Deflection Study

    
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Gravity Induced Deflection:
Determine the maximum deflection of thin Aluminum ceiling tiles in sizes of 24x24 to 48x120 inches with several perforation patterns and initial curvature under gravity loading. The panels hang from conventional "T" brackets. The contact edge is 3/8 of an inch in from the peripheral edges of each panel.

Special features:
3D model setup using 3D enhanced shell elements and trusses. Since the model will exhibit "large deflections," a nonlinear effect, use a nonlinear iterative solver. The truss element acts as the "T" bracket edge constraint. The 3D truss has no rotational degrees of freedom, so no bending moment will be transferred to the panel. The perforations present a difficulty. To mesh them explicitly results in a model with more elements than can be solved for in a reasonable amount of time, especially for the largest panels with the smallest holes. Therefore, the Elastic Modulus and density were adjusted so that simple rectangular meshes without explicit perforations could be used instead and still exhibit the desired physical stiffness and loading of the actual tile. Employ symmetry where practical to reduce the model size and computation time.

Output:
Deflection plots of the various designs.

Comments:
The Z-axis displacement animations above (click thumbnails to access) are for one size of panel with flat, concave, and convex initial shapes of three initial curvatures. The flat panel edge constraint is at 2" and not 3/8" as seen in the remaining cases. The animation parameters have been varied slightly from movie to movie to show-off some of the features within the Autodesk Algor Simulation postprocessor.