Universiti Tunku Abdul Rahman
Faculty
Department:
Unit Code and Name
Experiment No.:
Title of Experiment:
Laboratory Room No. and Name:
Experiment Duration (hour)
Number of Student per Group
Number of Student per Session
Lee Kong Chian Faculty of Engineering and
Science
Department of Mechanical and Materials
Engineering
UEME3233 Mechanical Vibrations
2/2
Experimental Modal Analysis
KB724
3 hours
5 students x 4 groups
20
Objectives (Optional)
● To measure of Natural Frequencies and Mode Shapes of an Cantilever Beam
Introduction
Experimental modal analysis, also known as modal analysis or modal testing, deals
with the determination of natural frequencies, damping ratios, and mode shapes
through vibration testing. Two basic ideas are involved:
1. When a structure, machine, or any system is excited, its response exhibits a
sharp peak at resonance when the forcing frequency is equal to its natural
frequency when damping is not large.
2. The phase of the response changes by 1800 as the forcing frequency crosses
the natural frequency of the structure or machine, and the phase will be 900 at
resonance.
Equipment and Materials
Item Description
IMC Cronos-PL
Triaxial Accelerometers
Shaker & Shaker Controller
Force Sensor
Computer
Wax
IMC Software (Bundle of Studio 5,
Wave and Famos)
ME’scope
*Item
category
Quantity estimation
E
E
E
E
E
C
1 set
1 set
1 set
1 set
1 unit
1 box
S
1 license
S
1 license
(e.g. per set/group of
student)
*Item category
SP Sample or specimen
C
Consumable
CH Chemical
1
Latest updated: 9th March 2022 (DLMSA)
W
E
S
Labware, glassware, tool, and
components
Equipment
Software
Caution Statement (Optional)
● Student has to take extra care on the handling of the data acquisition module,
accelerometer, and shaker.
Procedure
1. Setup the experiment with test structure equipped with accelerometers mounted
with designated location.
2. Connect all the accelerometers and force sensor to the selected channel.
3. Run the program IMC software and “ME ‘scope”.
4. Observe the frequency spectrum from the accelerometers.
Questions & Report Writing
● Identify the basic set up of the experimental modal test analysis
equipment/component requirement.
● Discuss the use of EMA in vibration measurement.
● Discuss the other application of EMA in industries.
● Differentiate the shaker test and impact test.
● Analyse the relation between natural frequencies and its mode shapes.
2
Latest updated: 9th March 2022 (DLMSA)