Falling stone impact structure simulation test system for vibration table test

Abstract

The invention belongs to the technical field of earthquake disaster simulation, and discloses a rockfall impact structure simulation test system for a vibration table test, which comprises a rack, a vibration table arranged on the horizontal ground, and the rack is fixedly arranged on the table surface of the vibration table; the test model is fixedly arranged on the table surface of the vibration table; the limiting assembly comprises a guide groove, the guide groove is obliquely formed in the rack, and a low-end outlet of the guide groove faces the test model; the impact test piece is arranged in the guide groove; according to the scheme, the guide groove is obliquely arranged, and the impact test piece is arranged in the guide groove, so that the impact test piece slides down along the guide groove and impacts a preset part of the test model in an earthquake environment simulated by the vibration table, and the problems that a motion path of rockfall is random due to lack of track guidance and the rockfall is easy to deviate from a target structure during dynamic loading of the vibration table are avoided; the problem that an existing experimental device is lack of rockfall limiting is solved.

Description

TECHNICAL FIELD

[0001] The present scheme belongs to the technical field of earthquake disaster simulation, and particularly relates to a rockfall impact structure simulation test system for shaking table test. BACKGROUND

[0002] When an earthquake occurs, the vibration will break the original balance of the mountain, causing the rocks on the mountain to collapse along the original fissure and roll down under the action of gravity, thereby producing rockfall. For structures such as power transmission towers, bridge piers, and houses distributed in earthquake-prone areas, the impact force of rockfall can easily cause the tower body to tilt and collapse; the bridge pier is impacted, affecting the stability of the bridge, and in severe cases, causing collapse; the house is hit by rockfall, causing wall damage and house collapse. Therefore, through rockfall simulation test, the stress and strain distribution of each part of the structure when rockfall of different mass and speed impacts the structure such as power transmission tower, bridge pier, and house is analyzed, so as to set a reasonable position of rockfall net, buffer device, etc., to resist rockfall impact of structures in earthquake-prone areas and reduce the loss caused by earthquake rockfall disaster.

[0003] For example, see the document with the existing publication (announcement) number CN115389151A, which discloses a dangerous rock mass rockfall impact simulation test device, including a hillside simulation piece and an impact test mechanism. The impact test mechanism includes a first bottom plate, a second bottom plate, a first hydraulic cylinder, a side plate, a fixed plate, an elastic plate piece, a gravity sensor, a digital instrument, and a camera. The first bottom plate is arranged on one side of the hillside simulation piece, and the second bottom plate is arranged above the first bottom plate. The simulated rockfall impacts the elastic plate piece, the gravity sensor displays the impact force received through the digital instrument, and the camera records the display data on the digital instrument. The maximum digital value captured by the camera is the maximum impact force caused by the rockfall simulation. Finally, the actual rockfall impact data can be obtained.

[0004] The above simulation test device, when tested, releases the rockfall on the slope plate, but the slope plate lacks constraint on the motion trajectory of the rockfall, resulting in strong randomness of the motion path, changing the acceleration and final impact speed of the rockfall, and further causing fluctuations in the impact force. When tested in a shaking table loading environment, the test table is in a dynamic motion state, and the rockfall is easy to deviate from the target structure, resulting in uncertain impact position, deviation from the key force component, and even problems such as simulation rockfall rolling out of the test area, impacting equipment, or threatening test safety. SUMMARY

[0005] The purpose of the present scheme is to provide a rockfall impact structure simulation test system for shaking table test, to solve the problem of lack of rockfall limiting in the existing experimental device.

[0006] In order to achieve the above object, the present scheme provides a rockfall impact structure simulation test system for shaking table test, comprising a rack, further comprising: a shaking table, which is arranged on a horizontal ground, and the rack is fixedly arranged on the table top of the shaking table; a test model, which is fixedly arranged on the table top of the shaking table; a limiting assembly, which comprises a guide groove, the guide groove is obliquely arranged on the rack, and the low-end outlet of the guide groove faces the test model; an impact test piece, which is arranged in the guide groove.

