CN211147976U - Device for frame modal test - Google Patents

Abstract

The utility model relates to the field of modal testing, in particular to a device for frame modal testing, which comprises a plurality of frame test plates, a plurality of frame test columns and a bottom plate, wherein the plurality of frame test columns are adjustably fixed around the bottom plate; each frame test board is adjustably and fixedly connected with the plurality of frame test columns and is parallel to the bottom plate. The device adopts the convenient connected mode of dismantling to carry out the node consolidation, and simple structure can change experimental operating mode, modal parameter in a flexible way, guarantees that frame construction's natural frequency is in the effective collection interval of sensor.

Description

A device for frame modal testing

technical field

The utility model relates to the field of modal testing, in particular to a device for frame modal testing.

Background technique

Modal analysis is a modern method to study the dynamic characteristics of structures, and it is the application of the system identification method in the field of engineering vibration. In general, modal analysis is a natural vibration characteristic of a structure, and each mode of the structure has its specific modal parameters, including modal frequency, modal damping, and modal shape. For indoor testing, the methods for obtaining these modal parameters are generally divided into two categories: the first is to obtain by finite element calculation, the second is to use sensors and data acquisition equipment to obtain input and output data, and then based on correlation the parameter identification method to obtain. These methods can effectively obtain the modal parameters of the structure, the difference is that the modal parameters obtained based on the experimental data are more reliable than the modal parameters obtained by the finite element calculation, and are closer to the real situation of the structure; but For the means of identifying modal parameters by using the input and output data obtained from modal tests, a corresponding test platform is often needed to realize it.

The devices involved in general frame modal tests often do not have multifunctional features. For example, most of the frame modal test platform nodes are welded or some other connection methods that cannot be quickly disassembled. In addition, in the actual frame modal test, the relevant modal parameters of the structure are often changed according to the test requirements. If the natural frequency of the test device is not within the effective acquisition range of the sensor, the modal test results will be inconsistent. Large deviations may require rebuilding the experimental platform.

That is to say, the traditional frame modal test device usually adopts welding to simulate the clamping constraints, and the experimenter cannot easily and effectively change the experimental conditions of the modal test according to the experimental requirements. On the other hand, since most frame modal tests use steel (aluminum) tubes and steel (aluminum) plates to simulate the column elements of the frame structure, these materials tend to have greater stiffness, and the structural foundation obtained during modal tests The frequency is often high, and general sensors cannot effectively collect them, resulting in the collected structural vibration signals that cannot truly represent the vibration behavior of the structure.

SUMMARY OF THE INVENTION

In order to solve the problems existing in the prior art, the utility model provides a device for frame modal test, which adopts a connection mode that is convenient for disassembly to consolidate the nodes, has a simple structure, and can flexibly change the test conditions and modal parameters. Ensure that the natural frequency of the frame structure is within the effective acquisition range of the sensor.

The utility model adopts the following technical scheme to realize: the device used for frame modal test includes several frame test plates, several frame test columns and bottom plate, and several frame test columns are adjustable and fixed around the bottom plate; The test boards are fixedly connected with a number of frame test columns in an adjustable manner, and are parallel to the bottom plate.

In a preferred technical solution, each frame test plate and each frame test column are connected by right-angle steel sheets, and each frame test column and the bottom plate are connected by right-angle steel sheets.

In a preferred technical solution, the right-angle steel sheet includes a steel sheet body and side wings extending from the steel sheet body, the side wings are perpendicular to the steel sheet body, and both the steel sheet body and the side wings are provided with screw holes.

In a preferred technical solution, a gasket is also provided at the connection between each frame test plate and each frame test column, and the gasket and the right-angle steel sheet are respectively located on the top and bottom end surfaces of the frame test plate.

In a preferred technical solution, a gasket is also provided at the connection between the bottom plate and each frame test column, and the gasket and the right-angle steel sheet are respectively located on the top end surface and the bottom end surface of the bottom plate.

It can be known from the above technical solutions that the main component of the frame modal test platform designed by the present invention is a frame test device. Simple structure, easy disassembly and installation, good shape applicability, modal test conditions can be changed flexibly. Compared with the prior art, the utility model has the following advantages and beneficial effects:

1. The device for frame modal test designed by the utility model has simple principle and convenient manufacture. It adopts bolts, tenon and mortise joints, buckles, etc. to facilitate the disassembly and assembly of joints for joint consolidation. The situation can be changed flexibly.

2. According to the experimental needs, the quality and stiffness of the frame test plate can be changed by changing the material type, density and section size (length, width, thickness) and other parameters of the frame test plate to change the modal frequency of the structure; By changing the material type, density and section size (length, width, thickness) and other parameters of the frame test column, the quality and stiffness of the frame test column can be changed to change the modal frequency of the structure; it is also possible to change the distance between the frame test columns. Spacing, to change the stiffness of the frame test platform, to change the modal frequency of the structure, on the one hand to achieve the purpose of changing the frame modal test conditions, on the other hand, it can also make it have a suitable natural frequency for the modal test, Then it is ensured that the natural frequency of the frame structure is within the effective acquisition range of the sensor.

3. According to the experimental needs, the modal parameters of the structure can be changed by changing the restraint method of the frame structure, the quality of the structure can be greatly changed by adding or removing additional mass blocks on the frame test plate, and the restraint method of the nut can be changed according to the experimental needs. To change the boundary conditions of the frame platform, so as to flexibly change the test conditions and modal parameters.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the device of the present utility model;

Fig. 2 is the joint consolidation schematic diagram of the frame test plate and the test column of the present utility model;

3 is a schematic diagram of a right-angle steel plate of the present invention;

Fig. 4 is the schematic diagram of the utility model adjusting the test column spacing;

FIG. 5 is a schematic diagram of adding a mass block according to the present invention.

