5003 Lectures - Faculty of Engineering and Applied Science

E5003 - Ship Structures I 141
© C.G. Daley
Topic 14: The Moment Distribution Method with Sway
a Quadrant
Introduction
In this chapter we will
extend the application of the moment distribution
method for solving frames with sway
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In the previous chapter we dealt with beams and
frames in which joints could not translate due to
bending. In this chapter we all add the possibility of
sway motion. For simplicity we will only consider one
sway motion.
The solution of a sway
problem takes two parts. In
the first part a unit sway
sway is imposed on the
structure (call this the *
problem). The imposed motion
causes initial fixed end
moments, which relax as the
solution progresses, just as
happens with applied forces.
The force required to impose
the unit sway can be found
once the solution is found, just
like the other reactions. In the
example at left this is F*2x .
In the second problem (the 'f'
problem) the sway is
prevented, and the problem
solved.