Mechanical vibration table
Mechanical vibration table can be divided into two types: unbalanced weight type and cam type. The unbalanced weight type uses the centrifugal force generated when the unbalanced weight rotates to excite the table top of the vibration table, and the excitation force is proportional to the square of the unbalanced moment and the rotational speed. This kind of vibration table can generate sinusoidal vibration, with simple structure and low cost, but it can only work in the frequency range of about 5Hz~100Hz, the maximum displacement is 6mm peak-to-coarse value, and the maximum acceleration is about 10g. The displacement of the moving part of the shaking table depends on the eccentricity of the cam and the arm length of the crankshaft, and the exciting force varies with the mass of the moving part. In the low frequency domain, when the exciting force is large, this kind of shaking table can achieve a large displacement, such as 100mm. However, the working frequency of this vibration table is limited to low frequencies, and the upper limit frequency is about 20Hz. The maximum acceleration is about 3g, and the acceleration waveform is very distorted. Due to the limitation of its performance, the amount of mechanical vibration table will be smaller and smaller in the future.
The maximum value of rms acceleration obtained by random vibration analysis generally cannot exceed several g?