CN110595923A - Electromagnetic axial pressure loading device and axial pressure control method thereof - Google Patents
Electromagnetic axial pressure loading device and axial pressure control method thereof Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M7/00—Vibration-testing of structures; Shock-testing of structures
- G01M7/02—Vibration-testing by means of a shake table
- G01M7/022—Vibration control arrangements, e.g. for generating random vibrations
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M7/00—Vibration-testing of structures; Shock-testing of structures
- G01M7/02—Vibration-testing by means of a shake table
- G01M7/06—Multidirectional test stands
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
- G01N3/38—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces generated by electromagnetic means
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract
The invention provides an electromagnetic axial compression loading device and an axial compression control method thereof, wherein the electromagnetic axial compression loading device comprises a control module, a horizontal actuator, a remote control electromagnet, a counterforce wall and a displacement sensor positioned at the remote control electromagnet; the upper part of the counterforce wall is provided with a horizontal counterforce crossbeam; the top end of the test piece is adjacent to the counter-force beam; a first repulsion magnetic pole of the remote control electromagnet is arranged on the lower end face of the counter-force cross beam, and a second repulsion magnetic pole is connected with the top end of the test piece through a spherical hinge; the horizontal actuator is connected with the top of the test piece to apply horizontal displacement load; a pressure sensor is arranged between the top end of the test piece and the spherical hinge; the remote control electromagnet applies axial pressure to the test piece through magnetic pole repulsion, the control module measures the length of an air gap between a first repulsion magnetic pole and a second repulsion magnetic pole through a displacement sensor, and adjusts the magnetic force of the remote control electromagnet according to the change of the length of the air gap so as to keep the axial pressure applied to the test piece unchanged; the invention can improve the vertical axial pressure loading mode in the structure pseudo-static test, so that the test result is more practical.
Description
Technical Field
The invention relates to the technical field of civil engineering structure performance test research, in particular to an electromagnetic axial pressure loading device and an axial pressure control method thereof.
Background
Although with the development of finite element technology, the numerical simulation of the catastrophe process of the structural earthquake can be realized to a certain extent. But the results of experimental studies are still the subject of the present invention. The pseudo-static force vibration table test is one of the most common methods for researching the earthquake response, the failure mode and the failure mechanism of the structure, and is an important means for evaluating the earthquake resistance of the structure.
In the test of the pseudo-static force vibration table, the vertical force and the horizontal force are loaded, but the existing vertical force loading device, namely the axial pressure loading device has the defects that the applied axial pressure is constant, extra limiting force is generated in the test process and the like. The existing axial compression loading device mostly adopts a jack for loading, but when a loading point applies reciprocating displacement loading, additional limiting force such as additional eccentric force and the like is generated, and if a pulley is installed as a counter-force support for loading the jack so as to reduce the limiting force, the test cost is increased, and the friction coefficient of the pulley also needs to be considered.
Disclosure of Invention
The invention provides an electromagnetic axial pressure loading device and an axial pressure control method thereof, which can improve a vertical axial pressure loading mode in a structural pseudo-static test and enable a test result to be more practical.
The invention adopts the following technical scheme.
An electromagnetic axial compression loading device is used for applying axial pressure to a test piece and comprises a control module, a horizontal actuator, a remote control electromagnet (9), a counterforce wall (1) and a displacement sensor (10) positioned at the remote control electromagnet; the upper part of the counterforce wall is provided with a horizontal counterforce crossbeam (3); the top end of the test piece (5) is adjacent to the counter-force beam; the remote control electromagnet comprises a first repulsive magnetic pole and a second repulsive magnetic pole which are arranged in parallel; the first repulsion magnetic pole is arranged on the lower end face of the counter-force beam; the second repulsive magnetic pole is connected with the top end of the test piece through a spherical hinge;
the horizontal actuator is fixed on the reaction wall, and the force output end of the horizontal actuator is connected with the top of the test piece so as to apply horizontal displacement load to the test piece; a pressure sensor (7) for measuring the axial pressure value borne by the test piece is arranged between the top end of the test piece and the spherical hinge;
the remote control electromagnet applies axial pressure to the test piece through the repulsive force between the first repulsive magnetic pole and the second repulsive magnetic pole, the control module measures the length of an air gap between the first repulsive magnetic pole and the second repulsive magnetic pole through the displacement sensor, and the magnetic force of the remote control electromagnet is adjusted according to the change of the length of the air gap, so that the axial pressure applied to the test piece is kept unchanged.
