vibration
VIBRATION
phenomena that
can be felt
(Feeling)
VIBRATION
VIBRATION is the back and forth movement of a mass through a state of balance towards a reference point
MECHANICAL VIBRATION is a vibration caused by human activity means / equipment
SHOCK VIBRATION is a vibration that occurs suddenly and momentarily.
SUMBER GETARAN
MECHANICAL EQUIPMENT
STRUCTURE-BORNE SOUND The vibrations are transmitted through solid building elements such as columns, beams and floor plates
AIR-BORNE SOUND
Radiation of vibration / noise sources through building elements to the air.
RESILENT MATERIAL
NATURAL FREQUENCY
RESONANT FREQUENCY
the lowest frequency of vibration that occurs when a mass is supported by a resilent material which is reflected from the initial position and then released
resonance is a phenomenon that occurs when a vibrating system provokes another system to vibrate with a greater amplitude at a certain frequency.
TRANSMISSIBILITY
VIBRATION: Principles and Magnitude
TRANSMIBILITY
Comparison of the vibration strength of the tool transmitted into the structure.
FREQUENCY OF MOVEMENT (DRIVING FREQUENCY)
The frequency of movement of the tool which is characteristic of the tool is as stated in the specifications of the manufacturer.
Magnitude f in Hz
The lower the transmittance the better.
NATURAL FREQUENCY
the lowest frequency of vibration that occurs when the mass supported by the bonding material deflects from its free position.
The amount of fn is in Hz.
THE MORE COMPARISON OF FREQUENCY BETWEEN FREQUENCY OF TOOL MOVEMENT AND NATURAL FREQUENCY (F / FN) WILL BE BETTER.
IMPACT OF VIBRATION
• ACOUSTIC VIBRATION MAY DISTRIBUTE HEARING
• MECHANICAL VIBRATION (1-20 Hz) DOES NOT IMPROVE HEARING.
IMPACT OF MECHANICAL VIBRATION
• the impact of mechanical vibrations on occupational health is related to exposure time and intensity
• vibrations that radiate through the upper limbs are local
• vibrations that spread to the lower limbs (muscles and hip bones will be felt by the whole body
• further effects: nausea, vomiting, headaches, heart palpitations, want to urinate, and defecate
STANDARD VIBRATION LEVEL FOR COMFORT AND HEALTH
KEPMENLH NO. KEP-49/MENLH/11/1996, LAMPIRAN I
FREQUENSI (Hz)
VIBRATION LEVEL(10-6 m) DO NOT
DISTURB DISTURB UNCOMFORTA
BLE PAINFUL
4 < 100 100-500 > 500-1000 > 1000
5 < 80 80-350 >350-1000 > 1000
63 < 70 70-275 > 275-1000 > 1000
8 < 50 50-160 > 160-500 > 500
10 < 37 37-120 > 120-300 > 300
12,5 <32 32-90 > 90-220 > 220
16 < 25 25-60 > 60-120 > 120
20 < 20 20-40 > 40-85 > 85
25 < 17 17-30 > 30-50 > 50
31,5 < 12 12-20 > 20-30 > 30
40 < 9 9-15 > 15-20 > 20
50 < 8 8-12 >12-15 > 15
63 < 6 6-9 > 9-12 > 12
STANDARD MECHANICAL VIBRATION LEVEL BASED ON DAMAGE LEVEL KEPMENLH NO. KEP-49/MENLH/11/1996,
PARAM ETER
FREQ (Hz)
VIBRATION LEVEL(10-6 m)
CATEGORY A CATEGORY B CATEGORY C CATEGORY D
KEC (mm/s)
4 < 2 2 – 7 > 27-140 > 140
5 < 7,5 < 7,5-2,5 > 25 – 130 > 130
FREQ (Hz)
6,3 < 7 < 7 – 21 > 21 – 110 > 110
8 < 6 < 6 –19 > 19 – 100 > 100
10 < 5,2 < 5,2 – 16 > 16 – 90 > 90
12,5 < 4,8 < 4,8 – 15 > 15 – 80 > 80
16 < 4 < 4 – 14 > 14 – 70 > 70
20 < 3,8 < 3,8 – 12 > 12 – 67 > 67
25 < 3,2 < 3,2 – 10 > 10 – 60 > 60
31,5 < 3 < 3 – 9 > 9 – 53 > 53
40 < 2 < 2 – 8 > 8 – 50 > 50
50 < 1 < 1 - 7 > 7 - 42 > 42
CATEGORY A: DOES NOT CAUSE DAMAGE
CATEGORY B: POSSIBLE CRACKS OF PLESTERANT (CRACKED / SEPARED ON BORDER PEKUL WALLS
CATEGORY C: POSSIBLY DAMAGED WALL STRUCTURE COMPONENTS OF BABAN BEARING CATEGORY D: BRUSHED WALL BEARING LOADS
The principle of preventing and overcoming
disturbances of vibration and noise of mechanical systems:
PERFORMED VIBRATION ISOLATION RIGHT PLACEMENT OF EQUIPMENT
STRUCTURE BORNE
VIBRATION ISOLATION
RESILIENT MATERIAL
NEOPRENE BASE
FIBERGLAS BASE
Resilient pad
EQUIPMENT PLACEMENT
The type of isolation, the determination of the
static deflection of the insulator and the mounting support are determined by:
1. Equipment characteristics.
2. Location against critical areas.
3. Floor plate spans.
H
H Position it closer
to the structural column
Installing a vibration damper
pedestal
AIR BORNE
NOISE CHARACTERISTICS OF DUCTING SYSTEM
NOISE INTERFERENCE DUE TO TURBULENCE.
Generally occurs at the center frequency (250-2000Hz) FAN NOISE ('RUMBLE’)
Generally occurs at low frequencies <250 Hz AIR OUTLET NOISE
Generally occurs at high frequencies> 1000 Hz.
SOURCE OF NOISE IN DUCT
TURN
Sharp turns cause air flow turbulence.
Smooth curved bends will reduce turbulence.
TRANSITION
The sudden enlargement of the duct creates turbulence.
Slow, gradual <8 degrees will reduce turbulence and noise.
BRANCH
Smooth bends with a wide radius from the main duct to the branch duct will reduce turbulence. Likewise, vice versa.
CROSS TALK
Unexpected sound that is transmitted from
one room to another through the air duct that
is short of the outlet / inlet distance.
The countermeasure
Extend the distance between the outlet / inlet room / room with each other.
Cover the inner surface of the duct with fiberglass.
Using an outlet / in let layout via branches. The main duct channel in the building's hallway is then made branching into each of the building spaces.
THE IMPACT OF VIBRATION CAN BE GROUPED INTO:
The disruption of human health and comfort.
May cause damage to buildings and building components.
Shock Vibration Impact.
MANAGEMENT OF MECHANICAL VIBRATION IMPACT
• vibration source: reduces the impact, transmitted and
ballanced forces and excitation by reducing the motion at the point of contact
• propagation medium: cutting the vibration transmission path (discontinues in transmission path), dispersing energy and dissipation on the transmission medium
• vibration receiver: addition of vibration receiving & vibration isolation materials)
