Examples

• Geometrically doubly symmetric I-beam.

• Fixed length of web and flanges.

• Fixed number of plies in walls.

• Ply angles in walls are treated as discrete variables with 15^o angle increment.

• Antisymmetric angle ply layup in the web.

• Non-symmetric angle ply layup in both flanges.

• No beam symmetry with respect to horizontal centroidal axis.

This layup produces maximal bending beam stiffness. Axial, torsional and lateral bending beam stiffnesses are required to be higher than the corresponding beam stiffnesses of the geometrically equivalent aluminum beam. Effective wall stiffnesses are required to be higher than two times the transverse ply stiffness.
 

Bottom flange layup: [0₆/45/-45]
Web layup: [45/-45/0₂]_as
Top flange layup: [45/-45/0₂/15/0/-30/-15]

Bottom flange layup: [0₂/15/-15/0₂/90/-45]
Web layup: [45/90/0₂]_as
Top flange layup: [45/90/0₃/-15/0₂]