Analysis of Simply Supported Aluminum and
Composite Plates with Uniform Loading to
Determine Equivalent Plate Ply Stack-Up
First Progress Report
10/8/2013
Thin Plate Theory
Three Assumptions for Thin Plate Theory
• There is no deformation in the middle plane of the
plate. This plane remains neutral during bending.
• Points of the plate lying initially on a normal-to-themiddle plane of the plate remain on the normal-tothe-middle surface of the plate after bending
• The normal stress in the direction transverse to the
plate can be disregarded
Material Properties and Governing Equations
Modulus of
Elasticity (E)
Thickness (h)
Poisson's Ratio (ν)
Edge Length (a)
Applied Surface
Pressure (q)
10 x 106 psi
0.250 inch
0.3
24 inch
10 psi
• wmax = α*q*a4/D
• D = E*h3/12*(1-ν2)
ANSYS Model with Mesh
Side 1
Side 1
Side
Side4 4
Side
Side2 2
Origin
Origin
Side 3
Side 3
• Due to Symmetry only a quarter of the
plate needs to be modeled
• The mesh size has an edge length of
0.75”
•Side 1 and Side 2 are constrained against
translation in the z-direction.
•Side 2 and Side 3 is constrained against
rotating in the x-direction
•Side 1 and Side 4 is constrained against
rotation in the y-direction
•The origin is constrained against motion
in the x- and y-directions
• A pressure of 10 psi is applied to the
area
Results of Aluminum Plate
• From governing equations:
wmax = 0.941399”
• From ANSYS
wmax = 0.941085”
• % Error = 0.033%
Upcoming Deadlines
• Work on Thin Plate Analysis for Composite
Plate
• Develop Composite Model in ANSYS
• Failure Criterion Methods for Composite
Stack-up