[0007] The principle of the present scheme is that the guide groove is obliquely arranged, then the impact test piece (such as a steel ball) is placed in the guide groove, and the impact test piece is made to slide along the guide groove and impact the preset part of the test model (such as a power transmission tower or a pier) at a set angle from the low-end outlet under the simulated seismic environment of the shaking table, so as to test the stress and strain distribution of the impact position.

[0008] The effect of the present scheme is that (1) the effective limiting of the impact test piece by the guide groove solves the problems of random movement path of the rockfall, easy deviation from the target structure during dynamic loading of the shaking table, and unstable impact point of different specifications of test pieces in the existing device, so that the consistency of the impact position and the repeatability of the test are ensured, the center of gravity of the impact test piece (simulated rockfall) is always consistent with the center line of the track during the falling process, so that the same target position of the structure is always impacted by the impact test piece (simulated rockfall) with varying movement path, the consistency of the test variables is ensured, and the comparability of the structure dynamic response data and the scientificity of the test results are improved; (2) the present scheme can control the falling track of the simulated rockfall under the dynamic loading condition of the shaking table, prevent the rockfall from deviating, derailing or rolling out of the table top due to platform vibration, ensure that the rockfall can stably and orderly impact the target structure, and improve the repeatability and safety of the test.

[0009] Further, the guide groove is a groove structure with an open top and through both ends, the guide groove comprises a bottom plate, side plates and movable plates, the bottom surface of the bottom plate is obliquely arranged on the rack, a plurality of groups of threaded holes are arranged on the bottom plate along the width direction of the bottom plate, the number of the side plates and the movable plates is both two, the two side plates are symmetrically fixed to the two sides of the bottom plate through the threaded holes, and the opposite surfaces of the two side plates are both provided with insertion grooves arranged along the height direction, and the side walls of the two movable plates are respectively inserted into the insertion grooves to form the guide groove.

[0010] The principle and effect of the scheme are that: (1) the guide groove is designed as a groove structure with an open top and through ends, a guide space is formed by the symmetrical side plates fixed on both sides of the bottom plate and the movable plates inserted into the side plate slots, the side plates can be adjusted in horizontal distance along the screw holes of the bottom plate, and the movable plates can be adjusted in height through the slots to adapt to impact test pieces (such as steel balls) of different diameters, so as to ensure that the center of gravity is consistent with the center line of the guide groove; meanwhile, the bottom plate is inclinedly arranged on the rack, and the vibration table simulates the earthquake environment, so that the impact test piece stably slides along the guide groove and directionally impacts the preset position of the test model. (2) The combination of the side plates and the movable plates solves the problems that the falling rock movement path is random in the existing device and the vibration table is easy to deviate from the target during dynamic loading, and the size of the guide groove can be flexibly adjusted through the screw holes and the slots to adapt to the constant impact point of impact test pieces of different specifications, so as to avoid the interference of test variables caused by the size change of the impact test piece.

[0011] Further, the limiting assembly further comprises a servo electric cylinder and a limiting pipe, the servo electric cylinder is inclinedly arranged on the rack, the free end of the telescopic rod of the servo electric cylinder is fixedly connected with one end of the limiting pipe, the bottom plate and the movable plate are both provided with a through slot for the limiting pipe to pass through, and the limiting pipe is used for limiting the sliding of the impact test piece.

[0012] The principle and effect of the scheme are that: the servo electric cylinder drives the limiting pipe to be inclined, the limiting pipe passes through the through slots of the bottom plate and the movable plate to abut against the impact test piece, so as to limit the unintended sliding of the impact test piece caused by the loading of the vibration table; at a preset time, the servo electric cylinder is retracted to drive the limiting pipe to release the impact test piece, so that the impact test piece slides along the guide groove and impacts the test model.

[0013] Further, the limiting assembly further comprises three groups of limiting rods, two groups of which are vertically and symmetrically arranged on the bottom plate and located at the rear end of the impact test piece, and the free end of each limiting rod is connected with a horizontally arranged limiting rod; the side plate is provided with a through hole for the horizontally arranged limiting rod to pass through.

[0014] The principle and effect of the scheme are that: the three groups of limiting rods limit the rear end of the impact test piece, and the horizontally arranged limiting rods transversely block the impact test piece, so as to avoid the impact test piece from sliding out of the top end of the guide groove at the initial stage of the loading of the vibration table.

