Vibration is what? Types and levels of vibration

Vibration is one of the problems of modern megacities. And every year their intensity is constantly increasing. Why is modern science so actively exploring this problem? Why did vibration measurements become mandatory procedures in many organizations and enterprises? The fact is that vibration is a phenomenon that causes a number of occupational diseases, which gives a reason for doctors to raise questions about measures to eliminate it.

The concept of vibrations

Vibration is a complex oscillatory process that occurs in a wide frequency range. How does it arise? When transferring vibrational energy from a source to a solid body. Usually, vibration means mechanical vibrations, which have a perceptible effect on the human body. This refers to the frequency range from 1.6 to 1000 Hz. The concept of vibration is closely related to sound and noise. They accompany this phenomenon at high rates of oscillatory motion.

What subject in school is studying such a thing as vibration? This BZhD (life safety) is a very important subject. Ensuring labor protection is one of the main problems of Russia raised to the level of national security.

Sources of occurrence

Mechanical vibrations are phenomena that occur in virtually all machines, machines and tools that have unbalanced or unbalanced rotating parts that perform reciprocating and shock motions. The list of such equipment includes stamping and forging hammers, metalworking machines, pneumatic and electric perforators, as well as fans, compressors, pumping units and drives.

If the vibrational motion of a mechanical body occurs at a frequency in the range of up to 20 HZ, then they are perceived only as a vibration. At high frequencies, sound appears. It's vibration with noise. In this case, perception is produced not only by the human vestibular apparatus, but also by its organs of hearing.

Classification of vibration

Vibrational movements can be transmitted in various ways. So, there is a vibration common. This is an oscillatory process, transmitted to the human body through various supporting surfaces. General vibration adversely affects the cardiovascular and nervous systems. In addition, it causes pathology of the digestive tract and organs of motion.

In turn, out of the general vibration are:
- transport, which occurs when driving cars on roads;
- transport and technical, the source of which are the machines and mechanisms involved in the technological process;
- technical, arising during the operation of stationary equipment or transmitted to the areas of service personnel where there are no sources of vibration.

There is also a local vibration. These are vibrational movements transmitted through the hands. If a person experiences such a vibration systematically, then he can develop neuritis with a simultaneous loss of ability to work.

At research of workplaces the harmonious, or sinusoidal vibration is allocated. These are such oscillatory movements, for which the values of their basic index vary according to the sinusoidal law. Such a vibration is encountered in practice especially often.

Vibrational movements are also distinguished by their temporal characteristics. So, there is a constant vibration. Its parameters in its frequency over the observation period change no more than twice.

There is also a fickle vibration. It is characterized by a significant change in the main parameters (more than two times).

When studying a subject, students are given the opportunity to learn more about phenomena such as vibration? This is BDZ. He is taught in high school.

Vibration parameters

To characterize oscillatory movements, the following quantities are used:
- amplitude, showing the greatest deviation from the equilibrium position in meters;
- frequency of oscillations, determined in Hz;
- number of vibrational movements for a second;
- speed of oscillations;
- period of oscillation;
- acceleration of oscillations.

Production Vibration

Questions about reducing the level of vibrational movements that negatively affect the human body are particularly relevant at the stage of developing a technological process that is impossible without the use of machines, machines, etc. But, nevertheless, industrial vibration is a phenomenon that in practice can not be avoided. It arises because of the presence of gaps, as well as surface contacts between individual mechanisms and details. There is a vibration and in the unbalance of the equipment. Often, the vibrational motion increases many times due to resonant phenomena.

Vibration monitoring

To control and further reduce the level of vibration in production, a special vibration measuring and control equipment is used. It allows you to maintain the operability of obsolete equipment and extend the life of new machines and mechanisms.

Everyone knows that the technological process of any industrial enterprise requires the participation of a large number of fans, electrical machines, etc. In order for the equipment not to stand idle, technical services must conduct its timely current or major repairs. This is possible when controlling the level of vibration, which allows us to detect:
- unbalance of the rotor;
Wear of bearings;
- misalignment of gears and other malfunctions and deviations.

The vibration control equipment installed on the equipment produces warning signals with an emergency increase in the amplitude of the oscillation.

The effects of vibration on human health

Vibrational movements primarily cause pathology of the nervous system, as well as tactile, visual and vestibular apparatus. Professional drivers of vehicles and machinists complain about the ailments of the lumbosacral spine. These pathologies are the result of the systematic impact of jogging and low-frequency vibration that occurs at their workplace.

Those on whom the vibrational movements of the equipment are transferred during the technological cycle suffer from pains in the extremities, lower back and in the stomach area, as well as from the lack of appetite. They have insomnia, fatigue and irritability. In general, the picture of the effect of general vibration on a person is expressed in vegetative disorders, accompanied by peripheral limb disorders, decreased sensitivity and vascular tone.

The impact of local vibrational movements leads to spasms of the vessels of the forearms and the hand. In this case, the limbs receive less than the required amount of blood. Together with this, local vibration affects the bone and muscle tissues, as well as the nerve endings that are in them. This leads to a decrease in the sensitivity of the skin, to the deposition of salts in the joints, to deformation and decreased mobility of the fingers. It is worth mentioning that the vibrational movements performed in the low frequency range sharply lower the tone of the capillaries, and at high frequencies there is a spasm of the vessels.

