Pulse excitation device for structure test

Abstract

The invention discloses a pulse excitation device for structure testing, and relates to the technical field of bridge engineering detection, the pulse excitation device comprises a steel cylinder outer cladding layer, a flange plate and a damping cushion layer, the damping cushion layer is connected with the flange plate through a bolt, and the flange plate is welded with the steel cylinder outer cladding layer. According to the pulse excitation device for the structure test, the explosive is detonated through the blasting fuse, an ideal single pulse load is formed by instantaneous counter-acting force generated when high-pressure gas generated at the moment of explosion of the explosive ejects water at a high speed, and parameters such as the damping ratio, the dynamic impact effect, the natural vibration frequency and the dynamic response of a bridge structure are measured. The shock excitation device does not generate vibration except single impulse force on a bridge structure, the impulse energy is controlled by adjusting the explosive loading amount, the impulse force peak value and the impulse time are controlled by adjusting the water amount and the damping characteristics of the damping cushion layer, and the test accuracy is improved.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering detection, and in particular to a pulse excitation device for structural testing. Background Art

[0002] The dynamic load test of bridges is not only one of the methods to check whether the newly built bridges meet the design bearing capacity standards, but also one of the important means to evaluate the safety of existing bridges. The main test contents include the dynamic response parameters of the bridge structure and the self-vibration characteristic parameters of the bridge structure. The way to obtain these parameters is to make the bridge structure produce artificial vibrations. The commonly used methods to excite bridge vibrations are environmental random excitation method, vehicle excitation method and vehicle jumping excitation method. The environmental random excitation method is suitable for the test of the self-vibration characteristics of large-span bridge structures. The self-vibration characteristics are measured by randomly using the micro-vibration generated by the dynamic loads such as wind load, ground pulse or water flow in the environment. This excitation method is random and accidental, and it is not easy to control the variables artificially. The vehicle excitation method obtains the dynamic response and self-vibration characteristics of the structure by collecting and analyzing the aftershock signals after the vehicle passes; the vehicle jumping test makes the rear wheels of a single car fall naturally from a certain height pad, thereby exciting the bridge vibration. The latter two excitation methods are easy to produce complex and redundant vibrations on the bridge structure outside the measuring point, output redundant vibration signals, and affect the accuracy of the data.

[0003] In order to obtain more accurate dynamic characteristics of the bridge, ensuring that the bridge is subjected to single pulse excitation is an ideal excitation method in dynamic load tests. Single pulse excitation can quickly stimulate the dynamic response of the bridge, and the test requirements of different bridges can be met by adjusting the magnitude and frequency of the excitation. At present, the method of using an impact hammer can effectively excite smaller span slab bridges and pedestrian bridges, but for many large span bridges with great flexibility, such as cable-stayed bridges and suspension bridges, bulky excitation equipment is required, which is obviously not suitable for dynamic load tests of large span bridges. Summary of the invention

[0004] The purpose of the present invention is to provide a pulse excitation device for structural testing, which controls the pulse energy by adjusting the charge amount, and controls the pulse force peak value and pulse time by adjusting the water volume and the damping characteristics of the damping pad, so as to solve the problems of traditional excitation devices, better measure the vibration characteristics of bridges, thereby improving the accuracy of test data and providing a reliable judgment basis for bridge safety assessment.

[0005] To achieve the above objectives, the present invention provides a pulse excitation device for structural testing, comprising a steel cylinder outer layer, a flange and a damping pad, wherein the damping pad is connected to the flange by bolts, and the flange is welded to the steel cylinder outer layer.

[0006] Preferably, a water box and an object box are provided in the outer covering of the steel cylinder, the object box is provided on the upper part of the water box, and water is provided in the water box.

[0007] Preferably, explosives are arranged in the storage box, the detonator on the explosives is connected to the fuse, the fuse passes through the lead hole, and the lead hole is arranged on the lower left side of the outer sheath of the steel cylinder.

[0008] Preferably, ten bolts are provided, and the ten bolts are distributed circumferentially along the flange, and the flange is made of carbon steel.

[0009] Preferably, the bottom of the bolt is connected to the drill hole, and the drill hole is provided with anchor glue.

[0010] Preferably, the damping pad layer is made of any one of rubber, ACF material, and EPDM damping substrate.

[0011] Preferably, the explosive is selected from one of nitroglycerin explosive and water gel explosive.

[0012] Therefore, the present invention adopts the above-mentioned pulse excitation device for structural testing, and utilizes the instantaneous reaction force generated by the high-pressure gas generated at the moment of the explosion of the explosives to spray water at high speed, thereby forming an ideal single pulse load, and achieving effective impact on the dynamic load test measuring point of the bridge. Compared with the traditional excitation device, the present invention is easier to control variables artificially, and the pulse energy can be controlled by adjusting the amount of explosives, the pulse energy can be controlled by adjusting the charge amount, and the pulse force peak and pulse time can be controlled by adjusting the water amount and the damping characteristics of the damping pad. The water scattered after the explosion of the present invention will not cause harm to the human body, and it has the advantages of being safe and harmless, and it is simple to assemble and can be applied to different types of bridges.

