A student test system and method for dynamic characteristics of cantilever steel beams

Abstract

The present invention belongs to the technical field of student equipment, and discloses a student test system and method for dynamic characteristics of a cantilever steel beam. The bracket is welded into a non-column vertical structure by steel, and a bottom plate is welded at the bottom and placed directly on the ground; a displacement test meter fixture includes a magnet and a folding bracket fixed on the magnet, and the folding bracket is provided with a fixing component for fixing the displacement test meter, and the displacement test meter fixture is directly adsorbed on the bracket by a magnet; the cantilever steel beam is clamped between the bracket and the clamping plate and reinforced and stabilized by high-strength bolts; the strain gauge is tightly attached to the cantilever steel beam by glue, and the vibration pickup is connected to the cantilever steel beam and connected to a dynamic data acquisition system through a wire; the displacement meter is directly fixed on the displacement meter fixture. The present invention connects the dynamic data acquisition system and the vibration pickup to a computer, which makes up for the shortcomings of the current cantilever steel beam experimental device in colleges and universities being simple in design and staying in a static state, and reduces the gap in engineering site experiments.

Description

Technical Field

[0001] The invention belongs to the technical field of student experimental teaching equipment, and in particular relates to a student experimental system and method for dynamic characteristics of a cantilever steel beam. Background Art

[0002] At present, the commonly used existing technologies in the industry are as follows: the cantilever steel beam test is one of the engineering tests. Engineering testing is a very important professional and technical course for majors such as building construction, road and bridge, and underground engineering. It is a very practical course, and engineering experiments are of great significance in helping students master modern engineering technology, improve their ability to analyze and solve problems, and cultivate students' engineering qualities and innovative consciousness. Most college students remain in the theoretical learning stage for most of their knowledge, and their practical ability is relatively lacking. The experimental device for cantilever steel beams in colleges and universities is simply designed and remains in a static state. There is a big gap with the on-site experiments in the project, and it is difficult to achieve the unification of teaching experiments and actual operations on the project site. Some parts of the existing student cantilever steel beam experimental device are directly welded to the workbench, which is inconvenient to move.

[0003] In summary, the problems existing in the prior art are:

[0004] (1) The experimental device for cantilever steel beams in colleges and universities is simple in design and stays in the static state. There is a big gap with the on-site experiments in engineering projects. It is difficult to achieve the unity of teaching experiments and actual operations on the engineering site. As a result, most college students lack practical ability and cannot truly understand the dynamic characteristics of cantilever steel beams. The technical problem is that it is not unified with the actual operations on the engineering site. Therefore, the experiments conducted with the experimental device for cantilever steel beams in colleges and universities cannot be closely linked to reality and have not truly achieved the purpose of teaching experiments.

[0005] (2) Some parts of the existing student cantilever steel beam experimental device are directly welded to the workbench, which is inconvenient to move. The inconvenience in moving the experimental device makes it bulky and can only be placed in a fixed position, taking up space. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a student test system and method for dynamic characteristics of a cantilever steel beam.

[0007] The present invention is implemented in that a cantilever steel beam dynamic characteristics student test system is provided with:

[0008] Bracket;

[0009] The bracket is welded into a non-column vertical structure by steel welding, and a base plate is welded at the bottom, which is placed on the ground; the displacement tester fixing device is provided with a magnet and a folding bracket fixed on the magnet, and the folding bracket is provided with a fixing component for fixing the displacement tester, and the displacement tester fixing device is directly adsorbed on the bracket by a magnet; the cantilever steel beam is clamped between the bracket and the clamping plate and is reinforced and stabilized by high-strength bolts;

[0010] The strain gauge is tightly attached to the cantilever steel beam by glue, the vibration pickup is connected to the cantilever steel beam and connected to the dynamic data acquisition system through a wire; the displacement meter can be directly fixed on the displacement meter fixing device, the resistance displacement meter is connected to the dynamic data acquisition instrument through a wire, and the dynamic data acquisition instrument is connected to the computer through a wire.

[0011] The bracket is welded together by steel and can be placed directly on the ground; the dynamic data acquisition instrument is connected to the computer through a wire, and the collected data can be saved; the displacement meter fixing device plays the role of fixing the displacement meter, and the displacement meter collects the vertical displacement of the cantilever steel beam; through the dynamic data acquisition system and the static resistance strain gauge, the vibration pickup and the computer connection, it makes up for the shortcomings of the current cantilever steel beam experimental device in colleges and universities that is simple in design and remains in the static state, reduces the gap in engineering site experiments, and is easy to achieve the unity of teaching experiments and actual operations on the engineering site, thereby improving the practical ability of most students in colleges and universities.

