MEE-546 – Finite Element Analysis in Solid Mechanics

MEE-546 – Finite Element Analysis in Solid Mechanics
Fall 2012
Homework Assignment #7
Report a through summary of results in a professional manner by due date listed above.
Shell Problem
A large cylindrical shell is 120 inches long with a 30 inch inner radius is subjected to a
uniform internal pressure of 75 lbs/in2. It has a modulus of elasticity of 3x106 psi,
Poisson’s ratio of 0.3 and thickness of 1.25 inches. Assume the ends of the shell are
capped with a rigid plate.
Perform a finite element analysis of this shell under internal pressure only.
Study the difference in results between various element types used.
Study the influence of the meshing on results.
Verify the model. Compare the solution to the membrane solution near the center
of the shell. Compare to other appropriate theories.
5) Recommend a model that you think is most appropriate for analysis. (element
type, size ect.
6) Add a set of point loads of magnitude 1x106 pounds at the center and reanalyze.
Report stress contours and displaced shape.
120 in
60 in
2. A spherical dome is fabricated with aluminum of 75 mm thickness. Assume that the
boundary conditions are ideal so that the membrane solution applies (the support is
tangent to the shell surface at the boundary). The radius of the dome is 30 m., with an
enclosed angle, o , of 48 degrees. It is loaded with a pressure load of 8 KPa, which does
not include the weight of the aluminum.
a) Describe how you imposed the boundary conditions.
b) Plot the membrane stresses versus the angle, . Ignoring gravity load of the
c) Repeat b) including the gravity load.
d) Compare the solution above to one where the ends of the shell are clamped at the