5003 Lectures - Faculty of Engineering and Applied Science

E5003 - Ship Structures I 70
© C.G. Daley
in SI units:
P : N/m
Q : N
M : Nm
dx: m
To determine the equations for beam bending we
take a small section of the beam (which represents
any part) as a free body. We look at all the forces
and moments on the section and assuming that
the net force and net moment are zero (Newton!)
we derive the equations.
At this point we haven’t specified P,Q or M. They
can have any values. We will examine equilibrium
conditions and see how these result in
relationships among P,Q,M.
We start by summing vertical forces, which must
sum to zero for equilibrium;