[0013] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of an embodiment of a pulse excitation device for structural testing of the present invention; Figure 2 This is a schematic diagram of the steel cylinder-flange structure of the present invention; Figure 3 A top view of the device of the present invention; Reference numerals 1. Outer layer of steel cylinder; 2. Flange; 3. Bolts; 4. Water box; 5. Storage box; 6. Water; 7. Fuse; 8. Lead hole; 9. Explosives; 10. Damping pad; 11. Rebar glue. DETAILED DESCRIPTION

[0015] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0016] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0017] Example See also Figure 1-3 The present invention provides a pulse excitation device for structural testing, including a steel cylinder outer layer 1, a flange 2 and a damping pad 10, the damping pad 10 is connected to the flange 2 by bolts 3, the damping pad 10 is made of rubber, ACF material, EPDM damping base material, etc., and the flange 2 is welded to the steel cylinder outer layer 1.

[0018] A water box 4 and a storage box 5 are arranged inside the outer layer 1 of the steel cylinder. Both the water box 4 and the storage box 5 are made of pp plastic. The storage box 5 is arranged on the upper part of the water box 4. Water 6 is arranged inside the water box 4. Explosives 9 are arranged inside the storage box 5. The amount of explosives 9 can be adjusted according to the characteristics of the bridge. Explosives 9 can be selected from nitroglycerin explosives, water gel explosives, etc. The detonator on the explosives 9 is connected to the fuse 7. The setting of the fuse 7 is convenient for ensuring the safety of the test personnel. The fuse 7 passes through the lead hole 8. The lead hole 8 is arranged on the lower left side of the outer layer 1 of the steel cylinder. The lead hole 8 runs from the lower left side of the outer diameter of the steel cylinder to the inner diameter. The high-pressure gas generated at the moment of the explosion of the explosive 9 is used to spray the water at high speed to generate the instantaneous reaction force, forming an ideal single pulse load, so as to achieve effective impact on the dynamic load test measuring point of the bridge. Ten bolts 3 are provided, and the ten bolts 3 are distributed in a circle along the flange 2, and the material of the flange 2 is carbon steel. The bolts 3 connect the flange 2 and the damping pad 10, and the bottom of the bolts 3 is connected to the drill hole, and the anchor glue 11 is provided in the drill hole.

[0019] The specific method is as follows: the bottom of the outer layer 1 of the steel cylinder is welded to the flange 2 as a whole. Drill holes on the bridge surface at the dynamic load test measurement point, and after injecting enough rebar glue 11, each hole position is aligned with the damping pad 10 and the steel cylinder containing the flange 2 in turn. Insert the bolts 3 into the aligned underground boreholes in sequence. Before loading the test material, the tester determines the charge amount according to the characteristics of the bridge and the dynamic load test to adjust the control pulse energy, determine the amount of water, and adjust the damping characteristics of the damping pad 10 to control the pulse force peak and pulse time. After the storage box 5 is aligned with the lead hole 8 of the steel cylinder, the fuse 7 connected to the detonator is passed through, and then the explosives 9 are filled into the lower storage box 5. After the explosive storage box 5 is sealed, an upper sealed water box 4 containing a certain amount of water is placed on it. After the rebar glue 11 of the underground borehole reaches the ideal strength, the ignition tester ignites the fuse 7 at the far end of the safe distance, detonates the detonator, and then detonates the explosives 9. The instantaneous reaction force generated by the high-pressure gas generated by the explosion of the explosive 9 ejects the water at high speed, forming an ideal single pulse load, which produces a vibration effect on the bridge at the measuring point. At the same time, the damping pad 10 on the bridge deck effectively prevents the steel cylinder from rebounding.

[0020] Therefore, the present invention adopts the above-mentioned pulse excitation device for structural testing, which can be applied to different types of bridges. While ensuring the safety and harmlessness of the test, it aims to form an ideal single pulse excitation, and effectively control the pulse energy, pulse force peak and pulse time, solving the problem of bridge vibration outside the measuring point after other excitation devices work, and obtaining a high-quality vibration signal of the bridge at the measuring point, thereby improving the overall work efficiency; it is easier to artificially control variables than traditional excitation devices, and the pulse energy can be controlled by adjusting the amount of explosives, the pulse energy can be controlled by adjusting the charge amount, and the pulse force peak and pulse time can be controlled by adjusting the water amount and the damping characteristics of the damping pad layer; the water sprayed and scattered after the explosion of the present invention will not cause harm to the human body, and it has the advantages of safety and harmlessness, and the assembly is simple and can be applied to different types of bridges.

[0021] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A pulse excitation device for structural testing, characterized in that: It comprises a steel cylinder outer layer, a flange and a damping pad. The damping pad is connected to the flange through bolts, and the flange is welded to the steel cylinder outer layer.

2. The pulse excitation device for structural testing according to claim 1, characterized in that: A water box and an article box are arranged in the outer covering layer of the steel cylinder. The article box is arranged on the upper part of the water box. Water is arranged in the water box.

3. The pulse excitation device for structural testing according to claim 2, characterized in that: Explosives are arranged in the storage box, and the detonator on the explosives is connected with a fuse, and the fuse passes through a lead hole, and the lead hole is arranged on the lower left side of the outer sheath of the steel cylinder.

4. The pulse excitation device for structural testing according to claim 3, characterized in that: There are ten bolts, which are distributed circumferentially along the flange, and the flange is made of carbon steel.

5. The pulse excitation device for structural testing according to claim 4, characterized in that: The bottom of the bolt is connected to the drill hole, and the drill hole is provided with a reinforcing bar glue.

6. The pulse excitation device for structural testing according to claim 5, characterized in that: The damping pad layer is made of any one of rubber, ACF material and EPDM damping substrate.

7. The pulse excitation device for structural testing according to claim 6, characterized in that: The explosive is selected from one of nitroglycerin explosive and water gel explosive.

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