Vibrating table-based layered adjustable grain shearing test device and test method
By designing a layered adjustable grain shear test device based on a vibration table, the problem of difficulty in accurately quantifying the dynamic response of different stacked high grains in the granary in the prior art is solved, and the reliability verification of the effective mass coefficient is achieved, which is suitable for experiments on different grain types and wet grains.
Patent Information
- Application Number
- CN202510475252.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-16
- Publication Date
- 2025-06-27
AI Technical Summary
The prior art is difficult to accurately quantify the dynamic response of different accumulated heights of grain in granaries under seismic loads, and the assumption of effective mass coefficients in seismic specifications lacks sufficient experimental basis.
A layered adjustable grain shear test device based on a vibration table is designed, including a lower box, a sliding layer and an upper box. The acceleration and base shear force of grain particles are measured by the acceleration sensor and pressure box of the sliding layer, and the effective mass coefficient is calculated.
The dynamic response of different accumulated heights of grains in the granary under the earthquake load was realized, and the reliability of the effective mass coefficient value was verified, covering the typical working conditions of different grain types and wet grains.
Smart Images
Figure CN120213749A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of grain storage, and in particular to a layered adjustable grain shearing test device and a test method based on a vibration table. Background Art
[0002] As a typical bulk material, grain has a seismic response that is significantly different from that of a rigid body or continuous medium. Under the action of an earthquake, the grain particles inside the grain pile will slide, separate, and redistribute, resulting in the effective mass being much lower than the total mass. The current seismic code GB50011-2010 "Code for Seismic Design of Buildings" usually uses the empirical coefficient method to simplify the effective mass of grain to 80% of the total mass, but this assumption lacks sufficient experimental basis, especially ignoring the following key factors: Stratification effect: There are significant differences in the movement of particles at different depths in the grain pile. The upper layer of grain is prone to sliding, while the lower layer is more constrained by the side walls; Nonlinear response: The effects of seismic wave frequency, amplitude, and the physical state of grain, such as humidity and density, on the effective mass have not yet been quantified; Traditional research methods mainly estimate effective mass indirectly through overall vibration table tests or numerical simulations. Such research methods have many shortcomings, such as: coarse data granularity: only the overall base shear force of the granary can be obtained, and the contribution ratio of each layer of grain cannot be analyzed; over-simplification of the model: in numerical simulations, grain is often assumed to be a continuous medium, and the discreteness of particles is ignored; environmental interference: small changes in grain humidity and stacking density may significantly affect the results, but existing experiments lack dynamic control of these variables; Therefore, developing a grain shear box that can verify the reliability of an effective mass coefficient of 80% under granary seismic loads through layered dynamic response monitoring has become a key issue that needs to be urgently addressed in the study of the seismic mechanism of bulk materials. Summary of the invention
[0003] The technical problem to be solved by the present invention is to overcome the existing defects and provide a layered adjustable grain shear test device and test method based on a vibration table, which can quantify the dynamic response of grains with different stacking heights in a granary under seismic loads, verify the reliability of the effective mass coefficient value, and effectively solve the problems in the background technology.
[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a layered adjustable grain shear test device based on a vibration table, comprising a lower box, a sliding layer and an upper box; The lower box body includes a base, a lower granary and a composite layer 1, the lower part of the lower granary is connected to the base and sealed, the upper opening of the lower granary has a storage bin, two opposite sides of the storage bin protrude from the lower granary and form a sliding friction interface, the sliding friction interface has a composite layer 1, the linear sliding in the storage bin is matched with a sliding layer, and the sliding layer and the composite layer 1 slide in contact; The sliding layer includes a frame. Composite layers II are provided on both opposite sides of the upper opening of the frame, and there is a gap between the two composite layers II; The upper box body is fixed to the upper part of the lower box body, and the lower part of the upper box body is in sliding fit with the composite layer II of the sliding layer; When the sliding layer slides in the accommodation bin, it is always hermetically closed with the upper box body; An acceleration sensor is provided at the center of the sliding layer, and a pressure box is provided at the bottom of the sliding layer.
[0005] Preferably, the base is rigidly connected to the shaking table through high-strength bolts, and the base is provided with bolt holes for the high-strength bolts to pass through.
[0006] Preferably, both the composite layer I and the composite layer II are composite curing layers of grain particles and resin.
[0007] Preferably, sliding rails are provided on both opposite side walls of the accommodation bin, and sliding blocks adapted to the sliding rails are provided on both opposite side walls of the sliding layer.
