Multifunctional mechanical laboratory comprehensive test bench equipment
One. Test bench function introduction ( teaching equipment | teaching instrument )
This test rig provides a multifunctional experimental platform for mechanics experiments. This set integrates six types of devices: straight beam bending, equal strength beam bending, bending and torsion combination, pure torsion, tensile and compressive deformation, dynamic beam and impact rod. , Combined into a comprehensive experimental equipment. The test bench adopts a combined lever to transmit the load and continuously load the screw. Load, displacement sensors and strain signals are amplified by multi-channel test system, analog-to-digital conversion, processed and displayed by computer, operated by soft panel to realize digital test, and have dynamic and static test functions. The test bench is a domestic leader.
Figure (1) Block diagram of the test system
This test stand has the function of combining various experiments on material mechanics and the function of combining various basic experimental skills. Using this test stand, there can be eighteen major experiments, and each experiment can design a variety of experimental schemes. Completed, most experimental projects are designed and comprehensive experiments.
Figure (2) Appearance of the test bench
1. Experimental device ① Straight beam bending experiment device and cloth piece ② Equal strength beam bending experiment device and cloth piece ③ Bending torsion cylinder experiment device and cloth piece ④ Tension and compression experiment device and sample piece cloth ⑤ Dynamic test device and sample Cloth dynamic beam device and test piece cloth ⑥ Impact bar device and test piece cloth impact bar device and test piece cloth picture
Figure (4) Block diagram of the test rig
2. Comparison diagram of device layout and panel interface
Figure (5) Comparison of test piece layout and panel interface Figure 3. Test bench dynamic and static test system The signals of load, displacement and strain in the test bench test system are collected, amplified, and analog-to-digital converted by a multi-channel test system. . This system has 10 strain channels, and each channel can be connected as 1/4 bridge, half bridge and full bridge, which is suitable for various bridge tests. Through system software, soft panel operation, full digital intelligent design. Each channel is automatically switched and the bridge is automatically balanced. Scanning sampling, fixed-point sampling, fixed-load sampling, real-time data, and curve display are available. The test data can be displayed as a data list or as a graph. Each channel can perform dynamic testing, displaying dynamic waveforms and data. With storage and printing functions.
Figure (6) The setup flow of the application software for the dynamic and static comprehensive tester is shown in Figure (7).
Figure (7) Flow chart of data acquisition and processing of the test bench test system
1 . Main technical indicators of the test bench (1) Load range: 0 to 3000N (2) Displacement range: 0.01 to 15mm (optional)
(3) Leverage ratio: 1: 1 1: 6 1:10 (4) Load sensitivity: 1N
(5) Load error: 2% (6) Overload capacity: 150%
(7) Overall dimensions: 800 × 500 × 1200mm (8) Weight: 100 100
2 . Dynamic and static strain test system performance indicators (1) Working voltage: 220V 50Hz AC (2) Number of channels: 12 loads 1 channel displacement 1 channel (3) range: micro strain (4) bridge connection method: full bridge half bridge 1 / 4 bridges (5) automatic bridge circuit balance: the balance time is about 2 seconds, balance adjustment (6) gain range adjustable capacity can be expanded by computer to 100M using bridge resistors
(7) Multi-level selection of sampling frequency: 10K, 1K, 100 (Hz) (8) Sensitivity: 1 microstrain (9) Accuracy: (10) Linearity:
(11) Signal to noise ratio:> 60db (12) Frequency response range: 0 ~ 10KHz
(13) Input impedance:
3 Experimental items that can be set up on this test bench (1) Pure bending normal stress experiment (confirmation)
(2) Experiment of bending normal stress of laminated beams (comprehensive)
(3) Determination of material elastic modulus and Poisson's ratio (design)
(4) Straight beam bending test (confirmation)
(5) Application experiment of measuring bridge (confirmed)
(6) Deflection measurement experiment (design)
(7) Sensitive number calibration experiment of strain gauges (confirmation)
(8) Principal stress experiment for strain flower determination (design)
(9) Single internal force determination experiment (design)
(10) Experiment of combined bending and deformation (design)
(11) Tension and compression deformation experiment (confirmation)
(12) Bending and torsion combined deformation experiment (design)
(13) Experiment of static indefinite ring measurement (design)
(14) Stability test (confirmation)
(15) Dynamic strain test of a beam of equal strength (comprehensive)
(16) Experiment of dynamic load coefficient measurement (comprehensive)
(17) Transient strain experiment (comprehensive)
(18) Steady-state dynamic stress experiment (comprehensive)
6. Test bed configuration and promotion (I) Standard configuration
1 main body stand 2 dynamic and static testing instrument 1
3 one pure curved beam 4 one equal strength beam
5 one twisted cylinder 6 one bias
7 one piece of tension 8 one deflection meter
9 pieces of pressure rod 10 pieces of impact rod (for dynamic use)
11 Load sensors One 12 Instrument supporting software
13 Instruction Manual (II) Optional Configuration
15 one stacked beam 16 one dynamic beam (for dynamic use)
17 ring piece 18 displacement sensor one
19 One piece of square straight beam 20 One magnetic bracket (three) Prepared by the user
1 Computers, tables and chairs 2 Dial indicators
3 Use environment (including power supply, network cable, etc.)
Project 2 Online experimental scheme design software The online experimental scheme design system, in the material mechanics experiment, is equipped with a combination test bench to develop an online experimental scheme design system. The software contains twelve experimental projects and can be combined with more than 50 experimental protocols. Using this software for program design, multiple experimental programs can be designed for the same experimental project. For each scheme, different devices, test pieces, and measuring points should be analyzed and selected; different strain gauges, compensation methods, bridge connections, bridge arm coefficients; different leverage ratios, loading methods; different stress states, calculations formula. After a series of analysis choices, an experimental scheme is formed and printed out. This experimental scheme design system is the first in China.
Project 3 Experimental Teaching Monitoring System of the Test Bench This system is the experimental software supporting the application of the comprehensive test bench for experimental teaching. The computer configured on the test bench is connected to a local area network, and the process and data curve of the test bench operation are transmitted to the monitored server in real time through the local area network. Make the instructor more convenient to grasp the experimental situation of the whole class of students.
Project 4 Virtual Demo Software This software is the experimental software supporting the comprehensive teaching platform for experimental teaching. It is not necessary to carry out the actual experimental operation on the laboratory test bench, but the virtual demonstration of the experiment can be performed on the computer, so that students can fully understand The whole process of the experiment.
Project five comprehensive test bench for rotating members This test bench is equipped with pure torsion members, bending-torsional combined deformation members, simply supported beams and cantilever beam members, dynamic loading of speed regulating motors, transient loading of force hammers, strain gauge force measurement, and application of telemetry The strain gauge is tested and the computer displays the processed data. There are three types of experiments: the remote measurement experiment of the dynamic stress of the rotating member, the bearing dynamic reaction test experiment and the vibration test.
Item 6 Kinematic Analysis Device This device uses a metal plate structure, which evolves a typical mechanism of theoretical mechanics into a plane motion device. Using this device can not only describe the movement trajectory, but also integrate the concepts, principles and mechanisms of theoretical mechanics, creating a new form of theoretical mechanics experiments, with originality and novelty. With this device, three experiments can be set up: composite motion analysis, rigid body basic motion characteristics analysis and mechanical modeling.