vibration isolation

Vibration Isolation in Data Centers

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Vibrations in Data Centers

Vibrations in Data Centers can be produced by nearby construction works,

heavy traffic, railways or even the own cooling units inside or next the room

and other equipment in the same Data Center introducing vibration noise in the

room.

Additionally, the

Seismic Hazard, Seismic Hazard,

as can seen

in the following

World Seismicity

Map.

Effects of vibration in disk drives

The following data indicate that peak accelerations greater than 0.5 g

(1 g = 10 m/s2) in the servers would be subject to forces that could cause

permanent damage and loss of data readable.

The forces generated by low frequency seismic waves are generally

more destructive than higher frequency vibrations because of their

longer periods generated with larger amplitudes.


According to various manufacturers, Disk Drives Units have a limit even lower

than the servers, see for example the values of HITACHI 9900 Disk Unit

(formerly SUN 9900) indicating its limit in 0.49 m/s2, considering that in normal

operation has a value of 0.10 m/s2.


Latency study in

SUN Disk Drives

Units, the effect

produced after

suffering vibrations

within the rangeaccepted by theaccepted by the

manufacturer, which is

results in loss of

time while discs are

looking for position to

read or write,

some studies report

up lost hours

in 1-10-50 TB copies.

System's natural frequency and vibration isolation solutions

The vibrations cause the system to oscillate at its own vibrational

frequency (each oscillation time or period corresponding to the inverse of

the frequency itself). If the period (or frequency) of the structure matches

that of the building or land where supports, is the phenomenon called

"resonance" in which the effects of vibrations are increasing, increasingly

expanding oscillations are becoming larger due to the accumulation of kinetic energy in the interior of the oscillating mass.kinetic energy in the interior of the oscillating mass.

Designing a proper anti-vibration system is to determine the minimum and

maximum weight of the system to know the mass design elements absorb

these vibrations taking into account the resonance frequency of these same

elements.

Depending on the characteristics of the room can choose protection

systems such as individual springs (1), metallic frames (2) or concrete slabs

(3), either vibration or seismic ones.

1. Individual Springs

One of the proposed solutions are

spring-based systems with or without

sub-frame rated for the Maximum

Weight of the rack, representing this

a problem of effectiveness in racks

with half or less density.


The springs installed have an Own

Frequency of 4.5 Hz to full load.

4 individual springs per rack

1.98 KN=202 kg, total over 800 Kg


The graph shows the effect of a spring protection system installed individually in

each rack. In red the vibrations observed on the ground (in German boden)

produced by near construction works and in blue the signal filtered in the racks,

with a value of 0.10 m/s2.

2. Anti-vibrations Metallic Frame

The Anti Vibrations Metallic Frame is a low frequency isolation resonance with container elements and integrated isolators in their own frame, with

a significant degree of vibration isolation. This type of suspension is best

suited for a case like this where we do not have a real spectrum of vibrations

to be produced, and a frame of this type have the ability to obtain a system

with a low resonance frequency or natural frequency, while the weight is better distributed over the whole system frame, allowing racks have some better distributed over the whole system frame, allowing racks have some

half load without affecting efficacy.


It maintains a low resonance frequency, having a significant variation

in the weight of equipment supported on anti-vibration frame, for

example for a Data Center whose load will be variable over time, with an

estimated total load of the slab 10 Metric Tons (9 T the slab and 1 T IT

equipment), it appears that we are about 4 Hz resonance frequency and this

is so even if we have a significant change in weight.

2. Anti-vibrations Metallic Frame: Technical Features

• Ability to maintain overall stability while obtaining low resonance frequencies,

which provides high performance anti-vibration, thanks to the great stability

obtained by notably reducing the center of gravity of the system.

• Also increases the stability

of the whole system

placing supports more

separated.separated.

• Fast leveling system

integrated in the frame.

• Different thicknesses

of frames.

• Maintaining one

low internal frequency

even with large load

variations.


• Possibility to vary the spacing between the Frame and the floor between 10

mm. and 50 mm.

• Natural frequency (Hz)

• Metallic Frame with

integrated silent blocks.

• Metal container with

high resistance system,high resistance system,

safe and quick access.

• Containers with system

registrable for replacement

the silent blocks.

• Double set silent blocks

for high and low frequencies.


Anti-vibration protection system

by common frame for all 10 racks

of the company, along with its

graphical function efficiency

frequency.

3. Description Floating Slab System

The high-performance floating slab is

a floor isolation system with low resonance frequency and

integrated isolators in container elements inside the concrete slab,

with a high degree of vibration

isolation. This type of suspension is isolation. This type of suspension is

best suited for Data Center

environment in which we do not have

a real spectrum of vibrations that

will occur in an earthquake or possible

nearby construction works, and a slab

of this type have the ability to obtain a

system with a low frequency

resonance or natural frequency.

3. Floating Slabs: Other Applications

Anti-vibration protection systems consist of Floating Slabs have been widely

used by various industries for vibration absorption and attenuation impacts: radio studios, TV studios, recording studios, industrial washing

machines, refrigeration equipment, electrical transformers with oil tank

located between the slab and the transformer, boilers, elevators, gyms,

bowling alleys, dance halls, cold rooms, machine tools, precision balances

dynamic UPS machinery, printing presses, newspaper presses, and so on.dynamic UPS machinery, printing presses, newspaper presses, and so on.

3. Floating Slabs: Main Specifications

• Concrete slab with integrated silent blocks in the slab itself.