[0015] Further, a plurality of groups of universal steel ball rollers are symmetrically arranged on the rack, and the limiting pipe and the universal steel ball rollers are in sliding connection.

[0016] The principle and effect of the scheme are that: the rolling of the universal steel ball rollers provides low-friction support for the telescopic movement of the limiting pipe, so that the servo electric cylinder can move along the preset track when driving the limiting pipe to retreat or abut against the impact test piece.

[0017] Further, a high-speed camera is fixed on the vibration table and faces the low end outlet of the guide groove.

[0018] The principle and effect of the present application are that the high-speed camera is used to record the motion state of the impact test piece during the impact process, and the instantaneous speed before the impact test model is calculated by matching the shooting frequency Further, a recovery bucket is fixed on the vibration table, and a buffer is arranged in the recovery bucket, and the bucket opening of the recovery bucket is located below the low end outlet of the guide groove.

[0019] The principle and effect of the present application are that the impact test piece is recovered to prevent secondary damage to the vibration table or rolling out of the test area, and the test safety is ensured; and the buffer is used to absorb the residual kinetic energy after impact.

[0020] Further, the vibration table is fixed on the concrete base by bolts.

[0021] The principle and effect of the present application are that the vibration table is rigidly connected with the base to avoid energy loss.

[0022] Further, the impact test piece is a steel ball, a rockfall or a concrete block.

[0023] The principle and effect of the present application are that test pieces of different materials, shapes and masses can be selected to simulate rocks with different characteristics in nature (such as different impact forces caused by density differences, different impact effects caused by irregular shapes, etc.) Further, the test model is a power transmission tower, a bridge pier, a house or a retaining wall.

[0024] The principle and effect of the present application are that various structures susceptible to rockfall impact in earthquake-prone areas are selected as impact objects to simulate the scenario in which various structures encounter rockfall impact induced by earthquakes in actual disasters. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 FIG. 1 is a structural schematic diagram of a rockfall impact structure simulation test system for a vibration table test according to the present application; Figure 2 FIG. 2 is a structural schematic diagram of a guide groove according to the present application; Figure 1 Figure 3 FIG. 3 is a structural schematic diagram of a guide groove according to the present application; Figure 2 Figure 4 FIG. 4 is a structural schematic diagram of a guide groove and a rack according to the present application; Figure 5 FIG. 5 is a structural schematic diagram of an impact position according to the present application; Figure 6 FIG. 6 is a structural schematic diagram of a measurement assembly according to the present application. ​​

[0026] The reference signs in the drawings of the specification include: rack 1, bearing steel pipe 11, support steel pipe 12, vibration table 2, test model 3, concrete pier 31, limiting assembly 4, guide groove 41, bottom plate 411, side plate 412, movable plate 413, insertion groove 414, through groove 415, through hole 416, servo electric cylinder 42, limiting pipe 43, limiting rod 44, universal steel ball 45, impact test piece 5, high-speed camera 6, balance magnet 62, recovery barrel 7, measuring assembly 8, first magnet 81, second magnet 82, support rod 83, magnetic separation plate 84, infrared sensor 85. DETAILED DESCRIPTION

[0027] The concept and the generated technical effects of the present application will be described below in conjunction with the embodiments to make a clear and complete description, so as to fully understand the purpose, features and effects of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments, and other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative labor are within the scope of protection of the present application: Embodiment one: Please refer to Figure 1 The present embodiment provides a rockfall impact structure simulation test system for vibration table test, which mainly consists of rack 1, vibration table 2, test model 3, limiting assembly 4, impact test piece 5, high-speed camera 6 and recovery barrel 7. The vibration table 2 is fixed on the concrete base through foundation bolts as the bearing basis of the whole system, and the vibration sources can be arranged around the vibration table 2 to apply artificial or measured seismic wave to simulate seismic vibration loading. A plurality of evenly distributed anchor holes are provided on the table surface of the vibration table 2, and the rack 1 can be detachably fixed on the table surface of the vibration table 2 through anchor rods and anchor cables to provide support for the limiting assembly 4. The test model 3 can be selected from power transmission tower, bridge pier, house or retaining wall, etc. as needed, and in the present embodiment, a 1:10 scale power transmission tower model is taken as an example, and steel balls with diameters of 9.6 cm, 14.6 cm and 19.6 cm are selected as impact test pieces 5 to study various conditions under rockfall impact; the power transmission tower is fixed on the vibration table 2 through steel pads fixed on two legs of the power transmission tower, so that it is detachably fixed on the vibration table 2, and the other two legs of the power transmission tower are fixed on the concrete pier 31 and fixed on the top surface of the concrete pier 31 through bolts and gaskets, and the concrete pier 31 can simulate uneven terrain to make the test model 3 more consistent with the terrain conditions in the actual engineering scene.

