A pulse excitation device for structural testing

Abstract

The present invention discloses a pulse excitation device for structural testing, which relates to the technical field of bridge engineering inspection, and includes a steel cylinder outer layer, a flange and a damping pad. The damping pad is connected to the flange by bolts, and the flange is welded to the steel cylinder outer layer. The present invention adopts the above-mentioned pulse excitation device for structural testing, detonates explosives through a fuse, and the high-pressure gas generated at the moment of the explosion of the explosives sprays water at high speed to generate an instantaneous reaction force, forming an ideal single pulse load, and measuring parameters such as the damping ratio, dynamic impact effect, natural frequency and dynamic response of the bridge structure. The excitation device does not generate vibrations other than the single pulse force on the bridge structure, controls the pulse energy by adjusting the charge amount, controls the pulse force peak and pulse time by adjusting the water amount and the damping characteristics of the damping pad, and improves the test accuracy.

Description

Technical Field

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

[0002] Bridge dynamic load testing is not only a method for verifying whether newly built bridges meet their design bearing capacity standards, but also an important means of assessing the safety of existing bridges. The main test contents include the dynamic response parameters and natural vibration characteristics of the bridge structure. These parameters are obtained by inducing artificial vibration in the bridge structure. Common methods for stimulating bridge vibration include environmental random excitation, vehicle excitation, and vehicle-jumping excitation. The environmental random excitation method is suitable for testing the natural vibration characteristics of long-span bridge structures. It measures the natural vibration characteristics by randomly applying microvibrations generated by dynamic loads such as wind loads, ground ripples, or water flow. This excitation method is random and contingent, making it difficult to control variables. The vehicle-jumping excitation method collects and analyzes aftershock signals from a vehicle passing by to determine the dynamic response and natural vibration characteristics of the structure. The vehicle-jumping test involves the rear wheels of a single vehicle dropping naturally from blocks at a certain height, thereby inducing bridge vibration. The latter two excitation methods are prone to generating complex and redundant vibrations in the bridge structure outside the measurement point, outputting redundant vibration signals and affecting data accuracy.

[0003] To obtain more accurate dynamic characteristics of a bridge, ensuring that the bridge is subjected to single-pulse excitation is the ideal excitation method for dynamic load testing. Single-pulse excitation can rapidly stimulate the bridge's dynamic response, and the excitation magnitude and frequency can be adjusted to meet the testing requirements of different bridges. Currently, the use of impact hammers is very effective for excitation of smaller-span slab bridges and pedestrian overpasses. However, for many long-span bridges with high flexibility, such as cable-stayed and suspension bridges, bulky excitation equipment is required, making it unsuitable for dynamic load testing 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 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 item box are provided in the outer covering of the steel cylinder, the item 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 anchor glue is provided in the drill hole.

[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 eject 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 traditional excitation devices, the present invention is easier to control variables manually. 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 amount of water and the damping characteristics of the damping pad. The water sprayed and scattered after the explosion of the present invention will not cause harm to the human body, and has the advantages of being safe and harmless. It is also 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 This is a schematic structural diagram of an embodiment of a pulse excitation device for structural testing according to the present invention;

[0015] Figure 2 This is a schematic diagram of the steel cylinder-flange structure of the present invention;

[0016] Figure 3 A top view of the device of the present invention;

[0017] Reference numerals

[0018] 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. Anchor glue. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0020] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "first", "second" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" 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 object being described changes, the relative positional relationship may also change accordingly.

[0021] Example

[0022] 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. The flange 2 is welded to the steel cylinder outer layer 1.

[0023] A water box 4 and a storage box 5 are provided 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 provided on the upper part of the water box 4. Water 6 is provided in the water box 4. Explosives 9 are provided in 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 provided on the lower left side of the outer layer 1 of the steel cylinder. The lead hole 8 passes through from the lower left side of the outer diameter of the steel cylinder to the inner diameter. The instantaneous reaction force generated by the high-pressure gas generated at the moment of the explosion of the explosives 9 is used to spray water at high speed to form an ideal single pulse load, thereby achieving an effective impact on the dynamic load test measuring point of the bridge.

[0024] Ten bolts 3 are provided, and the ten bolts 3 are distributed along the circumference of the flange 2. The flange 2 is made of carbon steel. The bolts 3 connect the flange 2 and the damping pad 10. The bottom of the bolts 3 is connected to the drill hole, and the drill hole is provided with a steel bar glue 11.

[0025] The specific method is as follows: the bottom of the steel cylinder outer sheath 1 is welded to the flange 2 to form a single piece. A hole is drilled on the bridge surface at the dynamic load test measurement point. After sufficient anchoring glue 11 is injected, each hole is aligned with the damping pad 10 and the steel cylinder containing the flange 2. Bolts 3 are then inserted into the aligned underground boreholes. Before loading the test material, the tester determines the charge amount based on the characteristics of the bridge and the dynamic load test to adjust and control the pulse energy. The water volume and the damping properties of the damping pad 10 are also adjusted to control the peak pulse force and pulse duration. After the storage box 5 is aligned with the lead hole 8 of the steel cylinder, the fuse 7, which is connected to the detonator, is threaded through and the explosives 9 are then filled into the lower storage box 5. After the explosives storage box 5 is sealed, an upper sealed water box 4 containing a predetermined amount of water is placed on top. Once the anchoring glue 11 in the underground borehole reaches the desired strength, the ignition tester ignites the fuse 7 from a safe distance, detonating the detonator and then the explosives 9. The instantaneous reaction force generated by the high-pressure gas generated at the moment of 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.

[0026] 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. It solves the problem of bridge vibration outside the measuring point after other excitation devices are working, obtains high-quality vibration signals of the bridge at the measuring point, and improves overall work efficiency. Compared with traditional excitation devices, it is easier to control variables manually. 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 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. It is simple to assemble and can be applied to different types of bridges.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. 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 solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A pulse excitation device for structural testing, characterized by: It includes 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; A water box and an item box are provided in the outer layer of the steel cylinder, the item box is provided on the upper part of the water box, and water is provided in the water box; Explosives are arranged in the storage box. The detonator on the explosives is connected to the fuse. The fuse passes through the lead hole. The lead hole is arranged on the lower left side of the outer sheath of the steel cylinder.

2. The pulse excitation device for structural testing according to claim 1, characterized in that: There are ten bolts provided, and the ten bolts are distributed circumferentially along the flange, and the flange is made of carbon steel.

3. The pulse excitation device for structural testing according to claim 2, characterized in that: The bottom of the bolt is connected to the drill hole, and the drill hole is provided with anchor glue.

4. The pulse excitation device for structural testing according to claim 3, characterized in that: The damping pad layer is made of any one of rubber, ACF material, and EPDM damping base material.

5. The pulse excitation device for structural testing according to claim 4, characterized in that: The explosive is selected from one of nitroglycerin explosive and water gel explosive.

Images