MECH 375 | Mechanical Vibrations Lab Experiment 4
Forced Harmonic Response of a Single DoF System Concordia
University
Lab Experiment 4
Forced Harmonic Response of a Single DoF
System
Kamal Lal | 26991459
Sheanthan Selvananthan | 26980317
Section MO
Professor Waiz Ahmed
,Conducted | 2 March 2015
Submitted | 16 March 2015
, Objective
The objective of this experiment is to analyse forced harmonic response of
a SDOF torsion vibration system and understand the importance of damping in
mechanical systems.
Introduction
Forced harmonic response occurs when a system is subjected to a periodic
external force, causing it to oscillate. This motion can be undamped or damped,
depending on the composition and properties of the system. For the first part of
this experiment, an input is provided to a shaker, which is attached to one end of
a shaft. An inertial disc is mounted on the other side and the desired frequency is
applied. Sensors record the deflection at each end and convey it to an
oscilloscope; the data obtained can be used to calculate the natural frequency,
phase angle, and amplitude ratio of the system.
The amplitude ratio is the fraction of the excitation that the steady-state
amplitude consists of. It is defined by the following equation:
∣ ∣
θss
θi
= 1
√ ( ) ( )
2 2 2
ω ω
1− ωn + 2 ζωn
The phase angle is indicative of the gap between the oscillations of the excitation
and the response. To calculate this parameter, the following equation is used:
∣ ∣
Wher
e:
2ζ ω
ωn
θss = Steady-state
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller smartzone. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $11.49. You're not tied to anything after your purchase.