5003 Lectures - Faculty of Engineering and Applied Science

E5003 - Ship Structures I 219
© C.G. Daley
Plates can bend in 3 ways;
• x-bending
• y-bending
• twist
X and y bending are similar to beam bending.
Recall that there are no membrane stresses,
therefor no x and y stresses at the mid-plane.
Stresses only arise from bending, and are equal,
opposite and maximum on the bottom and top of
the plate.
Twist is a behavior that does not occur in beams,
although it is something like torsion.
Twist causes a shear strain in the top (and bottom)
of the plate, and results in curvature on 45°
diagonals. When we twist a dx x dy portion of a
plate we get;
therefore
Δ =