Author | How, Liew Keng |
Call Number | AIT Thesis no.ST-87-16 |
Subject(s) | Vibration (Aeronautics)--Damping
|
Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
Publisher | Asian Institute of Technology |
Abstract | The optimum vibration isolation system for the turbo- generator of a
thermal power plant is investigated. Horizontal and vertical forces
resulting from the unbalanced mass of the rotating parts under normal
operation condition are considered. The design variables of the
isolation system are the vertical stiffness of helical springs and the
mass of an inertia block rigidly attached to the turbo-generator set.
The optimum vibration isolation system is determined with the goal to
minimize the disturbances from the turbo-generator set. Different types
of objective functions are discussed and optimization is carried out
taking into account the relevant constraints and serviceability limit
states. Various lumped-mass models are formulated for vertical, and
coupled horizontal and rocking vibrations. The investigation has been
carried out for two different types of helical springs. The optimum
solution is found by direct method. It is found that damping is
undesirable for optimum vibration isolation. The ideal vibration
isolation system is one in which either the mass of the inertia block is
very large and/or the stiffness of the isolators is very small; the
optimum, however, depends on the constraints imposed. The optimum
isolation system for the turbo-generator set analysed can reduce the
force transmissibility at the operation frequency by a factor of 105 as
compared with the existing system. |
Year | 1987 |
Type | Thesis |
School | School of Engineering and Technology (SET) |
Department | Other Field of Studies (No Department) |
Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
Chairperson(s) | Wireland, Martin
|
Examination Committee(s) | Hasegawa Akio ;Chauhan, Roshan Lal
|
Scholarship Donor(s) | Lee Foundation, Singapore |
Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1987 |