The displacement sensor is positioned at the side edge of the second repulsive magnetic pole.
The test piece (5) is arranged below the counter-force cross beam and is fixed on the bearing platform (4); the pressure sensor is arranged on the cushion block (6).
A method for controlling the axial pressure of an electromagnetic axial pressure loading device comprises the following steps;
s1, selecting an applicable electromagnet model as a remote control electromagnet according to the magnitude of the axial pressure to be exerted, and exerting the axial pressure on the test piece by the remote control electromagnet when the horizontal actuator does not output a displacement load;
step S2, in the remote control electromagnet, the relationship between the current and the magnetic force and the air gap length has the following formula;
Gδis an air gap permeance, mu0Is magnetic permeability, a is the side length of the remote control electromagnet, delta is the air gap length,the magnetic flux is the magnetic flux of the end face of a magnetic pole, I is the current, W is the number of turns of a coil, S is the total area of the surface of the magnetic pole, F is the repulsive force generated by a working remote control electromagnet, and the air gap length delta and the current I are independent variables; and after the horizontal actuator starts displacement loading according to a preset displacement loading curve, measuring the change of the length of the air gap between the first repulsive magnetic pole and the second repulsive magnetic pole through the displacement sensor.
The above method further includes step S3;
in step S3, the following formula is loaded on the displacement of the horizontal actuator;
here let F*Since other parameters are determined, the current magnitude Δ I ═ I which needs to be adjusted can be obtained*-I。
The above method further includes step S4;
in step S4, the control module includes a single chip microcomputer controller, a computer system, and an electromagnet remote controller, and the control module controls the working voltage of the remote control electromagnet to adjust the working current of the remote control electromagnet, so as to adjust the electromagnetic repulsion between the first repulsive magnetic pole and the second repulsive magnetic pole to adjust the axial pressure applied to the test piece;
the adjustment process is based on the following general formula of current, axial pressure and air gap length;
the invention has the beneficial effects that: the invention can realize single-point and multi-point loading and axial pressure follow-up loading; the electromagnet loading surface can be kept constantly parallel to the upper plane, and the effect of vertical downward consistent with the actual gravity is achieved; and under the loading of reciprocating displacement, no additional limiting force such as friction force, additional eccentric force and the like can be generated because the electromagnet is not in mechanical contact. The invention has convenient installation, economy and practicality, and can adjust the axial pressure in the loading process, thereby being more practical.
Drawings
The invention is described in further detail below with reference to the following figures and detailed description:
FIG. 1 is a schematic diagram of the present invention showing no force output at a horizontal actuator.
FIG. 2 is a schematic structural diagram of the test piece deformed by the displacement load output by the horizontal actuator.
FIG. 3 is a schematic diagram of the system of the present invention
In the figure: 1-a counterforce wall; 2-a horizontal actuator; 3-a counter-force beam; 4-a cushion cap; 5-testing the sample; 6-cushion block; 7-a pressure sensor; 8-spherical hinge; 9-remote control electromagnet; 10-a displacement sensor; 101-a first repulsive magnetic pole; 102-second repulsive magnetic pole.
