CN203977614U - Tower vibrationproof swing type damper - Google Patents

Abstract

The utility model relates to a kind of tower vibrationproof pendulum damping tank, is made up of connecting rod, ball pivot, fork, mass and spring; Connecting rod one end and tower body welding, the other end adopts and is threaded with ball pivot; Fork is vertical with connecting rod, one end and ball pivot welding, other end welding quality piece; Spring is parallel with connecting rod, one end and mass welding, the other end and tower body welding; Damper is symmetric arrays.The utility model has solved vibration protection when resonance occurs tower, by increasing the damping of tower body, tower body amplitude is decayed rapidly, the amplitude while reducing tower top resonance, thus reduce the destruction that resonance causes tower.

Description

Tower vibrationproof swing type damper

Technical field

The utility model relates to the development and Design of the tower vibrationproof pendulum damping tank under a kind of tower vibrationproof damper, especially wind induced vibration.

Background technology

Tower is one of most important equipment in Chemical Manufacture, once it is very harmful to have an accident as special equipment.Therefore, ensure that tower safe operation is very important.

The draw ratio of tower is larger.Therefore, at run duration, tower body not only bears the load such as gravity and operating pressure, also can be subject to the very large impact of wind load.Be arranged on outdoor tower, under wind load action, will produce the vibration of both direction.Be a vibration for down wind, the direction of vibration of tower is parallel with wind direction; Another kind be beam wind to vibration, direction of vibration is perpendicular to wind direction, claims again beam wind to vibration or induced vibration.Along with the continuous increase of tower height, tower is subject to the impact of wind load also can be increasing.Larger wind load will be induced tower vibration.In the time that the natural frequency of vibration frequency and tower is suitable, can resonate, cause damage of facilities, cause serious consequence.Therefore the vibrationproof technology of tower has very large researching value.

The measure of tower vibrationproof mainly contains three kinds, increases natural vibration period, adopts disturbing flow device and increases damping ratio.Concerning tower, increase and may destroy original process conditions natural vibration period, increase manufacturing cost; Due to the existence of the annex such as platform, ladder, the disturbing flow devices such as longitudinal fin or spiral fins are installed and are not suitable for all towers; By setting up shock absorber, to increase damping ratio be a comparatively simple and practical method, in chimney or high-rise structures, is widely used.

At present, conventional tower vibration isolation method is mainly and sets up the flow-disturbing such as fin and baffle plate member both at home and abroad, still little for the research of the windproof shock absorber that shakes.

Summary of the invention

The problem that the utility model solves be the vibration protection that when resonance occurs tower, by increasing the damping of tower body, tower body amplitude is decayed rapidly, the amplitude while reducing tower top resonance, thereby reduce the destruction that resonance causes tower.

The technical solution of the utility model is as follows:

A kind of tower vibrationproof swing type damper, is made up of connecting rod 5, ball pivot 2, fork 6, mass 7 and spring 3; Connecting rod 5 one end and tower body 1 weld, and the other end adopts and is threaded with ball pivot 2; Fork 6 is vertical with connecting rod 5, and one end and ball pivot 2 weld, other end welding quality piece 7; Spring 3 is parallel with connecting rod 5, and one end and mass 7 weld, and the other end and tower body 1 weld; Damper is symmetric arrays.

Preferably 4 dampers are 90 ° of arrangements, are arranged on tower top outside.

Preferably length of connecting rod equates with tower body radius.

Preferably spring length equates with length of connecting rod.

Preferably the ratio scope of damper mass gross mass and tower body sole mass (not containing damper) is 0.65%～4%.

Preferably oscillating bar length with the ratio scope of tower height 5%～9%.

Preferably damper setting height(from bottom) is greater than 2/3 tower height.

