Experimental device and method for testing bulk solid damping and energy dissipation effect

Abstract

The invention discloses an experimental device and method for testing the shock absorption and energy dissipation effect of a bulk solid. The experimental device comprises a steel column, a steel plate base, a sliding block, a square bin, a spring and a guide rod. The four steel columns are vertically arranged, the lower ends of the steel columns are connected with the vibration table through the steel plate base, the steel plate base is provided with mounting holes, the two guide rods are arranged between every two adjacent left and right steel columns in parallel, the square bin is made of acrylic plates and located among the four guide rods, the guide rods are in sliding fit with two sliding blocks, and the sliding blocks are connected with one corner of the side face of the square bin. And the rod body of the guide rod is sleeved with a spring between the sliding block and the steel column. According to the invention, real boundary conditions can be simulated, inertia force and contact force can be separated and measured, and the device and the method are used for researching a bulk solid damping energy consumption effect and a friction energy consumption characteristic of a bulk solid-structure coupling interface.

Description

Technical Field

[0001] This invention relates to the field of engineering seismic resistance and granular mechanics experimental technology, specifically to an experimental apparatus and method for testing the vibration damping and energy dissipation effect of granular materials. Background Technology

[0002] Grain silos, feed silos, and other bulk storage structures are vital lifeline engineering projects. Under earthquake action, the bulk materials inside the silos will generate enormous inertial forces, which are transmitted to the silo structure through complex bulk-solid coupling. This is one of the main causes of damage to such structures.

[0003] Currently, research on these problems largely relies on simplified theories or numerical simulations, lacking physical experimental devices capable of directly and precisely measuring the inertial forces and interfacial contact forces of bulk materials, and quantifying their dynamic coupling relationships and energy dissipation mechanisms. Existing shaking table experiments often treat bulk materials as added mass or the silo as rigid, failing to reveal key energy dissipation mechanisms such as interfacial friction, slippage, and particle rearrangement. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the existing defects and provide an experimental device and method for testing the vibration damping and energy dissipation effect of granular materials. This device and method can simulate real boundary conditions, separate and measure inertial forces and contact forces, and are used to study the vibration damping and energy dissipation effect of granular materials and the frictional energy dissipation characteristics of the granular-structure coupling interface. This invention can effectively solve the problems in the background technology.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an experimental device for testing the energy dissipation effect of granular damping, comprising steel columns, a steel plate base, sliders, a square chamber, springs, and guide rods; four steel columns are vertically arranged, the lower ends of the steel columns are connected to a vibration table through the steel plate base, the steel plate base has mounting holes, two guide rods are arranged parallel between two adjacent steel columns, the square chamber is made of acrylic sheet and is located between the four guide rods, the guide rods are slidably fitted with two sliders, the sliders are connected to a corner of the side of the square chamber, and the rod body of the guide rod is fitted with a spring between the slider and the steel column.

[0006] Preferably, the four corners of the front and rear sides of the container are provided with reserved bolt holes, and there are multiple reserved bolt holes arranged in a linear array along the axis of the guide rod. The slider is provided with a through hole, and the slider is connected to the container by fastening bolts.

[0007] Preferably, two adjacent steel columns are connected by horizontally arranged square steel connectors.

[0008] Preferably, the guide rod is a hollow rod with internal threads at both ends, and the connecting bolt passes through the through hole on the steel column and is adapted to the internal thread at the end of the guide rod.

[0009] Preferably, it also includes an acceleration sensor, a laser displacement sensor, and a contact force sensor; the acceleration sensor is installed at the center of the outer wall of the container to measure the absolute acceleration of the container; the laser displacement sensor is located near the spring to measure the deformation of the spring; and the contact force sensor is attached to the inner wall of the container to measure the normal contact pressure between the bulk particles and the container wall.

[0010] An experimental method for testing the energy dissipation effect of granular damping, using the experimental apparatus for testing the energy dissipation effect of granular damping as described in any one of claims 1-5, includes the following steps:

[0011] S1. Fix the experimental apparatus on the vibration table;

[0012] S2. Fill the container with bulk particles to a predetermined height;

[0013] S3. Apply seismic excitation with specific spectral characteristics through a shaking table;

[0014] S4. Synchronously collect data on the acceleration of the container, the deformation of the spring, and the contact force of the container wall;

[0015] S5. Calculate the total inertial force, interface contact force, and frictional dissipation energy of the system based on the collected data, and analyze the vibration reduction and energy dissipation effect of the granular material on the structure and its reduction coefficient on the inertial force.

