International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 06 | June 2019 www.irjet.net p-ISSN: 2395-0072
© 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1287
Low Cost Uniaxial Shake Table for Harmonic Excitation
Md Mohsin M Dafedar
Dept of Civil Engineering, TCE, Gadag
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Abstract - Shake table is a mechanical device that is used
to produce simple harmonic excitation or motion. It is a
uniaxial shake table, operating only in single direction, i.e. in
horizontal direction. It works on the principle of crank
mechanism where rotatory motion of the motor is converted
into linear motion of the table. Shake table has variety of
applications such as
to get earthquake simulations of test objects, to study if the
structure can survive during an earthquake and to predict
the earthquake response of a structure. In our project we
deal with only simple harmonic excitation to avoid
complexity.
Key Words: Shake table, uniaxial shake table, simple
harmonic excitation
1. INTRODUCTION
Shake table is a mechanical device that is used to produce
simple harmonic excitation or motion. In other words,
harmonic simulation can be achieved in laboratory by
using
shake table and to test the prototype and scaled model of
the structure. Shake table can also be used to study the
resonant frequencies of buildings. It is very important for
the engineers while designing a structure that the
resonant frequencies of the component part do not match
with the oscillating frequency of the vibratory parts as it
may cause violent swaying motions thereby leading to
catastrophic disasters and failure of structure. So, in order
to check this resonant frequency shake tables can be used.
Shake table is an experimental approach to understand
the various parameters and process that lead to the
prototype failure at a real time scenario. An electro-
hydraulic shaking
table is essential for higher degrees of freedom. They are
very expensive and require high maintenance and
operational costs.
The cost of a shake table depends on its size, performance
and its supporting components. Generally, the cost of a
shake table is several hundred thousand rupees and
maintenance cost are also high. From this perspective, we
have prepared a low-cost uniaxial shake table having
nearly the same features as that of a large vibration table
but with much lower cost primarily for laboratory
purpose.
2. PROBLEM STATEMENT
2.1 Problem Definition
A shake table is essential in assuring the performance of a
structure under vibrational conditions. Since, for
industrial purpose testing the structure is a very huge and
complex process as the models are large scaled. So, in any
engineering laboratory experimentation in terms of
monitoring and controlling small scaled models when
subjected to harmonic excitations becomes easier and
simpler by using a uniaxial shake table as translation is
only in the horizontal direction.
The advantages of a uniaxial shake table are:
1. It is used to test the performance of the structure during
any real-time event when subjected to excitations.
2. The shake table can be used for analyzing the structure
for various frequencies and amplitudes.
3. Provide data to validate analytical models.
4. Tests performed by shake tables are popular in areas of
earthquake engineering, structural dynamics and testing
of smart materials.
2.2 Problem Statement
The main aim of this project is to develop a low-cost
uniaxial shake table which gives simple harmonic
excitations to serve the purpose of the laboratory for
testing of structural models.
2.3 Objective of the project
The primary objective is to prepare a low-cost shake table
for laboratory purpose with all the necessary features and
demonstrating its working.
2.4 Methodology
1. A Structural model having table platform of size .3m x
.8m and ISMC sections length .9m by providing a 4 number
of roller support in order to move table in a uniaxial
direction.
2. The model is analyzed and designed in such a way that a
table platform can withstand a maximum load of 50kg
3. Estimation of the materials based on the drawings and
specifications.
4. Procuring all the necessary materials and then
fabricating and assembling them to get the final output.