Detailed Description
As shown in fig. 1-3, an electromagnetic axial pressure loading device is used for applying axial pressure to a test piece, and comprises a control module, a horizontal actuator, a remote control electromagnet 9, a counterforce wall 1 and a displacement sensor 10 located at the remote control electromagnet; the upper part of the counterforce wall is provided with a horizontal counterforce crossbeam 3; the top end of the test piece 5 is adjacent to the counter-force beam; the remote control electromagnet comprises a first repulsive magnetic pole 101 and a second repulsive magnetic pole 102 which are arranged in parallel; the first repulsion magnetic pole is arranged on the lower end face of the counter-force beam; the second repulsive magnetic pole is connected with the top end of the test piece through a spherical hinge 8;
the horizontal actuator is fixed on the reaction wall, and the force output end of the horizontal actuator is connected with the top of the test piece so as to apply horizontal displacement load to the test piece; a pressure sensor 7 for measuring the axial pressure value borne by the test piece is arranged between the top end of the test piece and the spherical hinge;
the remote control electromagnet applies axial pressure to the test piece through the repulsive force between the first repulsive magnetic pole and the second repulsive magnetic pole, the control module measures the length of an air gap between the first repulsive magnetic pole and the second repulsive magnetic pole through the displacement sensor, and the magnetic force of the remote control electromagnet is adjusted according to the change of the length of the air gap, so that the axial pressure applied to the test piece is kept unchanged.
The displacement sensor is positioned at the side edge of the second repulsive magnetic pole.
The test piece 5 is arranged below the counter-force beam and is fixed on the bearing platform 4; the pressure sensor is arranged on the cushion block 6.
A method for controlling the axial pressure of an electromagnetic axial pressure loading device comprises the following steps;
s1, selecting an applicable electromagnet model as a remote control electromagnet according to the magnitude of the axial pressure to be exerted, and exerting the axial pressure on the test piece by the remote control electromagnet when the horizontal actuator does not output a displacement load;
step S2, in the remote control electromagnet, the relationship between the current and the magnetic force and the air gap length has the following formula;
Gδis an air gap permeance, mu0Is magnetic permeability, a is the side length of the remote control electromagnet, delta is the air gap length,magnetic flux at end face of magnetic pole, I current, W number of turns of coil, and S surface of magnetic poleThe total area F is the repulsive force generated by the working remote control electromagnet, wherein the air gap length delta and the current I are independent variables; and after the horizontal actuator starts displacement loading according to a preset displacement loading curve, measuring the change of the length of the air gap between the first repulsive magnetic pole and the second repulsive magnetic pole through the displacement sensor.
The above method further includes step S3;
in step S3, the following formula is loaded on the displacement of the horizontal actuator;
here let F*Since other parameters are determined, the current magnitude Δ I ═ I which needs to be adjusted can be obtained*-I。
The above method further includes step S4;
in step S4, the control module includes a single chip microcomputer controller, a computer system, and an electromagnet remote controller, and the control module controls the working voltage of the remote control electromagnet to adjust the working current of the remote control electromagnet, so as to adjust the electromagnetic repulsion between the first repulsive magnetic pole and the second repulsive magnetic pole to adjust the axial pressure applied to the test piece, so as to keep the axial pressure applied to the test piece unchanged;
the adjustment process is based on the following general formula of current, axial pressure and air gap length;
example (b):
after the device is started, the top of a test piece is pressed by the remote control electromagnet, then the horizontal actuator applies horizontal displacement load to the top of the test piece, the test piece is deformed, the top of the test piece generates horizontal displacement, the magnetic repulsion surfaces of the first repulsion magnetic pole and the second repulsion magnetic pole generate relative movement change at the moment, in order to prevent the axial pressure change of the test piece, the control module controls the working voltage of the remote control electromagnet to adjust the working current of the remote control electromagnet, the axial pressure of the test piece is adjusted by adjusting the electromagnetic repulsion between the first repulsion magnetic pole and the second repulsion magnetic pole, and the axial pressure of the test piece is kept unchanged.