[0012] Furthermore, the weight loading plate is connected to the middle end and the end of the cantilever steel beam respectively.

[0013] By providing a weight loading plate, the number of weights can be changed to change the magnitude of the external force on the cantilever steel beam, and the arrangement is convenient for generating multiple vibration modes in the test.

[0014] Furthermore, the dynamic data acquisition instrument is in hard contact with the operating table, the operating table is in hard contact with the ground, and the computer is in hard contact with the operating table.

[0015] By providing an operating table, a computer and a dynamic data acquisition instrument can be placed directly on the ground; at the same time, the problem that some parts of the existing student cantilever steel beam experimental device are directly welded to the workbench and are inconvenient to move can be solved.

[0016] Another object of the present invention is to provide a cantilever steel beam data measurement method for implementing the cantilever steel beam dynamic characteristics student test system, the cantilever steel beam data measurement method includes: the information of the dynamic data acquisition system and the computer is automatically completed by the system, the dynamic data system automatically collects dynamic parameters, and the computer records and calculates data by corresponding software.

[0017] Furthermore, the cantilever steel beam data determination method also includes completing the stress and strain test and analysis of the full bridge, half bridge, and 1 / 4 bridge states; the bridge sensor realizes the test and analysis of various physical quantities; the IEPE piezoelectric sensor realizes the test and analysis of vibration acceleration, vibration velocity, and vibration displacement; the piezoelectric sensor realizes the test and analysis of vibration acceleration, vibration velocity, vibration displacement, pressure, and free field;

[0018] Voltage input, in conjunction with thermocouples, eddy current sensors, magnetoelectric speed sensors and various transmitters, can test and analyze a variety of physical quantities; various thermal resistor temperature sensors and thermal resistor adapters can be used to test and analyze temperature.

[0019] In summary, the advantages and positive effects of the present invention are as follows: the present invention realizes multi-channel parallel synchronous high-speed long-term continuous sampling (when multiple channels work in parallel, 256kHz / channel); highly integrated: modularly designed hardware, each module has a 16, 32 or 64-channel chassis form; each computer can control more than multiple channels for synchronous parallel sampling, meeting the measurement requirements of multi-channel, high-precision, high-speed dynamic signals; each channel has an independent voltage amplifier, 24-bit A / D converter, low-pass filter, and anti-mixing filter to eliminate the influence of crosstalk between channels and improve the anti-interference ability of the system; accurate sampling rate: advanced DDS digital frequency synthesis technology produces high-precision and high-stability sampling pulses, ensuring the synchronization, accuracy and stability of multi-channel sampling rates; digital tape drive signal recording function: realize long-term real-time and uninterrupted recording of multi-channel signals; imported Remo connectors: input connectors adopt The imported high-performance Lemo head greatly improves the reliability of small signal input and is also very convenient to operate; signal conditioner: it is equipped with various programmable signal conditioners, channels are automatically identified, and input sensitivity realizes normalized data; speed / counter channel: it can be connected to various pulse / frequency output sensors or counters for the measurement of speed, pulse counting or frequency; signal source output channel: multi-channel outputs are independent of each other and can output a variety of signals, including: sine, sine sweep, random, pseudo-random, burst random, half-sine, square wave, disk output, etc., which can be used with a variety of experimental equipment; it runs on Win2000 / XP / 7 / 8 operating system, with a friendly user interface and simple and flexible operation; the computer communicates with the instrument through the USB3.0 interface, sets parameters (range, sensor sensitivity, sampling rate, etc.), clears, samples, stops, and transmits sampling data in real time.

[0020] Table 1 Comparison between the present invention and the prior art

[0021] BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1The present invention provides a schematic diagram of the structure of a student test system for dynamic characteristics of a cantilever steel beam.

[0023] Figure 2 It is a schematic diagram of the structure of the splint and cantilever steel beam provided in an embodiment of the present invention;

[0024] In the figure: 1. bracket; 2. splint; 3. cantilever steel beam; 4. strain gauge; 5. vibration pickup; 6. resistive displacement meter; 7. displacement meter fixing device; 8. weight loading plate; 9. dynamic data acquisition instrument; 10. computer; 11. operating table. DETAILED DESCRIPTION

[0025] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings.