[0016] Preferably, multiple sets of comparative experiments are conducted by changing at least one of the following parameters: the type or filling height of the granular particles, the spectral characteristics of the seismic waves input to the shaking table, the stiffness of the spring, and the surface roughness of the inner wall of the container.

[0017] Preferably, in step S4, the deformation of the spring is expressed as follows:

[0018] (1);

[0019] in, This represents the absolute horizontal displacement of the container. This represents the horizontal displacement of the vibration table surface.

[0020] Restoring force provided by the spring assembly It is expressed as follows:

[0021] (2);

[0022] in, The total equivalent stiffness of the spring assembly. The deformation of the spring is measured by a displacement sensor.

[0023] Preferably, in step S5, the total inertial force of the system is expressed as follows:

[0024] (3);

[0025] (4);

[0026] in, For the total mass of the system, For the sake of the warehouse's own quality, For the equivalent mass of the granular material, This refers to the absolute acceleration of the container.

[0027] Preferably, in step S5, within one complete vibration cycle... Inside, the work done by the vibration table on the system through interfacial contact forces is the input energy of the system. It is expressed as follows:

[0028] (5);

[0029] in, The vibration table velocity;

[0030] interfacial friction The energy dissipated during relative sliding, i.e., frictional dissipation energy. This can be obtained by calculating the negative work it does in one cycle:

[0031] (6);

[0032] in, and These represent the relative displacement and relative velocity between the particles and the bin wall, respectively.

[0033] Friction energy consumption ratio Represented as:

[0034] (7);

[0035] The reduction factor is expressed as:

[0036] (8).

[0037] Compared with existing technologies, the beneficial effects of this invention are as follows: at the physical experimental level, it achieves dynamic separation and synchronous measurement of "inertial force of granular materials" and "interfacial contact force," providing direct data support for establishing the functional relationship between the two; it can strictly control and independently change key influencing factors such as seismic wave spectrum characteristics, grain loading height, and interface roughness, and systematically study the role of each parameter in coupled dynamic response and energy dissipation mechanism; the experimental results provide a "benchmark" for calibrating and verifying the microscopic contact parameters (such as friction coefficient) of numerical models such as the discrete element method, greatly improving the reliability of numerical simulation; it can be used to evaluate the seismic safety threshold of existing grain silos and provide theoretical basis and design parameters for the design of new vibration-damping silos based on performance and considering the energy dissipation of granular materials. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the present invention;

[0039] Figure 2 This is a schematic diagram of the square warehouse structure of the present invention.

[0040] In the diagram: 1 steel column, 1.1 connecting bolt, 2 steel plate base, 2.1 mounting hole, 3 slider, 4 square chamber, 4.1 reserved bolt hole, 5 spring, 6 guide rod, 7 square steel connector. Detailed Implementation

[0041] 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" indicating the orientation or positional relationship, they are only corresponding to the drawings of this application for the convenience of describing the present invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation.

[0042] Please see Figure 1-2 The present invention provides the following technical solutions:

[0043] Example 1: An experimental device for testing the energy dissipation effect of granular damping includes steel columns 1, steel plate base 2, sliders 3, square chamber 4, springs 5, and guide rods 6; four steel columns 1 are vertically arranged, and the lower end of the steel column 1 is connected to the vibration table through the steel plate base 2. The steel plate base 2 has mounting holes 2.1. Two guide rods 6 are arranged parallel between two adjacent steel columns 1. The square chamber 4 is made of acrylic plate and is located between the four guide rods 6. Two sliders 3 are slidably fitted on the guide rods 6. The sliders 3 are connected to one corner of the side of the square chamber 4. The rod body of the guide rod 6 is fitted with springs 5 ​​between the sliders 3 and the steel columns 1.

[0044] Simulated ground vibration is input through a vibration table, and the container 4 swings horizontally along the guide rod 6. Bulk particles are filled into the container 4, and the whole system forms a single-degree-of-freedom vibration system that takes into account the mass of the bulk particles. The size of the container 4 can be scaled down according to the actual warehouse size as needed for research.

[0045] It also includes an accelerometer, a laser displacement sensor, and a contact force sensor; the accelerometer is installed at the center of the outer wall of the container 4 to measure the absolute acceleration of the container 4; the laser displacement sensor is placed near the spring 5 to measure the deformation of the spring; the contact force sensor is attached to the inner wall of the container 4 to measure the normal contact pressure between the bulk particles and the container wall; relevant parameters are used for subsequent calculations and verification.