Claims (6)
1. The utility model provides an electromagnetism axle pressure loading device for exert axial pressure to the test piece, its characterized in that: the loading device comprises a control module, a horizontal actuator, a remote control electromagnet (9), a counterforce wall (1) and a displacement sensor (10) positioned at the remote control electromagnet; the upper part of the counterforce wall is provided with a horizontal counterforce crossbeam (3); the top end of the test piece (5) is adjacent to the counter-force beam; the remote control electromagnet comprises a first repulsive magnetic pole and a second repulsive magnetic pole which are arranged in parallel; the first repulsion magnetic pole is arranged on the lower end face of the counter-force beam; the second repulsive magnetic pole is connected with the top end of the test piece through a spherical hinge;
the horizontal actuator is fixed on the reaction wall, and the force output end of the horizontal actuator is connected with the top of the test piece so as to apply horizontal displacement load to the test piece; a pressure sensor (7) for measuring the axial pressure value borne by the test piece is arranged between the top end of the test piece and the spherical hinge;
the remote control electromagnet applies axial pressure to the test piece through the repulsive force between the first repulsive magnetic pole and the second repulsive magnetic pole, the control module measures the length of an air gap between the first repulsive magnetic pole and the second repulsive magnetic pole through the displacement sensor, and the magnetic force of the remote control electromagnet is adjusted according to the change of the length of the air gap, so that the axial pressure applied to the test piece is kept unchanged.
2. An electromagnetic axial compression loading device according to claim 1, wherein: the displacement sensor is positioned at the side edge of the second repulsive magnetic pole.
3. An electromagnetic axial compression loading device according to claim 2, wherein: the test piece (5) is arranged below the counter-force cross beam and is fixed on the bearing platform (4); the pressure sensor is arranged on the cushion block (6).
4. A shaft pressure control method of an electromagnetic shaft pressure loading device is characterized by comprising the following steps: an electromagnetic axial compression loading device according to claim 2, wherein the method of controlling the axial pressure applied to the test piece comprises the following steps;
s1, selecting an applicable electromagnet model as a remote control electromagnet according to the magnitude of the axial pressure to be exerted, and exerting the axial pressure on the test piece by the remote control electromagnet when the horizontal actuator does not output a displacement load;
step S2, in the remote control electromagnet, the relationship between the current and the magnetic force and the air gap length has the following formula;
Gδis an air gap permeance, mu0Is magnetic permeability, a is the side length of the remote control electromagnet, delta is the air gap length,the magnetic flux is the magnetic flux of the end face of a magnetic pole, I is the current, W is the number of turns of a coil, S is the total area of the surface of the magnetic pole, F is the repulsive force generated by a working remote control electromagnet, and the air gap length delta and the current I are independent variables; and after the horizontal actuator starts displacement loading according to a preset displacement loading curve, measuring the change of the length of the air gap between the first repulsive magnetic pole and the second repulsive magnetic pole through the displacement sensor.
5. The axle pressure control method of the electromagnetic axle pressure loading device according to claim 4, characterized in that: further comprising step S3;
in step S3, the following formula is loaded on the displacement of the horizontal actuator;
here let F*Since other parameters are determined, the current magnitude Δ I ═ I which needs to be adjusted can be obtained*-I。
6. The axle pressure control method of the electromagnetic axle pressure loading device according to claim 5, characterized in that: further comprising step S4;
in step S4, the control module includes a single chip microcomputer controller, a computer system, and an electromagnet remote controller, and the control module controls the working voltage of the remote control electromagnet to adjust the working current of the remote control electromagnet, so as to adjust the electromagnetic repulsion between the first repulsive magnetic pole and the second repulsive magnetic pole to adjust the axial pressure applied to the test piece, so as to keep the axial pressure applied to the test piece unchanged;
the adjustment process is based on the following general formula of current, axial pressure and air gap length;
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| CN201911016224.0A CN110595923B (en) | 2019-10-24 | 2019-10-24 | Electromagnetic shaft pressure loading device and shaft pressure control method thereof |
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| CN201911016224.0A CN110595923B (en) | 2019-10-24 | 2019-10-24 | Electromagnetic shaft pressure loading device and shaft pressure control method thereof |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114323388A (en) * | 2022-01-19 | 2022-04-12 | 福州大学 | Force-measuring bridge support and force-measuring method |
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| CN114323388B (en) * | 2022-01-19 | 2024-01-23 | 福州大学 | Force measuring bridge support and force measuring method |
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