[0026] In order to solve the above technical problems, the following structural drawings describe the technical solutions of the present invention in detail.

[0027] like Figure 1-Figure 2 As shown, the embodiment of the present invention provides a cantilever steel beam dynamic characteristics student test system including: a bracket 1, a splint 2, a cantilever steel beam 3, a strain gauge 4, a vibration pickup 5, a resistive displacement meter 6, a displacement meter fixing device 7, a weight loading plate 8, a dynamic data acquisition instrument 9, a computer 10, and an operating table 11.

[0028] The bracket 1 is welded by steel into a non-column vertical structure, and a base plate is welded at the bottom, and the base plate is placed on the ground; the displacement tester fixing device is provided with a magnet and a folding bracket fixed on the magnet, and the folding bracket is provided with a fixing component for fixing the displacement tester, and the displacement tester fixing device is directly adsorbed on the bracket 1 through the magnet; the cantilever steel beam 3 is clamped between the bracket 1 and the clamping plate 2 and is reinforced and stabilized by high-strength bolts.

[0029] The strain gauge 4 is tightly attached to the cantilever steel beam by glue, the vibration pickup 5 is connected to the cantilever steel beam 3 and connected to the dynamic data acquisition system through a wire; the resistive displacement meter 6 can be directly fixed on the displacement meter fixing device, the resistive displacement meter 6 is connected to the dynamic data acquisition instrument through a wire, and the dynamic data acquisition instrument 9 is connected to the computer 10 through a wire.

[0030] The weight loading plate 8 is connected to the middle end and the end of the cantilever steel beam respectively.

[0031] The dynamic data acquisition instrument 9 is in hard contact with the operating table 11 , the operating table 11 is in hard contact with the ground, and the computer 10 is in hard contact with the operating table 11 .

[0032] The embodiment of the present invention provides a cantilever steel beam dynamic characteristics student test system and a cantilever steel beam data measurement method, including: the information of the dynamic data acquisition system and the computer is automatically completed by the system, the dynamic data system automatically collects dynamic parameters, and the computer records and calculates data by corresponding software. The software, static resistance strain gauge, and dynamic data acquisition system are all ready-made. This set of equipment allows students to measure the most important parameters in the dynamic characteristics of the structure: natural frequency and damping ratio by simulating the engineering site. The software, static resistance strain gauge, and dynamic data acquisition system are all ready-made, and these parameters can be directly and automatically calculated. These waveforms can be automatically and synchronously recorded by the software.

[0033] The working principle of the present invention is as follows: a quantitative weight loading plate is added to the lower end of the resistance displacement meter 6, the cantilever steel beam 3 vibrates at the same time, the static resistance strain gauge 9 is connected to the strain gauge 4 through a wire to generate data, the vibration pickup 5 is connected to the cantilever steel beam 3 and transmits the data to the dynamic data acquisition instrument 9 through a wire, and transmits it to the computer-related program for storage.

[0034] By placing appropriate weights on the end loading plate first, and then gently flicking it with a finger, the cantilever steel beam is vibrated up and down, and the corresponding first-order vibration mode is generated by the dynamic data acquisition system and computer-related software, and the damping ratio, natural frequency and other related dynamic characteristic parameters can also be obtained; by placing appropriate weights on the middle and end loading plates respectively, and then gently flicking it with a finger, the cantilever steel beam is vibrated up and down, and the corresponding second-order vibration mode is generated by the dynamic data acquisition system and computer-related software, and the damping ratio, natural frequency and other related dynamic characteristic parameters can also be obtained.

[0035] The present invention can complete the test and analysis of stress and strain in full-bridge, half-bridge and 1 / 4-bridge (120Ω three-wire self-compensation) states; cooperate with bridge sensors to realize the test and analysis of various physical quantities; cooperate with IEPE (ICP) piezoelectric sensors to realize the test and analysis of vibration acceleration, vibration velocity, vibration displacement (simulated quadratic integral is optional); cooperate with piezoelectric sensors to realize the test and analysis of vibration acceleration, vibration velocity, vibration displacement (simulated quadratic integral is optional) and pressure, free field; voltage input, cooperate with thermocouples, eddy current sensors, magnetoelectric speed sensors and various transmitters to test and analyze various physical quantities; cooperate with various thermal resistors (such as platinum resistors, copper resistors, etc.) temperature sensors and thermal resistor adapters to test and analyze temperature.