[0046] Spring 5 is used to simulate the stiffness of the structure. In the experiment, the stiffness of spring 5 can be adjusted to simulate the stiffness of the structure when it is damaged to different degrees under the action of an earthquake. By replacing springs with different stiffnesses, the vibration effect of particles under different stiffness states can be measured, thereby observing the vibration reduction and energy dissipation phenomenon of particles.

[0047] Specifically, the guide rod 6 is a hollow rod with internal threads at both ends. The connecting bolt 1.1 passes through the through hole on the steel column 1 and is adapted to the internal thread at the end of the guide rod 6. The guide rod 6 is fixed by the connecting bolt 1.1.

[0048] During the experiment, the bulk particles to be studied (such as wheat and corn) were filled into the square silo 4 to a specified height. Then, a seismic wave spectrum was applied to the shaking table to investigate the frictional energy loss between the particles and the silo wall, and between the particles themselves. The reduction coefficient of the bulk inertial force of the frictional energy loss was studied.

[0049] Example 2: Unlike Example 1, the four corners of the front and rear sides of the container 4 are provided with reserved bolt holes 4.1. There are multiple reserved bolt holes 4.1 arranged linearly along the axis of the guide rod 6. The slider 3 is provided with through holes. The slider 3 is connected to the container 4 by fastening bolts. By adjusting the pre-tightening position of the fastening bolts, a certain initial pre-pressure can be applied to the container 4 and the balance position of the system can be adjusted.

[0050] Example 3: Unlike Example 1, two adjacent steel columns 1 are connected by horizontally arranged square steel connectors 7 to form a whole and prevent out-of-plane displacement.

[0051] Example 4: Based on Example 1, an experimental method for testing the energy dissipation effect of granular damping is also provided, including the following steps:

[0052] S1. Fix the experimental apparatus on the vibration table;

[0053] S2. Fill the container 4 with a predetermined height of loose particles;

[0054] S3. Apply seismic excitation with specific spectral characteristics through a shaking table;

[0055] S4. Synchronously collect data on the acceleration of the container 4, the deformation of the spring 5, and the contact force of the container wall;

[0056] S5. Calculate the total inertial force, interface contact force and frictional dissipation energy of the system based on the collected data, and analyze the vibration reduction and energy dissipation effect of the granular material on the structure and its reduction coefficient on the inertial force.

[0057] The data calculated through the above steps can be used to study the friction between grain particles and the friction properties of the particle-structure coupling interface within a standard granary unit. Under different seismic wave spectral characteristics and grain loading height, the functional relationship between the inertial force of grain particles and the contact force of the bulk-solid coupling interface can be analyzed, and the effect of friction energy dissipation on the reduction of the inertial force of bulk grain and the corresponding damping ratio can be studied.

[0058] Furthermore, multiple sets of comparative experiments were conducted by changing at least one of the following parameters: the type or filling height of the granular particles, the spectral characteristics of the seismic waves input to the shaking table, the stiffness of the spring 5, and the surface roughness of the inner wall of the container 4.

[0059] Specifically, in step S4, the amount of spring deformation is expressed as follows:

[0060] (1);

[0061] in, This represents the absolute horizontal displacement of the container. This represents the horizontal displacement of the vibration table surface.

[0062] Restoring force provided by the spring assembly It is expressed as follows:

[0063] (2);

[0064] in, The total equivalent stiffness of the spring assembly. The deformation of the spring is measured by a displacement sensor.

[0065] Specifically, in step S5, the total inertial force of the system is expressed as follows:

[0066] (3);

[0067] (4);

[0068] in, For the total mass of the system, For the sake of the warehouse's own quality, For the equivalent mass of the granular material, The absolute acceleration of the container;

[0069] Specifically, in step S5, within one complete vibration cycle Inside, the work done by the vibration table on the system through interfacial contact forces is the input energy of the system. It is expressed as follows:

[0070] (5);

[0071] in, The vibration table velocity;

[0072] interfacial friction The energy dissipated during relative sliding, i.e., frictional dissipation energy. This can be obtained by calculating the negative work it does in one cycle:

[0073] (6);

[0074] in, and These represent the relative displacement and relative velocity between the particles and the bin wall, respectively.

[0075] Friction energy consumption ratio Represented as:

[0076] (7);

[0077] The reduction factor is expressed as:

[0078] (8).

[0079] The parts of this invention not described in detail are prior art. It will be apparent to those skilled in the art that this invention is not limited to the details of the above exemplary embodiments, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and are intended to encompass all changes that fall within the meaning and scope of equivalents in the content of this invention.