The utility model is a kind of swing type damper.Its operating principle is: the natural frequency of quality of regulation piece, makes it equate with the first natural frequency of tower; In the time of vibration, mass and tower form the phase difference of pi/2, and the effect counter-force of mass is contrary with the tower direction of motion, thereby has increased tower body damping ratio.In JB4710-2005, there is tower top single order amplitude y _t1design formulas is as follows: wherein y _t1for tower top amplitude, C _lfor lift coefficient, D is tower external diameter, for single order critical wind velocity, H is tower height, and ρ is atmospheric density, λ ₁for design factor, ζ is tower body damping ratio, and E is modulus of elasticity, and I is second moment of area.As can be seen from the above equation, tower body dampingratioζ and tower top amplitude y _t1be inversely prroportional relationship.That is to say, tower body damping ratio is larger, tower top amplitude y _t1just less.

Because device of spring stiffness coefficient is less, the piece of need ensuring the quality of products has enough spaces, equates with tower body radius so length of connecting rod is set.For ensureing that spring initial displacement is zero, and guarantee that mass planar moves, spring length is set and equates with length of connecting rod.Quality by quality of regulation piece and two parameters of oscillating bar length can change the damping ratio of damper.Its effectiveness in vibration suppression is simulated by finite element software ANSYS and lab scale experiment has obtained checking.

This device is provided with 4 dampers, because the relative oscillating bar length of mass translatory distance is very little, therefore can be regarded as moving along horizontal plane.Spring in plane and mass, can produce 4 horizontal control forces, and its size is:

F _TMDj＝k _TMDj(x _TMDj-x _j)+C _TMDj(x _TMDj-x _j)

(j＝1，2，3，4)

The kinetic equation of tower body under Damper Control is:

$\left[M\right]\left\{\stackrel{\·\·}{x}\right\}+\left[C\right]\left\{\stackrel{\·}{x}\right\}+\left[K\right]\left\{x\right\}=\left\{f\right\}+\left\{F_{\mathrm{TMD}}\right\}$

In formula: F _tMDjthe horizontal restoring force that the-the j damper provides;

K _tMDjthe stiffness factor of the-the j damper springs;

C _tMDjthe inherent damping of the-the j damper;

X _tMDjthe-the j damper mass is with respect to the displacement on ground;

X _jthe-the j damper place tower sections is with respect to the displacement on ground;

X _tMDjthe-the j damper mass is with respect to the speed on ground;

X _jthe-the j damper place tower sections is with respect to the speed on ground;

The mass matrix of [M]-tower body;

The damping matrix of [C]-tower body;

The stiffness matrix of [K]-tower body;

the vector acceleration of-tower body;

the velocity vector of-tower body;

{ the motion vector of x}-tower body;

{ f}-wind load vector;

{ F _tMD}-damper active force vector;

Utilize ANSYS finite element software to set up tower and damper model, wind load is carried on tower model, the vibration of simulation tower in wind, and calculate and obtain tower top amplitude y according to above-mentioned formula _t1.By tower top amplitude y after comparison tower body installation damper _t1with original tower top amplitude y _t1obtain effectiveness in vibration suppression.Wherein, tower body adopts SOLID185 unit, and fork and connecting rod adopt BEAM188 unit, and spring adopts COMBIN14 unit, and mass adopts MASS21 unit, and coupling fork tri-the direction degree of freedom of X, Y, Z of holding that overlap with connecting rod are simulated ball pivot.Adopt transient dynamic analysis, wind load is carried in to tower surface with the form of surface pressure, tower body is vibrated, software for calculation calculates damper active force vector { F according to above-mentioned formula _tMD, and this active force is passed to tower body by spring, under wind load and the acting in conjunction of damper active force, calculate tower top amplitude y _t1.After having simulated, make the model of tower and damper and test.The power of applying is vibrated tower, obtains tower top amplitude y by piezoelectric acceleration transducer _t1, utilize dynamic test analyzer to collect experimental data.Obtain following result:

The ratio of mass gross mass and tower body sole mass (not containing damper) is designated as to mass ratio μ.Oscillating bar length is designated as Length Ratio with the ratio of tower height.

