Building an aviary
A request came from Switzerland to build an extra-large aviary. Extrapolating from other aviaries seemed irresponsible, so a structural calculation was requested, along with the question of whether, within limited dimensions, anything general could be said in parametric form about the required member sizes for aviaries of any size.
This has been done. Important variables turn out to be the play at the corner of the beam-to-column connection and the rotational stiffness of that connection. The column sizes are determined by buckling under vertical load and by horizontal wind load. Naturally, the wind load increases considerably if parts of the aviary are closed in with panels. Both design criteria depend on the height of the unbraced part of the columns.
For longer spans, the deflection of the roof beams is the governing design criterion for their sizing. Deflection decreases proportionally as the spacing of the frames is reduced. The load-bearing capacity of the wire mesh, which also acts as bracing diagonals, was also included in the capacity of the structure. Because torsion is carried by each frame, it does not limit the maximum length of the structure. That length is, however, governed by thermal stresses, unless expansion joints are used. Avoid corrosion.
Contact between different metals can cause corrosion.