Claims

1. An experimental apparatus for testing the energy dissipation effect of granular damping, characterized in that: It includes steel columns (1), steel plate base (2), sliders (3), square chamber (4), springs (5) and guide rods (6); four steel columns (1) are vertically arranged, and the lower end of the steel column (1) is connected to the vibration table through the steel plate base (2). The steel plate base (2) has mounting holes (2.1). Two guide rods (6) are arranged in parallel between two adjacent steel columns (1). The square chamber (4) is made of acrylic plate and is located between the four guide rods (6). The guide rods (6) are slidably fitted with two sliders (3). The sliders (3) are connected to one corner of the side of the square chamber (4). The rod body of the guide rod (6) is fitted with a spring (5) between the slider (3) and the steel column (1).

2. The experimental apparatus for testing the energy dissipation effect of granular damping according to claim 1, characterized in that: The four corners of the front and rear sides of the container (4) are provided with reserved bolt holes (4.1). There are multiple reserved bolt holes (4.1) arranged linearly along the axis of the guide rod (6). The slider (3) is provided with through holes and is connected to the container (4) by fastening bolts.

3. The experimental apparatus for testing the energy dissipation effect of granular damping according to claim 1, characterized in that: The two adjacent steel columns (1) are connected by a transversely arranged square steel connector (7).

4. The experimental apparatus for testing the energy dissipation effect of granular damping according to claim 1, characterized in that: The guide rod (6) is a hollow rod with internal threads at both ends. The connecting bolt (1.1) passes through the through hole on the steel column (1) and is adapted to the internal thread at the end of the guide rod (6).

5. The experimental apparatus for testing the energy dissipation effect of granular damping according to claim 1, characterized in that: It also includes an acceleration sensor, a laser displacement sensor and a contact force sensor; the acceleration sensor is installed at the center of the outer wall of the container (4) to measure the absolute acceleration of the container (4); the laser displacement sensor is set near the spring (5) to measure the deformation of the spring; the contact force sensor is attached to the inner wall of the container (4) to measure the normal contact pressure between the bulk particles and the container wall.

6. An experimental method for testing the energy dissipation effect of granular damping, employing the experimental apparatus for testing the energy dissipation effect of granular damping as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Fix the experimental apparatus on the vibration table; S2. Fill the container (4) with a predetermined height of loose particles; S3. Apply seismic excitation with specific spectral characteristics through a shaking table; S4. Synchronously collect data on the acceleration of the container (4), the deformation of the spring (5), and the contact force of the container wall; S5. Calculate the total inertial force, interface contact force, and frictional dissipation energy of the system based on the collected data, and analyze the vibration reduction and energy dissipation effect of the granular material on the structure and its reduction coefficient on the inertial force.

7. The experimental method for testing the energy dissipation effect of granular damping according to claim 6, characterized in that: Multiple comparative experiments were conducted by changing at least one of the following parameters: the type or filling height of the granular particles, the spectral characteristics of the seismic waves input to the shaking table, the stiffness of the spring (5), and the surface roughness of the inner wall of the container (4).

8. The experimental method for testing the energy dissipation effect of granular damping according to claim 6, characterized in that: In step S4, the deformation of the spring (5) is expressed as follows: （1）； in, This represents the absolute horizontal displacement of the container. This represents the horizontal displacement of the vibration table surface. Restoring force provided by the spring assembly It is expressed as follows: （2）； in, The total equivalent stiffness of the spring assembly. The deformation of the spring is measured by a displacement sensor.

9. The experimental method for testing the energy dissipation effect of granular damping according to claim 6, characterized in that: In step S5, the total inertial force of the system is expressed as follows: （3）； （4）； in, For the total mass of the system, For the sake of the warehouse's own quality, For the equivalent mass of the granular material, This refers to the absolute acceleration of the container.

10. An experimental method for testing the energy dissipation effect of granular damping according to claim 6, characterized in that: In step S5, within a complete vibration cycle Inside, the work done by the vibration table on the system through interfacial contact forces is the input energy of the system. It is expressed as follows: （5）； in, The vibration table velocity; interfacial friction The energy dissipated during relative sliding, i.e., frictional dissipation energy. This can be obtained by calculating the negative work it does in one cycle: （6）； in, and These represent the relative displacement and relative velocity between the particles and the bin wall, respectively. Friction energy consumption ratio Represented as: （7）； The reduction factor is expressed as: （8）。

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