[0028] The high-speed camera 6 is fixed on the side of the table surface of the vibration table 2 by a tripod, and the lens thereof faces the low-end outlet of the guide groove 41, the shooting frame rate is set to 1000 frames / s, the motion state of the impact test piece 5 before impacting the test model 3 can be recorded, and the instantaneous speed and trajectory parameters of the steel ball can be calculated through image processing. The recovery barrel 7 is also fixed on the table surface of the vibration table 2, the barrel bottom is fixedly connected with the table surface of the vibration table 2, and the barrel opening is located directly below the low-end outlet of the guide groove 41, and the barrel is filled with foam or fine sand as a buffer. When the impact test piece 5 impacts the test model 3, the recovery barrel 7 can receive the test piece and absorb the residual kinetic energy of the test piece through the buffer, prevent the test piece from rebounding or rolling to the edge of the vibration table 2, avoid secondary damage to the equipment, and ensure the safety of the test.

[0029] Please refer to Figure 1 and Figure 4 The rack 1 is a fixed rack 1 composed of a plurality of square steel pipes welded together, and the rack 1 is used to provide stable support for the limiting assembly 4 and the angle track inclination angle function. A group of inclined load-bearing steel pipes 11 and a group of inclined support steel pipes 12 are symmetrically arranged in the rack 1, and the angle can be preset and determined according to the needs before the test, and used to adjust the arrangement angle of the limiting assembly 4 relative to the horizontal plane. In the embodiment, the limiting assembly 4 is arranged on the load-bearing steel pipe 11 of the rack 1, forming a 45° inclination angle, sliding along the inclined track and impacting the target structure, realizing the simulation of rockfall impact under a typical impact angle. The angle can also be flexibly adjusted according to the research needs, for analyzing the change law of the structural response under different impact angles.

[0030] Please refer to Figures 2-4 The limiting assembly 4 includes a guide groove 41, a servo electric cylinder 42, a limiting pipe 43, a limiting rod 44 and a universal steel ball 45. The guide groove 41 is inclinedly arranged on the rack 1, and the low-end outlet thereof faces the test model 3, and is used to constrain the motion trajectory of the impact test piece 5. The guide groove 41 is a groove structure with an open top and through both ends, which is surrounded by a bottom plate 411, a side plate 412 and a movable plate 413. The bottom surface of the bottom plate 411 is fixed with the rack 1, and a plurality of groups of threaded holes are arranged on the bottom plate 411 in the width direction, and the distance between each group of threaded holes is 5 cm, and a total of 2 groups (such as Figure 2The side plates 412 are fixed on the bottom plate 411 by bolts, and the fixed positions of the side plates 412 can be adjusted flexibly. By selecting different sets of threaded holes, the distance between the two side plates 412 can be adjusted to adapt to steel balls with diameters of 5-20 cm. The opposite surfaces of the two side plates 412 are provided with insertion grooves 414, which are arranged in the height direction of the side plates 412 and extend to the ends of the side plates 412 in the length direction. The distance between adjacent insertion grooves 414 is gradually increased, and there are two groups of insertion grooves 414, one at the upper end and the other at the lower end of the side wall of the side plate 412. Each group has five insertion grooves 414. The movable plates 413 are inserted into the insertion grooves 414 at the upper and lower ends, respectively. By selecting different heights of the insertion grooves 414, the installation height of the movable plates 413 can be adjusted. In this way, when the impact test piece 5 is a steel ball, a rock or a concrete block with different diameters, the center of gravity of the impact test piece 5 can be kept coincident with the center line of the guide groove 41 by adjusting the distance between the side plates 412 and the height of the movable plates 413, so as to ensure that the impact test piece 5 hits the test model 3 at a constant position, avoiding the displacement of the impact point due to the change of the size of the test piece, and ensuring the uniformity of the test variables.