In engineering reality, the quality of damper can not be excessive, conventionally sets damper quality and mounting structure mass ratio in 4%, and damper quality and mounting structure mass ratio can not be lower than 0.5%, otherwise effectiveness in vibration suppression is not obvious.Preferably set mass ratio μ scope 0.65%～4%.Along with the increase of mass ratio μ, tower body damping ratio increases gradually, and damper vibration damping effect is more and more obvious.Under the condition that is 9% at Length Ratio, when mass ratio μ is 0.65%, tower body damping ratio becomes original 2.9 times, now tower top amplitude y _t1can reduce approximately 60%; When mass ratio μ is 4%, tower body damping ratio becomes original 6.5 times, now tower top amplitude y _t1can reduce approximately 84%.In the time that mass ratio μ is less than 0.65%, effectiveness in vibration suppression is not good; In the time that mass ratio μ is greater than 4%, damper will bring excessive additional load to tower body.

Find with calculating simulation by experiment, oscillating bar length can not be long, otherwise the suffered moment of torsion of damper fork is excessive, and required installing space is excessive.The too short meeting of oscillating bar length makes the forms of motion of damper mass become swing from translation, effectiveness in vibration suppression variation, preferred length than scope 5%～9%.In the situation that mass ratio μ is 2%, when Length Ratio is 5%, tower body damping ratio becomes original 3.3 times, now tower top amplitude y _t1can reduce approximately 70%; When Length Ratio is 9%, tower body damping ratio becomes original 5 times, now tower top amplitude y _t1can reduce approximately 80%.

Damper vibration damping effect improves with the raising of mass ratio μ and oscillating bar length.In the time of practice, can select oscillating bar length according to concrete installing space.If installing space is less, can select Length Ratio is 5% short fork; In the time that installing space is more rich, selectable lengths is than being that 9% long fork is to reach more excellent effectiveness in vibration suppression.Under the condition that is 2% at mass ratio μ, when Length Ratio is 5%, tower top amplitude y _t1can reduce 70%; When Length Ratio is 9%, tower top amplitude y _t1can reduce 80%.If continue to increase the quality of mass under Length Ratio 9% condition, in the time that mass ratio μ is increased to 4%, tower top amplitude y _t1can reduce 84%.

Brief description of the drawings

Fig. 1 swing type damper installation site sketch;

Fig. 2 swing type damper device sketch;

Fig. 3 connecting rod, ball pivot, fork Local map;

Fig. 4 mass, spring Local map;

Wherein: 1-tower body, 2-ball pivot, 3-spring, 4-backing plate, 5-connecting rod, 6-fork, 7-mass.

Detailed description of the invention

With reference to the accompanying drawings the utility model is described in further detail:

Tower vibrationproof swing type damper of the present utility model, is made up of connecting rod 5, ball pivot 2, fork 6, mass 7 and spring 3, and four dampers are one group, is 90 ° of arrangements, is arranged on tower top outside.As shown in Figure 1, 2.Connecting rod 5 one end and tower body 1 weld, and the other end adopts and is threaded with ball pivot 2, as shown in Figure 3.Fork 6 is vertical with connecting rod 5, and one end and ball pivot 2 weld, other end welding quality piece 7.Spring 3 is parallel with connecting rod 5, and one end and mass 7 weld, and the other end and tower body 1 weld, as shown in Figure 4.

Length of connecting rod is set to be equated with tower body radius.According to actual condition preseting length ratio and mass ratio μ, require the Length Ratio scope of setting 5%～9%, mass ratio μ scope is 0.65%～4%.

Mass is steel ball, at known tower body sole mass m, and spheroid number n, after mass ratio μ, crown radius is determined by unique:

