What are the main reasons for the occurrence of random vibration in electronic machines?

Simply put, sine vibration vibration is about identifying the vulnerable points in a product design or package design, and seeing at which specific frequency point the response is greatest. This is known as the *** vibration point. (Resonant Frequency, Natural Frequency). After finding the *** vibration point, a dwell test is performed at the *** vibration point. (10 min.dwell or more), to determine whether the product can withstand the impact of *** vibration. When doing packagedesign, try to avoid the frequency point. Random vibration should be used to determine the psd level according to different transportation methods, Sinusoidal vibration contains only one frequency of vibration at any instant, while random vibration contains various frequencies of vibration within the spectrum at any instant, and the magnitude of the energy of these frequencies is distributed in accordance with a specified spectral pattern.

Sinusoidal vibration is a deterministic vibration whose state at any instant can be calculated and is a definite value. Random vibration is a non-deterministic vibration, preselection is not possible to determine the instantaneous value of the motion at a given moment on the object, obeying only statistical laws.

Because random vibration encompasses all the frequencies in the spectrum, so the *** vibration point on the sample will be excited at the same time and may affect each other, so the test is more severe than the same magnitude of sinusoidal test.

Theoretically, the peak value of random vibration acceleration may be any number of times its total root-mean-square (RMS) value, but this is not possible in practice, and general standards require that the peak value be no less than three times the total RMS value.

The reciprocating motion of an object or mass relative to an equilibrium position is called vibration. Vibration is divided into sinusoidal vibration, random vibration, compound vibration, scanning vibration, fixed frequency vibration. Describe the main parameters of vibration are: amplitude, velocity vibration and points, acceleration. In the field or laboratory on the vibration system of the physical or model of the test. Vibration system is a mass elastic system excited by a vibration source, such as a machine, structure or its components, living organisms, etc.. Vibration test is developed from the aerospace sector, and now has been promoted to power machinery, transportation, construction and other various industrial sectors and environmental protection, labor protection, its application is increasingly widespread. Vibration test includes response measurement, dynamic characteristic parameter determination, load identification and vibration environment test and so on.