[0031] Please continue to refer to Figures 2-4 The servo motor cylinder 42 is fixed on the support steel pipe 12 of the rack 1, and is electrically connected with a servo controller. The free end of the telescopic rod is welded and fixed to one end of the limiting pipe 43. The bottom plate 411 and the movable plate 413 are provided with through grooves 415, and the cross-sectional size of the through grooves 415 is adapted to the limiting pipe 43. The end of the limiting pipe 43 away from the servo motor cylinder 42 penetrates through the through groove 415 and extends into the guide groove 41, and is used to resist the impact test piece 5 in the initial stage of the test to limit the unintended sliding of the impact test piece 5 due to the loading of the vibration table 2. When the vibration table 2 is loaded to a preset earthquake stage (such as the peak value of the main shock), the servo controller controls the servo motor cylinder 42 to drive the telescopic rod to retract, and drives the limiting pipe 43 to move away along the through groove 415, releases the impact test piece 5 to slide along the guide groove 41, and realizes the time sequence coupling simulation of the earthquake-rock impact. The rack 1 is also provided with four groups of universal steel ball rollers 45 (as shown in Figure 4 The limiting pipe 43 is in rolling contact with the universal steel ball rollers 45 to reduce the friction resistance of the limiting pipe 43 when it is retracted, and to avoid affecting the release time of the steel ball due to jamming. The limiting assembly 4 further includes three groups of limiting rods 44 matched with the limiting pipe 43, two of which are perpendicular and fixed on the bottom plate 411 at the rear end of the impact test piece 5, and the top ends of the limiting rods 44 are welded with horizontally arranged limiting rods 44. The side plate 412 is provided with a through hole 416 corresponding to the horizontally arranged limiting rod 44. The vertical limiting rod 44 can block the impact test piece 5 from the rear end, and the horizontal limiting rod 44 can limit the lateral displacement of the impact test piece 5. The two can effectively prevent the impact test piece 5 from sliding out of the guide groove 41 at the top end in the initial stage of the loading of the vibration table 2, and improve the safety of the test.

[0032] Specific workflow: Before the test, the steel ball is placed in the guide groove 41, and the guide groove 41 is adjusted according to the size (such as the diameter) of the steel ball; the distance between the two side plates 412 is adjusted through the threaded holes on the bottom plate 411 to adapt to the diameter of the steel ball; the two movable plates 413 are inserted into the corresponding height insertion slots 414 on the opposite surface of the side plate 412, to ensure that the center of gravity of the impact test piece 5 coincides with the center line of the guide groove 41, and the impact position is constant. At this time, the servo controller controls the extension rod of the servo electric cylinder 42 to drive the limiting tube 43 to pass through the through slot 415 of the bottom plate 411 and the movable plate 413, and abut against the front end of the steel ball; among the three groups of limiting rods 44, the horizontal limiting rod 44 at the top end forms a constraint from the rear end and the transverse to the impact test piece 5, preventing it from sliding too early. The power transmission tower is fixed to the table surface of the vibration table 2 through the concrete pier 31, so that it is in the preset impact direction of the low end outlet of the guide groove 41; the high-speed camera 6 is aligned with the low end outlet of the guide groove 41, and the recovery barrel 7 is placed below the outlet. When the test starts, the vibration table 2 starts to apply seismic waves to simulate the earthquake environment, and the rack 1 moves synchronously with the vibration table 2. When the vibration table 2 is loaded to the preset stage (such as the main shock peak time), the servo electric cylinder 42 starts to operate, and the extension rod retracts to drive the limiting tube 43 to slide along the universal steel ball 45, and withdraws from the guide groove 41 to release the constraint on the front end of the steel ball. The steel ball slides down along the inclined guide groove 41 under the action of gravity, and the side plate 412 and the movable plate 413 limit its trajectory, so that it always moves along the preset path. During the sliding process, the high-speed camera 6 records the movement state of the impact test piece 5, which is used to calculate the instantaneous speed before impact. The impact test piece 5 flies out of the low end outlet of the guide groove 41 and impacts the preset part of the test model 3, simulating the impact of rockfall. After impact, the impact test piece 5 falls into the recovery barrel 7, and the fine sand in the barrel absorbs the remaining kinetic energy to prevent it from bouncing or rolling, so as to realize precise simulation under the action of earthquake-rockfall coupling and ensure the controllability and repeatability of the test.

