SU727907A2 - Dynamic vibration suppressor in liquid filled tank - Google Patents

Description

The invention relates to devices damping vibrations of thin-walled structures containing liquid.

Known dynamic vibration damper in a tank filled with a liquid, made in the form of an elastic shell ⁵ , mixed inside the liquid and appropriately tuned to the frequency of the external impact.

The disadvantage of this device yav- ¹⁰ wish to set up what it works on the principle of frequency diversity, and therefore does not lead to a significant damping of oscillations.

By the main author. St. No. 502146, a dynamic vibration damper in a container filled with a liquid is known, comprising an elastic element, the elastic shell of which is made with rigid _m perforated walls, and an elastic element in the form of a corrugated shell made of plastically deformable material and mounted in an elastic shell, and a rigid wall is common to both shells.

However, the placement of the corrugated shell inside a closed perforated shell leads to a decrease in the attached mass of the liquid. Thus, there is a contradiction for the well-known dynamic quencher: in order to maintain a large added mass of fluid, a very large perforation of the casing is necessary, and to increase damping, it is necessary to significantly reduce perforation of the casing.

The aim of the invention is to increase the efficiency of damping capacity fluctuations by increasing the damping of the damper.

This is achieved by the fact that the elastic shell is made in the form of a bellows, the perforated walls of which are the ends of the elastic element.

The drawing shows a dynamic vibration damper, a longitudinal section.

The dynamic absorber contains bellows 1 and 2 with hugging rigid walls 3 and 4 at the ends and elements 5 for connecting the lower rigid wall 4 with the walls of the tank 6 filled with liquid. The rigid walls' 3 and 4 and the walls of the bellows 1 and 2 form an annular sealed cavity 7 filled with gas. The central part 8 and 9 of each of the rigid walls 3 and 4 belonging to the inner cavity 10 is perforated.

The device operates as follows.

Fluctuations arising in the design through the walls of the tank 6 are transmitted fluid. In this case, the effect of the bellows 1 with the liquid leads to a decrease in the pressure pulsation in the liquid, the oscillation amplitudes of the walls of the vessel 6 and the entire structure.

The optimal characteristics of a dynamic damper are determined by the formulas:

W | AL-2d ² No. ² bi ^ -ii / -Vl + rnlNK, where GR is the added mass of the liquid;

AL is the generalized mass of the structure;

LU is the disturbance frequency;

- the partial frequency of the damper;

FROM? - the required decrement of structural vibrations;

- decrement of the damper oscillations.

Calculations performed according to the above formulas show that the use of a quencher with relatively small dimensions, for example, q / T? = 0.1, where H is the radius of the outer bellows;

R is the radius of the cylindrical shell, allows you to increase the damping of vibrations of the shell several times.

The proposed design of a dynamic damper improves the damping capacity fluctuations.

Claims (1)

This invention relates to a device for damping vibrations of thin-walled structures containing liquids. A dynamic oscillation damper is known in a container filled with a liquid, made in the form of an elastic rim, placed inside the liquid and suitably tuned to a frequency of external effect. A disadvantage of the known device is that it operates on the principle of frequency separation, and therefore does not lead to a significant damping of oscillations; According to the main author. St. N 5O2146 is known as a dynamic damper in a container filled with liquid, containing an elastic element, the elastic shell of which is made with rigid and perforated walls, and an elastic element in the form of a corrugated shell made of plastically deformable material and installed in the outer shell, and the rigid wall is is common to both shells. However, placing the corrugated shell inside a closed perforated shell leads to a decrease in the added mass of fluid. Thus, for a known dynamic quenching, there is a contradiction: in order to maintain a large amount of attached mass of fluid, a very large perforation of the shell is necessary, and to increase the damping it is necessary strongly. reduce the perforation of the shell. The purpose of the present invention is to increase the efficiency of the quenching of the Bole bog by increasing the damping of the quencher. This is achieved by the fact that the elastic shell is formed in the form of a bellows, the perforated walls of which represent the ends of the elastic element. The drawing shows a dynamic vibration damper, a longitudinal section. The dynamic absorber contains silo backgrounds 1 and 2 with common rigid walls 3 and 4 along the ends and elements 5 for connecting the lower rigid wall 4 with the walls of the container 6 filled with liquid. The rigid walls 3 and 4 and the bellows walls (U 1 and 2 form an annular hermetic cavity 7 filled with gas. The central part 8 and 9 of each of the rigid walls 3 and 4 belonging to the internal cavity 10 is perforated. The device works as follows. Vibrations arising in the structure through the walls of the container 6 are transferred to the liquid, while the effect of the silo-phone 1. with the liquid leads to the mind of the body of pressure bullets in the fluid, the amplitudes of the oscillations of the walls of the tank 6 and the whole structure. m (, a), - aj | -Vi-vmlN4, (f -TC-l hi I N4, where rn is the attached mass of the liquid;, M is the generalized mass of the structure; UJ is the frequency of occurrence; W is the partial the oscillation frequency 1aci - c, d is the required decrement of the oscillations of the structure, 0 is the damper oscillation decrement. Calculations performed using the above formula 1M show that Hpsrae absorbers with relatively small dimensions, for example q / T 0.1, where q is outer bellows radius; R is the radius of the cylindrical shell, which allows to increase the damping of the shell oscillations several times. The proposed design of a dynamic damper allows an increase in the efficiency of damping capacitance. The invention Dynamic damper oscillations in a tank filled with liquid, by author. EV, X 502146, characterized in that, in order to increase the effectiveness of the capacitance oscillations by increasing the damper damping, the elastic shell is made in the form of a force1: background, the perforated walls of which are the ends of the elastic element.