DEFLECTIONS, VIBRATIONS, AND STABILITY OF A PAIR OF LEANING ARCHES

A structure consisting of two arches leaning against each other and at tached at their crowns is considered. Such structural units are used i n bridges and in frameworks for tents. Their three-dimensional elastic behavior is examined for six types of loads: a concentrated vertical load at the crown, a uniformly distributed vertical load applied over the whole structure or over half of it, a wind load, and uniformly dis tributed loads acting parallel to the ground and approaching either ob liquely or from the side. The arches are semicircular and pinned at th e base, and their deflections, vibrations, and stability are investiga ted for several tilt angles with the use of the finite-element method. Buckling at a bifurcation point occurs for some of the cases involvin g vertical loads. On the other hand, the two arches may contact each o ther away from the crown as the load is increased, which reduces the l ikelihood of instability.