[0033] Example two: Please refer to Figure 5 The difference between the present embodiment and the previous embodiment is that the environment defined in the previous embodiment needs to be in a simulated earthquake environment, so the power transmission tower will inevitably vibrate or sway with the vibration table, and the steel ball will also sway because it is also located on the rack, and the two are more likely to be in a non-same frequency state. At the same time, the steel ball can approach a "point-to-point" impact at the moment of impact with the power transmission tower. This will cause the originally preset static impact point (such as Figure 5The preset impact point is the hinge point of each support of the transmission tower, but since the transmission tower continues to vibrate with the shaking table during the sliding process of the steel ball, and the steel ball also shakes, when the steel ball reaches the preset impact position, the original hinge point has deviated from the position due to vibration, finally resulting in deviation of the actual impact point of the steel ball from the target hinge point. This deviation will cause the steel ball to impact other non-hinge point parts of the transmission tower (for example, the actual impact point is B, C, etc. in the figure), such as the support rod body, and the structural strength and stress characteristics of these parts are different from those of the hinge point, thereby causing the test data to deviate from the dynamic response of the preset key hinge point under impact, deviating from the study of the impact resistance of the key stress part. Secondly, during the sliding process of the steel ball along the guide groove, a gap must be left between the steel ball and the sides of the guide groove (such as Figure 5 The preset impact point is the hinge point of each support of the transmission tower, but since the transmission tower continues to vibrate with the shaking table during the sliding process of the steel ball, and the steel ball also shakes, when the steel ball reaches the preset impact position, the original hinge point has deviated from the position due to vibration, finally resulting in deviation of the actual impact point of the steel ball from the target hinge point. This deviation will cause the steel ball to impact other non-hinge point parts of the transmission tower (for example, the actual impact point is B, C, etc. in the figure), such as the support rod body, and the structural strength and stress characteristics of these parts are different from those of the hinge point, thereby causing the test data to deviate from the dynamic response of the preset key hinge point under impact, deviating from the study of the impact resistance of the key stress part. Secondly, during the sliding process of the steel ball along the guide groove, a gap must be left between the steel ball and the sides of the guide groove (such as

[0034] Please refer to Figure 6 The transmission tower in the embodiment is a light-weight iron tower made of aluminum alloy material and does not have ferromagnetic properties. The impact test piece 5 is a ferromagnetic steel ball. The embodiment also includes a measuring assembly 8, which includes a first magnet 81 arranged behind the impact area of the transmission tower, and the first magnet 81 is connected with a support rod 83, and the end of the support rod 83 is fixedly connected with the transmission tower, so that the transmission tower drives the first magnet 81 to vibrate or shake at the same frequency.

[0035] In this embodiment, the transmission tower to be tested is made of non-ferromagnetic aluminum alloy material, the impact test piece 5 is a ferromagnetic steel ball, and the guide groove 41 is made of magnetic isolation material such as plastic. The first magnet 81 is fixed behind the impact area of the transmission tower, and vibrates or shakes synchronously with the transmission tower; when the ferromagnetic steel ball is impacted out of the outlet end of the guide groove 41, it will be attracted by the first magnet 81. Since the first magnet 81 moves synchronously with the transmission tower, its magnetic force will guide the steel ball to approach the impact area (preset point) where the first magnet 81 is located during the sliding process, offset the trajectory deviation caused by the non-synchronous shaking of the guide groove 41 and the transmission tower, and the deviation caused by the outlet of the guide groove 41, so that the steel ball can keep relative synchronization with the preset point of the transmission tower at the impact moment, thereby impacting the preset impact area, solving the impact point deviation problem caused by the non-synchronous shaking of the two in the previous embodiment.

