The excitation equipment used in the vibration test room is the vibration table>. When choosing a vibration table, you must Select the appropriate type according to the test frequency range. The electro-hydraulic table is suitable for the medium and low frequency range, the electric table is suitable for the medium and high frequency range, and the vibration frequency of the mechanical table is limited. In addition, the size of the thrust, the quality of the waveform, and the convenience of control Sex is also taken into consideration.
The mechanical vibration table is the earliest and cheapest vibration table. Its operating frequency range is narrow, and usually only sinusoidal vibration tests can be carried out, and the upper limit operating frequency is about 100 Hz. It can be used for vibration tests of transport simulation benches and motor-driven vehicles simulating road driving, but the accuracy is not high. It is still used in many laboratories and is an economical and practical vibration table>.
The electro-hydraulic vibration table is a device that generates low to medium frequency vibrations, which can be used from 0 to 250Hz, and even above 1000Hz. It has large thrust, direct bearing capacity and good waveform, and can complete sine, random and mixed mode vibration tests, especially suitable for low-frequency large-displacement vibration tests. Its main technical indicators include: the peak thrust depends on the oil pressure and the area of the cylinder; the root mean square thrust depends on the oil pressure and the area of the cylinder; the maximum speed depends on the flow of the servo valve; the maximum displacement depends on the stroke of the cylinder. The performance of the electro-hydraulic vibration table depends on the quality of the oil source, and its core component is the electro-hydraulic servo valve, whose flow-frequency response characteristics can directly determine the upper limit of the operating frequency of the vibration table>.
Electric shaking table test system> is the most commonly used type of shaking table, its frequency range is wide, it can realize thrust from 10N to 200kN, sine, random and impact tests, and its waveform The best shaker ever. The performance measurement technical indicators of the electric platform include: sinusoidal peak thrust, random root mean square thrust, maximum no-load acceleration, maximum no-load speed, maximum displacement, operating frequency range and maximum uncompensated carrying capacity. The power amplifier also has some technical indicators. The electric vibration table system can be selected according to the test requirements, and the manufacturer provides the table body and power amplifier combination of different series of thrust products.
The vibrating table is used toMechanical, electric and electro-hydraulic equipment for sinusoidal fixed frequency and sine frequency sweep tests, the former two have slightly different operating frequency ranges, thrust and load-bearing capacities. For low-frequency and large-amplitude vibration or road transportation environment simulation, it is recommended to use an electro-hydraulic table; for tests with low frequency and no need for large-scale vibration, a mechanical vibration table can be considered as a condition. Many shaking tables can provide sinusoidal peak thrust and random root mean square thrust, but how to estimate the random root mean square thrust of some domestic or old shaking tables> is also a factor that must be considered when initially carrying out random vibration tests .
Three types of shaking tables can be used in both sinusoidal fixed-frequency and sine-sweeping frequency tests, but according to the required vibration range, function, and thrust, the mechanical type, electro-hydraulic, or electro-hydraulic shaking table, and attention should be paid to the structure and weight of the table top, as well as the estimation of the random RMS thrust given by the shaking table>.