Sometimes a worker has a vibration in his ear. What does this phenomenon represent? The fact is that the frequency of oscillatory movements, transmitted from operating equipment, is very different. However, in a single enterprise there is a rather narrow range of such values. This leads to the appearance of this or that type of vibration, as well as the accompanying noise. So, sounds can have a low, medium and high frequency.

When does the vibration in the ear? What does this state characterize? The fact is that sometimes the equipment creates oscillatory movements that are at the same level as the auditory perception. As a result, there is noise transmitted to the inner ear through the body of the worker and his bones.

In practice, the allowable level of vibration is selected. These are those values that do not have a negative impact on the human body. These parameters depend on many factors (on the time of impact, the purpose of the room, etc.) and are measured by the amplitude of vibration, vibration speed, vibration acceleration and frequency.

The most dangerous levels of vibration

Features of the negative impact of vibrational movements on the human body are determined by the nature of their spread with a combination of mass and elastic elements. A person working standing, this torso, pelvis and lower part of the spine. The upper part of the body and spine are exposed to negative influences on the chair.

The influence of vibration on human health is determined by its frequency spectrum. Those hand mechanisms, whose vibrational motion is lower than 35 Hz, contribute to the appearance of negative changes in the joints and the musculoskeletal system.

The most dangerous vibrations are close to the frequency of oscillation of human organs. This range from 6 to 10 Hz. Oscillations of this frequency also negatively affect psychological health. This frequency could well be the cause of the death of many travelers in the Bermuda Triangle. At values of oscillations from 6 to 10 Hz people have a feeling of fear and danger. Sailors at the same time try to leave their ship as soon as possible. Long exposure to vibration can lead to the death of the crew. This phenomenon is dangerous for the functioning of both individual organs and the whole organism as a whole. It disrupts the central nervous system and metabolism.

A vibration with a large amplitude is very dangerous. It has a negative effect on the bones and joints. With prolonged exposure and high intensity of vibrations, such vibration provokes the development of a vibrational disease. This professional pathology under certain conditions passes into a cerebral form, which is virtually impossible to heal.

Elimination of oscillatory movements

How to avoid vibration in the body? What kind of events should this be to preserve human health? There are two main groups of similar methods. The activities of the first of them are designed to reduce vibration directly in the source of its appearance. Such actions, carried out at the design stage, provide for the use of silent equipment and proper selection of its operation modes. During the construction and further operation of industrial buildings, these activities relate to measures for the use of technically sound equipment.

The second method of reducing vibration is its elimination in the path of propagation. For this, vibration isolation of equipment and air ducts is carried out, vibration isolation platforms are being constructed, workplaces are equipped with special rugs and seats. In addition, it is possible to eliminate vibration in the way of its propagation when performing a whole complex of acoustic and architectural-planning activities. Among them:
- location of vibration sources at maximum distance from protected objects;
- expedient placement of equipment;
- application of the scheme of vibration-proof and rigid attachment of the unit, etc.

Time protection

In order to preserve the health of a person working with hand mechanisms or equipment that transmits vibrational movements to the body, special recreational and labor modes are developed. So, there is a limitation of the time of contact with machines and mechanisms up to 1/3 shift. At the same time, two to three breaks must be arranged for 20-30 minutes. And free from work during the shift is provided for the conduct of industrial gymnastics and a variety of physiotherapy procedures.

Such labor regimes are developed for vibro-dangerous occupations and are a kind of preventive measures aimed at preserving human health.

Numerical name vibration

Contacting different people, each of us behaves quite differently. And all this depends on the attitude to the interlocutor and the current situation. We despise or respect, hate or love, listen to their opinion, or we do not care.

If the person met on the journey is restrained and terse, then this behavior becomes characteristic for us. Merry fellow and joker, on the other hand, make you laugh and will certainly cheer up. How do you know the individuality of a person who is hiding in the depths of his soul? Much will prompt the vibration of the name. What is it? Numerological addition of consonants. Using this method, you can determine the nature of relatives and spouse, friends and anyone, even without knowing the date when he was born. Only knowledge of 9 numerical vibrations corresponding to a name is necessary. With their help, you can pick up the key to the human soul and feel like a real magician. No wonder some say it's a vibration of my heart. After all, with the help of this method, a magic weapon appears in the hands of a person, which will benefit those who know its force of influence and basic meaning.

The letters of each person's name conceal three meanings of his personality. This is a numerical vibration:
- vowels;
- consonants;
- the sum of all letters.

These numerical values in aggregate give a characterization of the most important aspects of the personality.

There is also a sound vibration of a name, because life is a continuous movement. That's why it has its own vibration. And every name has its own vibration. In the course of life, its importance is gradually transferred to the master. Scientists believe that the lower threshold of such vibrations is at the level of 35,000 oscillations per second, and the upper one at the level of 130000 / sec. Those people who have the highest rate are resistant to various kinds of infections. They also have high levels of moral attitudes.