[0036] Since the attractive force of the first magnet 81 on the ferromagnetic steel ball will generate a component force pointing to the first magnet 81, the speed will increase due to the superposition of the attractive force, resulting in a change in the speed component. Therefore, a second magnet 82 is also included, which has the same magnetism as the first magnet 81 and the same magnetic force, and the second magnet 82 is symmetrically arranged with the first magnet 81 and located in the same horizontal plane. The second magnet 82 is fixedly connected with the support rod 83 through an extension rod (not shown in the figure), so that the second magnet 82 vibrates or shakes synchronously with the first magnet 81. The second magnet 82 is arranged below the outlet of the guide groove 41. By arranging the second magnet 82, the attractive force of the first magnet 81 on the steel ball in the direction of motion of the steel ball is equal in size and opposite in direction, which can be mutually offset to reduce the increase in speed or change in component of the steel ball caused by the attractive force of the first magnet 81; at the same time, the forces of the two in the transverse direction act together to make the steel ball impact the preset point. Since the second magnet 82 is arranged below the outlet of the guide groove 41, a horizontally arranged magnetic isolation plate 84 is arranged at the outlet end of the guide groove 41 to isolate the second magnet 82 from attracting the steel ball at the moment of impact, so that the steel ball directly impacts vertically downward.

[0037] In order to avoid the influence of the vibration table 2 on the high-speed camera 6, the high-speed camera 6 is shaken, and the pictures taken are blurred and distorted. Therefore, the lower portion of the high-speed camera 6 is provided with a support arm 61, and the free end of the support arm 61 is slidably connected with a sliding table. The bottom of the sliding table 85 is provided with a support (not shown in the figure), and the support is arranged on the horizontal ground (in contact with the vibration table 2), so that the high-speed camera 6 will not be shaken. At the same time, since the high-speed camera 6 needs to shoot the moment when the steel ball is hit and impacted, it is necessary to make the high-speed camera 6 as close as possible to the outlet position of the guide groove 41. However, after being close, the impact of the steel ball will produce debris, etc., which may hit the lens of the high-speed camera 6, so it is necessary to protect it. However, in the prior art, a transparent protective glass is generally arranged in front of the lens of the high-speed camera 6. However, in the simulation process, if the object to be measured is a house or a bridge, etc., dust will be generated after impact, thereby covering the protective glass, resulting in the existence of impurities in the taken pictures. Therefore, the protective glass cannot be arranged in front of the high-speed camera 6. In the embodiment, the high-speed camera 6 is arranged below the magnetic isolation plate 84, and the two are not in the same horizontal plane. A set of balance magnets 62 are arranged on the support arm 61 below the high-speed camera 6. The magnetism of the balance magnets 62 is opposite to that of the first magnet 81 and the second magnet 82, and the support arm 61 is located in the middle of the distance between the first magnet 81 and the second magnet 82, so that the balance magnets 62 are attracted to each other by the first magnet 81 and the second magnet 82, and the high-speed camera 6 is balanced in the middle position. When the steel ball hits the preset point of the transmission tower, the first magnet 81 at the rear end of the preset point will move or shake, so that the attraction of the first magnet 81 to the balance magnet 62 is unstable, and the support arm 61 moves on the sliding table under the attraction of the second magnet 82, so that the high-speed camera 6 moves below the magnetic isolation plate 84, thereby avoiding the impact of the debris. It should be noted that, since the first magnet 81 and the second magnet 82 are arranged in the embodiment, although the impact of the steel ball on the preset point can be achieved, the force condition is also affected. Therefore, those skilled in the art can adaptively increase the gravity of the steel ball to reduce the influence of the magnetic force.

[0038] Embodiment three: The difference between the embodiment and the embodiment 2 is that, in order to avoid the influence of the magnetic force after the impact of the steel ball, the first magnet 81 and the second magnet 82 are replaced by electromagnets in the embodiment, and a perspective window is arranged in the guide groove 41, and an infrared sensor 85 is arranged outside the perspective window for detecting the steel ball. The infrared sensor 85 is electrically connected with a controller and has a time delay. When the infrared sensor 85 detects that the steel ball flies out, the first magnet 81 and the second magnet 82 are powered off after 3s, thereby avoiding the influence of the subsequent magnets.

