width of the correction steel plate.

[0010] Compared with the prior art, the utility model has at least the following advantages:

[0011] In the utility model, a correction steel plate is placed on the surface of the stressed steel plate to be tested, and the same material is used; then one end of the correction steel plate is fixed to the stressed steel plate; the purpose is that when the stressed steel plate is deformed under the action of stress, the correction steel plate is not affected and always maintains a stress-free state; but when the ambient temperature changes, the stressed steel plate and the correction steel plate shrink and stretch synchronously, and the deformation of the correction steel plate is always consistent with that of the stressed steel plate; then, ultrasonic emission points and ultrasonic receiving points are set on the surfaces of the stressed steel plate and the correction steel plate in parallel with the force direction and at the same interval l; synchronously measure t0+△t t and t0+△t+△t t ; Then, based on the above theory, the influence of temperature is eliminated to obtain the accurate stress value. It is highly practical, simple in structure, economical, and harmless to the structure. It can be widely promoted and applied to the correction of temperature influence generated in stress testing of existing and newly built steel structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the specific implementation of the utility model, the following will briefly introduce the drawings required for use in the specific implementation. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0013] Figure 1 This is a schematic diagram of an ultrasonic steel structure stress detection temperature correction device provided in an embodiment of the present utility model.

[0014] Figure numerals: 1-stressed steel plate, 2-correction steel plate, 3-ultrasonic transmitter, 4-ultrasonic receiver, 5-fixed hole, 6-long movable hole. DETAILED DESCRIPTION

[0015] The following embodiments of the technical solution of the utility model are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the utility model, and are therefore only used as examples, and cannot be used to limit the protection scope of the utility model.

[0016] In the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0017] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] See also Figure 1 , the embodiment provided by the utility model: an ultrasonic longitudinal wave steel structure stress detection temperature correction device, characterized in that it includes: a stress-bearing steel plate 1, a correction steel plate 2, an ultrasonic transmitter 3 and an ultrasonic receiver 4; the stress-bearing steel plate 1 and the correction steel plate 2 are made of the same material; the correction steel plate 2 is stacked on the surface of the stress-bearing steel plate 1, and one end of the correction steel plate 2 is fixedly connected to the stress-bearing steel plate 1; the stress-bearing steel plate 1 and the correction steel plate 2 are both equipped with an ultrasonic transmitter 3 and an ultrasonic receiver 4, and the ultrasonic wave emitted by the ultrasonic transmitter 3 is parallel to the stress on the stress-bearing steel plate 1; and the spacing between the ultrasonic transmitter 3 and the ultrasonic receiver 4 on the stress-bearing steel plate 1 is the same as the spacing between the ultrasonic transmitter 3 and the ultrasonic receiver 4 on the correction steel plate 2. Further, the width of the stress-bearing steel plate 1 is greater than the width of the correction steel plate 2. Thus, an area for installing the ultrasonic transmitter 3 and the ultrasonic receiver 4 can be reserved on the surface of the stress-bearing steel plate 1.

[0019] In a unidirectionally stressed steel structure, the relationship between ultrasonic propagation velocity and stress under reference temperature + temperature change and reference temperature + temperature change + stress is as follows:

[0020]

[0021] Where: ρ0 is the steel density; l is the propagation distance; t0 is the reference propagation time; △t is the propagation time change caused by stress; △t tWave velocity change caused by temperature change; λ, μ, m, l are elastic parameters; σ is steel stress; E is steel elastic modulus.

[0022] From the formula, we can see that the variables are t0+△t t t0+△t+△t t and σ, the remaining variable σ can be obtained as long as the first two variables are known.

[0023] In the specific implementation, a correction steel plate 2 is placed on the surface of the stressed steel plate 1 to be tested, using the same material; then one end of the correction steel plate 2 is fixed to the stressed steel plate 1; the purpose is that when the stressed steel plate 1 is deformed under the action of stress, the correction steel plate 2 is not affected and always maintains a stress-free state; but when the ambient temperature changes, the stressed steel plate 1 and the correction steel plate 2 shrink and stretch synchronously, and the deformation of the correction steel plate 2 is always consistent with that of the stressed steel plate 1; then, ultrasonic emission points and ultrasonic receiving points are set on the surfaces of the stressed steel plate 1 and the correction steel plate 2 in parallel with the force direction and at the same interval l; synchronously measure t0+△t t and t0+△t+△t t ; Then, based on the above theory, the influence of temperature is eliminated to obtain the accurate stress value. It is highly practical, simple in structure, economical, and harmless to the structure. It can be widely promoted and applied to the correction of temperature influence generated in stress testing of existing and newly built steel structures.

