STATIC AND DYNAMIC BEHAVIOR OF MONOTUBE SPAN-TYPE SIGN STRUCTURES. VOLUME II - APPENDICES

The report presents the results of the first major investigation into the static and dynamic behavior characteristics of monotube span-type sign structures. Detailed static and dynamic stresses and deflections have been determined fo an actual 100 ft span sign structure, utilizing 2- and 3-dimensional finite element modeling. Parametric studies have also been made, where the effects of column stiffness, beam stiffness, span, and sign location an size were examined. It is shown that in-plane and out-of-plane analyses can be conducted independently, and that stresses for tubular members can be determined by vector addition. Static in-plane deflections generally govern the design, but do not satisfy the current AASHTO requirement of d squared /400, where d equals depth of sign in feet. Structural resonance is found for a very narrow range of wind speeds, assuming no damping and sustained wind over a prolonged period. Design recommendations are made on the basis of stress and deflection computations for simple planar frames. Cambering is recommended for structures where gravity load deflections may be aesthetically undesirable. (Author)