Detailed ways

The present utility model will be further described below with reference to the embodiments and the accompanying drawings, but the embodiments of the present utility model are not limited thereto.

Example

As shown in FIG. 1, in this embodiment, the device for frame modal test includes several frame test plates 2, several frame test columns 1 and bottom plate 3, and several frame test columns are adjustably fixed around the bottom plate; Each frame test board is adjustable and fixedly connected with several frame test columns and is parallel to the bottom plate; that is, the fixed positions of several frame test columns around the bottom plate and each frame test board can be adjusted. In this embodiment, the bottom plate is made of a steel plate with a relatively high mass density, so as to ensure that the base and the upper structure will not be translated in the horizontal plane together with the upper structure during the test.

The connection between the frame test plate and the frame test column is shown in Figure 2. This embodiment is described by one of the frame test columns, and the other frame test columns are the same. Each frame test plate and each frame test column are connected by two right-angle steel sheets 4 , and each frame test column and the bottom plate are connected by two right-angle steel sheets 4 . Each right-angle steel sheet includes a steel sheet body 41 and side wings 42 extending from the steel sheet body, the side wings are perpendicular to the steel sheet body, and the steel sheet body and the side wings are provided with screw holes; each right-angle steel sheet is provided with Three screw holes, as shown in Figure 3, are used to fix the right-angle steel sheet to the frame test plate and the frame test column through screws and nuts. In addition, a spacer 5 is also provided at the connection between each frame test plate and each frame test column, and the spacer and the two right-angle steel sheets are respectively located on the top end surface and the bottom end surface of the frame test plate. Similarly, a gasket 5 is also provided at the connection between the bottom plate and each frame test column, and the gasket and the two right-angle steel sheets are respectively located on the top and bottom end surfaces of the bottom plate.

In this embodiment, several frame test columns are fixed on the four corners of the bottom plate, and several frame test columns are connected to the four corners of each frame test plate. The four corners of each frame test plate are provided with four screw holes, so that the steel body of the right-angle steel sheet can be connected with the frame test column through the corresponding screws and nuts. The bottom plate and the four corners of each frame test plate are provided with corresponding gaskets, and the frame test plates are connected by corresponding screws and nuts, so as to ensure the restraint quality of each layer of the frame test plate and the frame test column joints. Each frame test column is provided with screw holes for fixing the flanks of right-angle steel sheets.

The device of the utility model can change the material types of the frame test plate and the frame test column according to the needs of the experiment, and change the mass density, section size (length, width, thickness), etc., to meet the needs of the experiment, so that the natural frequency of the frame is in the sensor. within the measurement range. At the same time, other screw holes are drilled in other parts of the test plate, so that the distance between the test plate and the test column can be changed according to the needs of the experiment, so as to realize the adjustable and fixed connection of several frame test columns and the bottom plate and the frame test plate. Change its stiffness to achieve the purpose of the experiment, as shown in Figure 4. In addition, according to the needs of the experiment, a mass block 6 can be added to the frame test plate, and the effect of the experiment can be achieved by changing the mass of the frame, as shown in FIG. 5 .

The device of the utility model changes the natural frequency of the frame structure, and the principle involved is shown in the following formula:

where ω is the natural frequency of the frame structure, and k and m represent the stiffness and mass of the frame test platform unit, respectively.

The device of the utility model is not only limited to the field of modal testing, but can be used for corresponding vibration control, structural damage identification and other fields; it is not only limited to the frame test of modal testing, but can also be applied to beam rods of modal testing. For the test, just remove the corresponding test board in the frame structure. In addition, the shapes of related gaskets and connecting parts involved in the device of the present invention can be varied.

The above-mentioned embodiments are preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited by the above-mentioned embodiments, and any other changes, modifications, and substitutions made without departing from the spirit and principle of the present utility model , combination and simplification, all should be equivalent replacement methods, which are all included in the protection scope of the present invention.

Claims (8)

1. a device for frame modal test, is characterized in that, comprises some frame test plates, some frame test columns and base plate, and some frame test columns are adjustable and fixed around the base plate; each frame test plate All of them are adjustable and fixedly connected with several frame test columns, and are parallel to the bottom plate. 2. The device for frame modal test according to claim 1, wherein each frame test plate and each frame test column are connected by right-angle steel sheets, and each frame test column is connected to The bottom plates are connected by right-angle steel sheets. 3. The device for frame modal test according to claim 2, wherein the right-angle steel sheet comprises a steel sheet body and side wings extending from the steel sheet body, the side wings are perpendicular to the steel sheet body, and the steel sheet There are screw holes on the sheet body and the side wings. 4. The device for frame modal test according to claim 2, characterized in that, a gasket is also provided at the connection between each frame test plate and each frame test column, and the gasket and the right angle The steel sheets are located on the top and bottom faces of the frame test plate, respectively. 5. The device for frame modal test according to claim 2, wherein a gasket is also provided at the connection between the bottom plate and each frame test column, and the gasket and the right-angle steel sheet are respectively located at The top and bottom surfaces of the base plate. 6. The device for frame modal test according to claim 2, wherein each frame test plate and each frame test column are connected by two right-angle steel sheets, and each frame test The column and the base plate are connected by two right-angle steel sheets. 7. The device for frame modal test according to claim 1, wherein several frame test columns are fixed at the four corners of the bottom plate, and several frame test columns are connected to the four corners of each frame test plate connect. 8 . The apparatus for frame modal testing according to claim 1 , wherein a mass is added to the frame test plate. 9 .

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