[0008] Preferably, the upper box body includes two stacked box bodies. The upper and lower box bodies are fixedly connected by bolts. A cover plate is slidably inserted into the upper opening of the upper box body. Straight tenons are provided on both opposite side walls of the lower box body, and clamping grooves adapted to the straight tenons are provided on both opposite side walls of the accommodation bin.
[0009] Preferably, two baffles are symmetrically provided at the upper opening of the frame of the sliding layer, and the composite layer II is provided on the baffles.
[0010] Preferably, the lower box body, the sliding layer, and the upper box body are all made of polymethyl methacrylate with high light transmittance.
[0011] A layered adjustable grain shear test method based on a shaking table includes the following steps: a. Assemble the lower box body, the sliding layer, and the upper box body, and fix the lower box body to the shaking table through high-strength bolts; b. Use a grain pump to fill the lower box body, the sliding layer, and the upper box body with grains according to preset working conditions (grain type, humidity, density), fill the grains to the target height and record; c. The shaking table outputs seismic waves of different frequencies for 10 seconds; d. Measure the base shear force through the pressure box at the bottom of the sliding layer and measure the acceleration of the grain particles under the earthquake action through the accelerometer at the center position of the sliding layer. Each group of working conditions is repeated 3 times, and the data is recorded; e. Effective mass calculation, calculate the effective mass according to Newton's second law: , calculate the effective mass coefficient: *100%, where, is the collected base shear force, is the collected acceleration, is the total mass of the grain-filled sliding layer; f. Sequentially change the stacking height, grain type, humidity, and seismic wave parameters, and repeat the above experimental steps; g. According to the experimental data, plot the variation curves of the effective mass coefficient n with the stacking height and seismic wave frequency, compare the coefficient differences under different grain types and humidities, analyze the influence of friction characteristics, and verify the deviation range of the 80% empirical value.
[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: Real friction interface simulation: The friction coefficient of the grain particle-resin composite layer is adjustable, covering typical working conditions of different grain types such as wheat and corn; Modular scalability: The height of the upper box body is adjustable, supporting multi-scenario simulations from shallow flat warehouses to deep silos; The slide rail-slider allows for quick replacement of friction modules, adapting to comparative experiments of dry and wet grains; Enhanced engineering applicability: The closed sliding structure (displacement self-adaptive seal) ensures no particle leakage under large displacement shear; A mixed curing layer of grain particles and resin is pre-laid on the surface of the sliding layer, and the resin only serves as an adhesive to fix part of the grain particles, leaving exposed contact points between the particles, ensuring that the friction characteristics are dominated by direct contact between the particles rather than the resin interface. Through the above structure, a shear test of grains under vibration conditions is simulated; The purpose of verifying whether the 80% empirical value in the Seismic Design Code for Buildings GB 50011-2010 is accurate is achieved through the test method. Description of the Drawings
[0013] Figure 1 is the structural schematic diagram of the present invention; Figure 2 is the structural schematic diagram of the lower box body of the present invention; Figure 3 is the structural schematic diagram of the sliding layer of the present invention; Figure 4 is the cross-sectional view of the sliding layer of the present invention; Figure 5 is the structural schematic diagram of the upper box body of the present invention; Figure 6 is the cross-sectional view of the present invention.
[0014] In the figures: 1 lower box body, 1.1 base, 1.2 lower grain bin, 1.3 first composite layer, 1.4 receiving bin, 2 sliding layer, 2.1 slider, 2.2 second composite layer, 3 upper box body, 3.1 straight tenon, 3.2 bolt, 3.3 cover plate. Detailed Embodiments
[0015] The present invention can be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "rear", "left", "right", etc. indicating the orientation or positional relationship, it is only corresponding to the drawings of the present application. For the convenience of describing the present invention, it does not indicate or imply that the device or element referred to must have a specific orientation.