[0039] The above-mentioned are only embodiments of the present application, and the common knowledge of specific structures and characteristics in the scheme is not described too much. It should be pointed out that for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should also be considered as the protection scope of the present application, which will not affect the effect and practicality of the patent. The protection scope claimed in this application should be subject to the content of its claims, and the specific implementation mode and the like recorded in the specification can be used to explain the content of the claims.

Claims

1. A rockfall impact structure simulation test system for a shaking table test, comprising a frame (1), characterized in that, Also include: The vibration table (2) is provided on the horizontal ground, and the rack (1) is fixedly provided on the table surface of the vibration table (2); The test model (3) is fixedly provided on the table surface of the vibration table (2); The limiting component (4) includes a guide groove (41), which is inclinedly arranged on the rack (1), and the low end outlet of the guide groove (41) faces the test model (3); The impact test piece (5) is arranged in the guide groove (41).

2. The rockfall impact structure simulation test system for a shaking table test according to claim 1, characterized in that: The guide groove (41) is a groove structure with an open top and through both ends, and includes a bottom plate (411), a side plate (412) and a movable plate (413). The bottom surface of the bottom plate (411) is inclinedly arranged on the rack (1), and a plurality of sets of threaded holes are arranged on the bottom plate (411) along the width direction thereof. The side plate (412) and the movable plate (413) are both two pieces, and the two side plates (412) are symmetrically fixed to the two sides of the bottom plate (411) through the threaded holes. The opposite surfaces of the two side plates (412) are both provided with a plurality of insertion grooves (414) arranged along the height direction thereof. The side walls of the two movable plates (413) are respectively inserted into the insertion grooves (414) to form the guide groove (41). 3.The rockfall impact structure simulation test system for a shaking table test according to claim 2, characterized in that: The limiting component (4) further includes a servo electric cylinder (42) and a limiting pipe (43). The servo electric cylinder (42) is inclinedly arranged on the rack (1), and the free end of the telescopic rod of the servo electric cylinder (42) is fixedly connected with one end of the limiting pipe (43). The bottom plate (411) and the movable plate (413) are both provided with a through groove (415) for the limiting pipe (43) to pass through. The limiting pipe (43) is used for limiting the sliding of the impact test piece (5).

4. The rockfall impact structure simulation test system for a shaking table test according to claim 3, characterized in that: The limiting component (4) further includes three sets of limiting rods (44), two of which are vertically and symmetrically arranged on the bottom plate (411) and located at the rear end of the impact test piece (5), and the free ends of the limiting rods (44) are connected with horizontally arranged limiting rods (44). The side plate (412) is provided with a through hole (416) for the horizontally arranged limiting rod (44) to pass through.

5. The rockfall impact structure simulation test system for a shaking table test according to claim 3, characterized in that: A plurality of sets of universal steel ball rollers (45) are symmetrically arranged on the rack (1), and the limiting pipe (43) is in sliding connection with the universal steel ball rollers (45).

6. The rockfall impact structure simulation test system for a shaking table test according to claim 1, characterized in that: A high-speed camera (6) is fixedly arranged on the vibration table (2), and the high-speed camera (6) faces the low end outlet of the guide groove (41).

7. The rockfall impact structure simulation test system for a shaking table test according to claim 1, characterized in that: A recovery barrel (7) is fixedly arranged on the vibration table (2), and a buffer is arranged in the recovery barrel (7). The barrel opening of the recovery barrel (7) is located below the low end outlet of the guide groove (41). 8.The rockfall impact structure simulation test system for a shaking table test according to claim 1, wherein: The vibration table (2) is fixedly arranged on the concrete base by bolts. 9.The rockfall impact structure simulation test system for a shaking table test according to claim 1, wherein: The impact test piece (5) is a steel ball, a rockfall or a concrete block.

10. The rockfall impact structure simulation test system for a shaking table test according to claim 1, characterized in that: The test model (3) is a power transmission tower, a bridge pier, a house or a retaining wall.

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