[0024] Among them, the stress-bearing steel plate 1 is the stress-bearing structural steel plate of the existing structure and the newly built structure. The correction steel plate 2 is a zero stress state steel plate that eliminates the temperature effect. Stress is the unit area force generated on the steel plate after the component is stressed. The temperature change is the temperature difference caused by the change in air temperature. The ultrasonic transmitter 3 is the starting point of ultrasonic propagation in the steel plate. The ultrasonic receiver 4 is the end point of ultrasonic propagation in the steel plate. The reference wave velocity is the ultrasonic propagation velocity in the steel structure at the reference temperature and zero stress. The wave velocity change caused by stress is the difference between the wave velocity after the stress is generated and the reference wave velocity. The wave velocity change caused by temperature change is the difference between the wave velocity after being affected by the ambient temperature and the reference wave velocity. The propagation distance is the distance between the ultrasonic transmitter 3 and the ultrasonic receiver 4. The reference propagation time is the time for the reference wave velocity to pass through the propagation distance. The propagation time change caused by stress is the difference between the propagation time after the stress is generated and the reference propagation time. The propagation time change caused by temperature is the difference between the propagation time after being affected by the ambient temperature and the reference propagation time.

[0025] See also Figure 1In other embodiments, a fixing bolt is also included. A fixing hole 5 is provided at one end of the correction steel plate 2. One end of the fixing bolt passes through the fixing hole 5 and is threadedly connected to the stress-bearing steel plate 1. In this way, one end of the correction steel plate 2 is fixed to the surface of the stress-bearing steel plate 1. Further, a guide bolt is also included. A long movable hole 6 is provided at one end of the correction steel plate 2 away from the fixing hole 5. The long movable hole 6 is arranged parallel to the stress; one end of the guide bolt passes through the long movable hole 6 and is threadedly connected to the stress-bearing steel plate 1. Through the arrangement of the guide bolt and the long movable hole 6, when the stress of the stress-bearing steel plate 1 changes, the correction steel plate 2 is not affected and is always in a stress-free state, and can guide the deformation of the stress-bearing steel plate 1 and the correction steel plate 2. Further, a plurality of fixing holes 5 and long movable holes 6 are arranged in the width direction of the correction steel plate 2. Through the arrangement of a plurality of fixing holes 5 and long movable holes 6, the correction steel plate 2 can be fixed and guided more conveniently. Specifically, two fixing holes 5 and two long movable holes 6 are arranged in the width direction of the correction steel plate 2, respectively.

[0026] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. An ultrasonic longitudinal wave steel structure stress detection temperature correction device, characterized in that: include: A stress-bearing steel plate, a correction steel plate, an ultrasonic transmitter and an ultrasonic receiver; the stress-bearing steel plate and the correction steel plate are made of the same material; the correction steel plate is stacked on the surface of the stress-bearing steel plate, and one end of the correction steel plate is fixedly connected to the stress-bearing steel plate; both the stress-bearing steel plate and the correction steel plate are equipped with an ultrasonic transmitter and an ultrasonic receiver, and the ultrasonic wave emitted by the ultrasonic transmitter is parallel to the stress on the stress-bearing steel plate; and the spacing between the ultrasonic transmitter and the ultrasonic receiver on the stress-bearing steel plate is the same as the spacing between the ultrasonic transmitter and the ultrasonic receiver on the correction steel plate.

2. The ultrasonic longitudinal wave steel structure stress detection temperature correction device according to claim 1 is characterized in that: It also includes a fixing bolt. A fixing hole is opened at one end of the correction steel plate. One end of the fixing bolt passes through the fixing hole and is threadedly connected to the stress-bearing steel plate.

3. The ultrasonic longitudinal wave steel structure stress detection temperature correction device according to claim 2 is characterized in that: It also includes a guide bolt. A long movable hole is opened at one end of the correction steel plate away from the fixing hole. The long movable hole is arranged parallel to the stress. One end of the guide bolt passes through the long movable hole and is threadedly connected to the stressed steel plate.

4. The ultrasonic longitudinal wave steel structure stress detection temperature correction device according to claim 3 is characterized in that: A plurality of the fixed holes and the long movable holes are arranged in the width direction of the correction steel plate.

5. The ultrasonic longitudinal wave steel structure stress detection temperature correction device according to claim 1 is characterized in that: The width of the stress-bearing steel plate is greater than the width of the correction steel plate.

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