[0016] Please refer to Figures 1-6 , the present invention provides a technical solution: a layered adjustable grain shearing test device based on a shaking table, including a lower box body 1, a sliding layer 2 and an upper box body 3; The lower box body 1 includes a base 1.1, a lower grain bin 1.2 and a first composite layer 1.3. The lower part of the lower grain bin 1.2 is connected to and sealed with the base 1.1. The upper part of the lower grain bin 1.2 has an accommodation bin 1.4. Both opposite sides of the accommodation bin 1.4 protrude from the lower grain bin 1.2 and form a sliding friction interface. The sliding friction interface has a first composite layer 1.3. A sliding layer 2 is linearly slidably fitted in the accommodation bin 1.4, and the sliding layer 2 is in sliding contact with the first composite layer 1.3. The sliding layer 2 includes a frame. Both opposite sides of the upper opening of the frame are provided with a second composite layer 2.2, and there is a gap between the two second composite layers 2.2; The upper box body 3 is fixed to the upper part of the lower box body 1, and the lower part of the upper box body 3 is in sliding contact with the second composite layer 2.2 of the sliding layer 2; When the sliding layer 2 slides in the accommodation bin 1.4, it is always hermetically closed with the upper box body 3. The maximum unilateral sliding displacement of the sliding layer 2 is designed to be 25% of the width of the box body, ensuring the closure of the box body and the upper box body 3 under extreme displacements and preventing particle leakage; An acceleration sensor is provided at the center of the sliding layer 2, and a pressure box is provided at the bottom of the sliding layer 2 for measuring test data to facilitate subsequent calculation and analysis; Further, the base 1.1 is rigidly connected to the shaking table through high-strength bolts. The base 1.1 is provided with bolt holes for the high-strength bolts to pass through. The base 1.1 is rigidly connected to the shaking table through 15-mm-diameter high-strength bolts to ensure lossless transmission of power input; Further, both the first composite layer 1.3 and the second composite layer 2.2 are grain particle and resin composite cured layers. By using the grain particle and resin composite cured layer, while simulating the friction on the grain surface, it prevents the scattering of grain particles. The real friction interface simulation can cover the typical working conditions of different grain varieties such as wheat and corn. The resin only serves as an adhesive to fix part of the grain particles, leaving the exposed contact points between the particles, ensuring that the friction characteristics are dominated by the direct contact between the particles rather than the resin interface; Further, sliding rails are provided on two opposite side walls of the accommodation bin 1.4, and sliding blocks 2.1 adapted to the sliding rails are provided on two opposite side walls of the sliding layer 2, eliminating frictional interference in non-force directions. The sliding rail - sliding block allows for quick replacement of the friction module (sliding layer 2), suitable for comparative experiments of dry and wet grains; Further, the upper - layer box body 3 includes two boxes stacked up and down. The two boxes are fixedly connected by bolts 3.2. A cover plate 3.3 is slidably inserted into the upper opening of the upper box. Straight tenons 3.1 are provided on two opposite side walls of the lower box. Groove slots adapted to the straight tenons 3.1 are provided on two opposite side walls of the accommodation bin 1.4. The upper - layer box body 3 is installed on the upper part of the lower - layer box body 1 through plug - in fit. The cover plate 3.3 can be pulled out and opened to facilitate adding grains or weights inside. The bolt connection enables stepped height adjustment and weights can be placed on the top layer, simulating different grain - filling masses while reducing the usage amount of grains; Further, two baffles are symmetrically provided at the upper opening of the frame of the sliding layer 2, and the composite layer two 2.2 is arranged on the baffles to provide support for the composite layer two 2.2; In addition, the lower - layer box body 1, the sliding layer 2, and the upper - layer box body 3 are all made of polymethyl methacrylate with a high light transmittance, and the light transmittance ≥ 92%. Through a non - invasive optical observation window, visual dynamic monitoring of the movement trajectory, displacement field, and local shear slip behavior of grain particles under seismic wave excitation is realized, providing direct experimental evidence for verifying the inertial force distribution and effective mass coefficient of granular materials.
[0017] A layered adjustable grain shear test method based on a shaking table, characterized in that it is applied to a layered adjustable grain shear test device according to any one of claims 1 - 7, and includes the following steps: a. Assemble the lower - layer box body 1, the sliding layer 2, and the upper - layer box body 3, and fix the lower - layer box body 1 on the shaking table through high - strength bolts; b. Use a grain pumping machine to fill the lower - layer box body 1, the sliding layer 2, and the upper - layer box body 3 with grains according to the preset working conditions of grain type, humidity, and density, fill the grains to the target height and record; c. The shaking table outputs seismic waves of different frequencies for 10 seconds; d. Measure the base shear force through the pressure box at the bottom of the sliding layer 2 and measure the acceleration of grain particles under seismic action through the accelerometer at the central position of the sliding layer 2. Each working condition is repeated 3 times and the data is recorded; e. Calculate the effective mass. Calculate the effective mass according to Newton's second law: , calculate the effective mass coefficient: *100%, where is the collected base shear force, is the collected acceleration, is the total mass of the grain filled in the sliding layer 2; f. Sequentially change the stacking height, grain type, humidity, and seismic wave parameters, and repeat the above experimental steps; g. Plot the variation curves of the effective mass coefficient n with the stacking height and seismic wave frequency according to the experimental data, compare the coefficient differences under different grain types and humidities, analyze the influence of friction characteristics, and verify the deviation range of the 80% empirical value; By the above steps, measure the value of the effective mass coefficient under the seismic load of the grain warehouse, quantify the dynamic response of the grain at different stacking heights in the grain warehouse under the seismic load, and verify the reliability of the value of the effective mass coefficient.