[0036] The present invention realizes multi-channel parallel synchronous high-speed long-term continuous sampling (when multiple channels work in parallel, 256kHz / channel); highly integrated: modular hardware design, each module has a 16, 32 or 64-channel chassis form; each computer can control synchronous parallel sampling of more than multiple channels to meet the measurement requirements of multi-channel, high-precision, high-speed dynamic signals; each channel has an independent voltage amplifier, 24-bit A / D converter, low-pass filter, and anti-aliasing filter to eliminate the influence of crosstalk between channels and improve the anti-interference ability of the system; accurate sampling rate: advanced DDS digital frequency synthesis technology produces high-precision and high-stability sampling pulses, ensuring the synchronization, accuracy and stability of multi-channel sampling rates; digital tape recorder signal recording function: realize long-term real-time and uninterrupted recording of multi-channel signals; imported Lemo connectors: the input connectors use imported high-performance Lemo heads, which greatly improves the reliability of small signal input, The operation is also very convenient; signal conditioner: equipped with various programmable signal conditioners, automatic channel identification, input sensitivity to achieve normalized data; speed / counter channel: can be connected to various pulse / frequency output sensors or counters for speed, pulse counting or frequency measurement; signal source output channel: multi-channel outputs are independent of each other, and can output a variety of signals, including: sine, sine sweep, random, pseudo-random, burst random, half-sine, square wave, disk output, etc., can be used with a variety of experimental equipment; runs on Win2000 / XP / 7 / 8 operating system, user-friendly interface, simple and flexible operation; computer communicates with the instrument through the USB3.0 interface, performs parameter settings (range, sensor sensitivity, sampling rate, etc.), clearing, sampling, stopping and other operations on the collector, and transmits sampling data in real time.

[0037] The software, static resistance strain gauge, and dynamic data acquisition system of the present invention are all readily available. This device allows students to measure the most important parameters in the dynamic characteristics of the structure: natural frequency and damping ratio by simulating the engineering site. The software, static resistance strain gauge, and dynamic data acquisition system are all readily available, and these parameters can be directly and automatically calculated. These waveforms can be automatically and synchronously recorded by the software.

[0038] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the scope of the technical solution of the present invention.

Claims

1. A cantilever steel beam dynamic characteristics student test system, characterized in that: The cantilever steel beam dynamic characteristics student test system includes: Bracket; The bracket is welded into a non-column vertical structure by steel welding, and a base plate is welded at the bottom, which is placed on the ground; the displacement tester fixing device is provided with a magnet and a folding bracket fixed on the magnet, and the folding bracket is provided with a fixing component for fixing the displacement tester, and the displacement tester fixing device is directly adsorbed on the bracket by a magnet; the cantilever steel beam is clamped between the bracket and the clamping plate and is reinforced and stabilized by high-strength bolts; The strain gauge is tightly attached to the cantilever steel beam through glue, the vibration pickup is connected to the cantilever steel beam and connected to the dynamic data acquisition system through a wire; the displacement meter can be directly fixed on the displacement meter fixing device, the resistance displacement meter is connected to the dynamic data acquisition instrument through a wire, and the dynamic data acquisition instrument is connected to the computer through a wire; The weight loading plates are connected to the middle and end of the cantilever steel beam respectively; The dynamic data acquisition instrument is in hard contact with the operating table, the operating table is in hard contact with the ground, and the computer is in hard contact with the operating table.

2. A method for measuring cantilever steel beam data implementing the cantilever steel beam dynamic characteristics student test system of claim 1, characterized in that: The cantilever steel beam data determination method includes: the information of the dynamic data acquisition system and the computer are automatically completed by the system, the dynamic data system automatically collects dynamic parameters, and the computer records and calculates data by corresponding software.

3. The cantilever steel beam data determination method according to claim 2, characterized in that: The cantilever steel beam data determination method also includes completing the stress and strain test and analysis of the full bridge, half bridge, and 1 / 4 bridge states; the bridge sensor realizes the test and analysis of various physical quantities; the IEPE piezoelectric sensor realizes the test and analysis of vibration acceleration, vibration velocity, and vibration displacement; the piezoelectric sensor realizes the test and analysis of vibration acceleration, vibration velocity, vibration displacement, pressure, and free field; Voltage input, in conjunction with thermocouples, eddy current sensors, magnetoelectric speed sensors and various transmitters, to test and analyze a variety of physical quantities; Various thermal resistor temperature sensors and thermal resistor adapters are used together to test and analyze the temperature.

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