The Harm Caused by Vibration and Noise

With the rapid development of modern industry, all kinds of production machinery and transport machinery are increasingly developing towards high speed, high efficiency, high precision and automation. However, with the increase of power and speed of instruments and equipment, the intensity of vibration source in engineering practice is increasing, and the harm caused by vibration and noise is becoming more and more prominent. Vibration brings serious harm to operators, precision instruments, machinery and equipment, and building structures. At the same time, the harmfulness and influence of vibration and noise on people's living environment and physical and mental health can not be ignored. Therefore, the hazards caused by vibration and noise have been paid more and more attention by researchers all over the world. Vibration and noise are harmful in most cases. Vibration hazard has been recognized as one of the seven major environmental hazards in the world. The hazards caused by vibration and noise can be roughly divided into the following aspects:

(1) The harm of vibration to human body
When the vibration exceeds a certain intensity, it will be harmful to human health. Long-term exposure to large vibration and noise can cause insomnia, low back pain, fatigue, weakness, headache, dizziness, sleepiness, gastrointestinal discomfort, loss of appetite, attenuation, and prone to errors, leading to technical accidents. In the long run, people will be slow to react and cause physiological diseases.

(2) Harm of vibration to building structures
When the vibration is applied to the building, that is, mechanical energy is applied to the building structure, it will cause the structural deformation of the building. Vibration makes the deformation of the structure increase continuously and the foundation subsides. When the vibration frequency is similar to or consistent with the frequency of the building structure, the damage will be more serious, and the heavier one may cause the collapse of the building. When the geological condition under the equipment foundation is not good, the vibration will cause uneven settlement of the foundation, damage the workshop and make the equipment unable to work normally.

(3) Noise generation and environmental pollution
At present, machinery, equipment and power are getting bigger and bigger, and the types are becoming more and more diverse. When the vibration generated by machinery and equipment is transmitted to the foundation, floor, wall or other structures, it will cause vibration, and in the form of elastic wave, it will be transmitted along the building structure to other rooms, so that the adjacent air will vibrate. In this way, the vibration of an object is propagated in all directions by air in the form of sound waves, resulting in so-called structural noise or solid noise. Although reinforced concrete and metal are good materials to isolate air noise, they have little effect on reducing solid noise. Often a small pump can make the whole building unsettled.

(4) Influencing the accuracy of precision instruments and equipment
Vibration destroys the accuracy, reliability and sensitivity of precision instruments. If the instrument is located around the strong vibration source, the vibration will have different effects on it. Affect the normal operation of the instrument, or affect the calibration of the instrument, reduce the measurement accuracy, if serious, it will also cause various instruments, especially electrical instrumentation work failure.
 
Therefore, how to effectively reduce the hazards of vibration and noise is a major issue facing the industrial development of all countries in the world. Vibration control is the most direct way to reduce the harm of vibration and noise in engineering practice. Therefore, to control the influence of vibration and noise, the research of vibration control technology is indispensable.