[0018] The parts not detailed in the present invention are the prior art. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention; therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, aiming to include all changes falling within the meaning and scope of the equivalent elements in the content of the present invention.
Claims
1. A layered adjustable grain shear test device based on a vibration table, characterized in that: It comprises a lower box body (1), a sliding layer (2) and an upper box body (3); The lower box body (1) comprises a base (1.1), a lower granary (1.2) and a composite layer 1 (1.3); the lower part of the lower granary (1.2) is connected to the base (1.1) and sealed; the upper opening of the lower granary (1.2) has a storage bin (1.4); two opposite sides of the storage bin (1.4) protrude from the lower granary (1.2) and form a sliding friction interface; the sliding friction interface has a composite layer 1 (1.3); the storage bin (1.4) is linearly slidably matched with a sliding layer (2); the sliding layer (2) and the composite layer 1 (1.3) are fitted and slid; The sliding layer (2) comprises a frame, and two opposite sides of the upper opening of the frame are provided with composite layers 2 (2.2), and a gap is provided between the two composite layers 2 (2.2); The upper box body (3) is fixed to the upper part of the lower box body (1), and the lower part of the upper box body (3) slides in contact with the second composite layer (2.2) of the sliding layer (2); When the sliding layer (2) slides in the containing chamber (1.4), it is always sealed and closed with the upper box body (3); An acceleration sensor is provided at the center of the sliding layer (2), and a pressure box is provided at the bottom of the sliding layer (2).
2. The layered adjustable grain shear test device based on a vibration table according to claim 1 is characterized in that: The base (1.1) is rigidly connected to the vibration table via high-strength bolts, and the base (1.1) is provided with bolt holes for the high-strength bolts to pass through.
3. The layered adjustable grain shear test device based on a vibration table according to claim 1 is characterized in that: The composite layer 1 (1.3) and the composite layer 2 (2.2) are both composite solidified layers of grain particles and resin.
4. The layered adjustable grain shear test device based on a vibration table according to claim 1 is characterized in that: Two opposite side walls of the accommodating bin (1.4) are provided with slide rails, and two opposite side walls of the sliding layer (2) are provided with sliding blocks (2.1) adapted to the slide rails.
5. The layered adjustable grain shear test device based on a vibration table according to claim 1, characterized in that: The upper box body (3) comprises two stacked boxes, the upper and lower boxes being fixedly connected by bolts (3.2); a cover plate (3.3) is slidably inserted into the upper opening of the upper box body; two opposite side walls of the lower box body are provided with straight tenons (3.1); and two opposite side walls of the accommodating bin (1.4) are provided with slots that cooperate with the straight tenons (3.1).
6. The layered adjustable grain shear test device based on a vibration table according to claim 1, characterized in that: The upper opening of the frame of the sliding layer (2) is symmetrically provided with two baffles, and the second composite layer (2.2) is arranged on the baffles.
7. The layered adjustable grain shear test device based on a vibration table according to claim 1, characterized in that: The lower box body (1), the sliding layer (2) and the upper box body (3) are all made of polymethyl methacrylate with high light transmittance.
8. A layered adjustable grain shear test method based on a vibration table, characterized in that: A layered adjustable grain shear test device based on a vibration table as described in any one of claims 1 to 7 comprises the following steps: a. Assemble the lower box body (1), the sliding layer (2) and the upper box body (3), and fix the lower box body (1) on the vibration table by high-strength bolts; b. Use a grain pump to fill grain into the lower box (1), the sliding layer (2) and the upper box (3) according to preset working conditions (grain type, humidity, density), fill the grain to the target height and record it; c. The vibration table outputs seismic waves of different frequencies for 10 seconds; d. The base shear force is measured by the pressure box at the bottom of the sliding layer (2) and the acceleration of the grain particles under the earthquake is measured by the accelerometer at the center of the sliding layer (2). Each set of working conditions is repeated 3 times and the data is recorded; e. Effective mass calculation: Calculate the effective mass according to Newton's second law: , calculate the effective mass coefficient: *100%, of which: is the collected base shear force, is the collected acceleration, is the total mass of grain filled in the sliding layer (2); f. Change the stacking height, grain type, humidity, and seismic wave parameters in turn and repeat the above experimental steps; g. Based on the experimental data, draw a curve of the effective mass coefficient n changing with the stacking height and seismic wave frequency, compare the coefficient differences under different grain types and humidity, analyze the influence of friction characteristics and verify the deviation range of 80% empirical value.