$r^3=\frac{3\mathrm{m\μ}}{31400\mathrm{\πn}}$

Mass by spring by force transmission to tower body, for ensure the quality of products piece and tower body displacement present the phase difference of pi/2, need to carry out setting spring stiffness factor k according to tower body first natural frequency f, make mass motion frequency consistent with tower body first natural frequency f.Device of spring stiffness coefficient k is determined by tower body first natural frequency f and ball quality m:

k＝4π ²f ²m

Example 1

By damper shown in Fig. 2, be arranged on tower top.Connecting rod 5 one end and tower body 1 weld, and the other end adopts and is threaded with ball pivot 2; Fork 6 is vertical with connecting rod 5, and fork 6 one end and ball pivot 2 weld, other end welding quality piece 7; Spring 3 is parallel with connecting rod 5, and one end and mass 7 weld, and the other end and tower body 1 weld; Totally four of dampers, are symmetric arrays.Length of connecting rod is set and equates with tower body radius, it is 2% that mass ratio μ is set.Under these conditions, the Length Ratio that fork is set is respectively respectively 5%, 6.6%, 7.3%, 8% and 9%.Be that k makes the vibration frequency of mass consistent with tower body first natural frequency f by the stiffness of spring is set.By experiment showed, tower top amplitude y _t1increase with oscillating bar length reduces, under corresponding Length Ratio condition, and tower top amplitude y _t1can reduce respectively 70%, 76%, 77%, 79% and 80%.According to experimental model size, utilize ANSYS to set up FEM (finite element) model.Tower body is selected SOLID185 unit, and rod member is selected BEAM188 unit, and spring is selected COMBIN14 unit.Device of spring stiffness coefficient k in setup unit material properties makes mass vibration frequency consistent with tower body first natural frequency f, and mass is selected MASS21 unit, and in setup unit material properties, quality m meets selected mass ratio μ.The result of analog computation is consistent with experiment.

Example 2

By damper shown in Fig. 2, be arranged on tower top.Connecting rod 5 one end and tower body 1 weld, and the other end adopts and is threaded with ball pivot 2; Fork 6 is vertical with connecting rod 5, and fork 6 one end and ball pivot 2 weld, other end welding quality piece 7; Spring 3 is parallel with connecting rod 5, and one end and mass 7 weld, and the other end and tower body 1 weld; Totally four of dampers, are symmetric arrays.Length of connecting rod is set and equates with tower body radius, it is 9% that oscillating bar length ratio is set.Under these conditions, mass ratio μ being set is respectively 0.65%, 1.3%, 2%, 3.3% and 4%.Be that k makes the vibration frequency of mass consistent with tower body first natural frequency f by the stiffness of spring is set.By experiment showed, tower top amplitude y _t1increase with mass ratio μ reduces, in corresponding mass than under condition, tower top amplitude y _t1can reduce respectively 66%, 74%, 77%, 82% and 84%.According to experimental model size, utilize ANSYS to set up FEM (finite element) model.Tower body is selected SOLID185 unit, and rod member is selected BEAM188 unit, and spring is selected COMBIN14 unit.Device of spring stiffness coefficient k in setup unit material properties makes mass vibration frequency consistent with tower body first natural frequency f, and mass is selected MASS21 unit, and in setup unit material properties, quality m meets selected mass ratio μ.The result of analog computation is consistent with experiment.

Claims (8)

1. a tower vibrationproof swing type damper, is characterized in that being made up of connecting rod, ball pivot, fork, mass and spring; Connecting rod one end and tower body welding, the other end adopts and is threaded with ball pivot; Fork is vertical with connecting rod, one end and ball pivot welding, other end welding quality piece; Spring is parallel with connecting rod, one end and mass welding, the other end and tower body welding; Damper is symmetric arrays.

2. damper as claimed in claim 1, is characterized in that four damper numbers are 4.

3. damper as claimed in claim 2, is characterized in that four dampers are 90 ° of arrangements, is arranged on tower top outside.

4. damper as claimed in claim 1, is characterized in that length of connecting rod equates with tower body radius.

5. damper as claimed in claim 1, is characterized in that spring length equates with length of connecting rod.

6. damper as claimed in claim 1, it is characterized in that damper mass gross mass with the ratio scope of tower body sole mass 0.65%～4%.

7. damper as claimed in claim 1, it is characterized in that oscillating bar length with the ratio scope of tower height 5%～9%.

8. damper as claimed in claim 1, is characterized in that damper setting height(from bottom) is greater than 2/3 tower height.