What are random vibrations?
Random vibrations are any vibrations that do not follow the formula. It is to some extent present in a wide range of mechanical and electrical systems. Although accidental vibrations cannot be precisely predicted, statistics can generate useful information for the vibrating environment. Cars on the start of the highway and missiles are two situations that can face intense random vibrations. Engineers use statistics to simulate these vibrations in the laboratory.
Some probabilities of random vibration behavior can often be predicted. For example, if a car on the highway accidentally vibrates in a vertical direction, its future positions above the ground cannot be known exactly. However, the probability that the car will be above a certain height can be predicted. This is possible because random behavior is governed by normal distribution or "bell curve". The behavior of such a system can be analyzed using statistical tools.
Statistical analysis can provide information like the average value of many measurements. In the example of the car can beAverage height outside the ground something like 1 foot (30.5 cm). In a sufficiently large measurement sample, statistics can also provide standard deviations. One of the standard deviations is the distance from the mean value, which contains 68.2% of all data points. For a vibration test of the vehicle, 68.2% of the measuring height of up to 1 inches (2.54 cm) from medium height may be.
When a standard test data deviation has been calculated, engineers can use it to design products. The conditions of random vibrations on many different highways are similar, so statistical data are relatively reliable. Engineers use these data to replicate vibration conditions in the laboratory, where it is easier to perform tests on various product design.
Another situation that experiences accidental vibrations is the start of the rocket. Fúhoř The initial increase in vibration when the engine ignites. A few seconds later, the vibrations are primarily from the engine burning. Then,What the rocket exceeds the speed of sound is mainly vibrations from shock waves and aerodynamic effects on the vehicle. Later, some vibrations may result from smaller nozzles that correct the orientation of the rocket.
As with a car, missiles and their useful load must be designed to survive random vibrations. Engineers must know statistical vibration data to reproduce these conditions in the laboratory. It would be impractical to run the test missile every time it is necessary to test the new design of the useful load. Rather, engineers insert sensors on the running missiles, and then use the data later.