• Metal container with high strength system, safe and fast in binding to mesh.

• Containers with recordable system for replacement of silent blocks.

• Double set of silent blocks for high and low frequencies.

• Levelling system integrated with the whole slab.

3. Floating Slabs: Technical Specifications

• Ability to maintain overall stability while obtaining low resonance frequencies,

which provides high performance vibration, thanks to the great stability

obtained by notably reducing the center of gravity of the whole system.

• Natural frequency (Hz)

3. Floating Slabs: Technical Specifications

• The silent blocks can be replaced by others with different charge or

different natural frequency.

• Fast integrated leveling system of the whole slab.

• Different thicknesses of slab

• Standard thicknesses of slab H1 = 128 mm. and H1 = 148 mm. Other

thicknesses can be supplied. Standard separation S = (from 1-5 mm). For

special cases for further expansion.special cases for further expansion.

• Natural frequency is maintained low even with large load variations

• Possibility to vary the gap between the floor and the slab and from 10

mm. to 50 mm.

• Can be built while maintaining a certain slope.

3. Floating Slab

Floating anti- vibration slab was installed to protect from vibrations

occurred in the Data center, communications equipment and other electronic

equipment sensitive to vibration that occurred as a result of the construction

works being carried next the room at the XXX Hospital.

The project was focused on protection of jackhammers. The jackhammers work about 900 beats per minute, in this case as a result of this work, if we work about 900 beats per minute, in this case as a result of this work, if we

conducted vibration taking action, we would find that we would appear on the

chart several peaks, which we would be saying we have in certain

frequencies a vibrations "that marks the peak" high acceleration.

As a result of the 900 beats, the maximum acceleration would have a 15 Hz

and harmonics of these: 30 Hz, 45 Hz, etc.

3. Floating Slab

On the other hand as a result

of impacts and the time rock

breakage we also produced

peaks at acceleration in a

frequency certain, this will

depend on rock type and soil type where vibrations soil type where vibrations

are propagated, in this case

we had some peaks between

30 and 45 Hz.

In addition, we must take into

account the Compaction

Process, which produces

vibrations at frequencies 25 or

35 Hz, in depending on the

manufacturer of the Compaction

Machine.

Example of Earthquake Protection

ITEM 1: Slab anti-vibration, with earthquakes seismic attenuation to medium-

low level.TECHNICAL DATADimensions slab (m) 10x15Slab area (m2) 150EQUIPMENT AND PEOPLE Weight (kg) maximum load 60.000EQUIPMENT AND PEOPLE Weight (kg) minimum load 18.000Slab Weight (Kg) 54.000Slab Weight (Kg) 54.000Total weight suspended (kg) maximum load 114.000Total weight suspended (kg) minimum load 72.000Over-use load (kg) 41.000Maximum Total Load (kg) 155.000Number of silent blocks per slab 155Rigidity Coefficient of the Slab KN / m 76.462Rigidity Coeffiecient of the Slab Kg / mm. 7.646Resonance Factor slab (r.p.m.) at maximum load 245Resonance Factor slab (Hz) at maximum load 4,08Resonance Factor slab (r.p.m.) at minimum load 308Resonance Factor slab (Hz) at minimum load 5,14% Isolation for 25 Hz (+) 99%% Isolation for 50 Hz (+) 99%% Isolation for 100 Hz (+) 99%Slab thickness (mm) 150


- In addition to the basic anti-vibration system slab, will be placed shock

absorbers stainless steel wire with double slip soles, non-slip sole gives

high isolation to the horizontal movements, in the case of slab fell few cm as

these pads will be separated from the slab .

-Bindings of the shock absorbers to the containers to prevent a possible

shift in case of earthquakes of medium intensity.shift in case of earthquakes of medium intensity.

- Placement on the bottom of each shock absorber of spring container,

attached to the spring and with anti-slip sole, but also a steel machined base

is added to distribute loads and provide the joint between the two. This

got protection against medium intensity earthquakes.

We must stress that raised floor should be "screwed" to the slab, not just

glued, to allow both feet and raised floor tiles move horizontally with the

slab and avoid raised floor collapse.


ITEM 2 (OPTIONAL): To achieve a higher degree of protection should perform a

physical union of all racks with steel springs interposed stainless steel wire

and replace leveling legs for machine feet dampers and stainless steel wire

non-slip soles.

In this way is achieved

greater mass of the systemgreater mass of the system

and prevent them from tipping

to large horizontal forces.

Force is equal to mass

by acceleration, by joining

the mass, we decrease the

accelerations and thus the

movement of equipment

in the Data Center, in

addition braking by

non-slip feet.


ITEM 3 (OPTIONAL): anti-shock system to absorb the slab impact energy

horizontally in case of a earthquake in the 2 horizontal axes X and Y.

The greatest degree of protection to include a concrete wall of 200mm and

the height from the slab to the raised floor, on which are placed horizontally

elastic elements both on the side of the slab and in the raised floor tiles that

move give up their energy to these horizontal elastic.move give up their energy to these horizontal elastic.

The wall will be in charge of making the opposing force to the slab and

withstand the shock. The perimeter space of the room will be protected with

rock wool.

ITEM 4 (OPTIONAL): Increase the seismic mass by increasing the slab

thickness of 150 mm to 200 mm, to improve performance and isolation,

further decreasing the level of acceleration.

vibration isolation

Business

system frame

antivibration frame

higher frequency vibrations

low resonance frequency

anti vibrations metallic

effects of vibrations

hz resonance frequency

data centers vibrations