Static and Dynamic Behavior of Antisymmetrically Loaded Arches

R. H. Chiu · S. K. Takahashi · Stanley K. Takahashi

јан. 1966 г. · Naval Civil Engineering Laboratory

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Four pinned-base steel arches with a 96-inch radius, 143.8-inch span, and uniform cross section were cold-rolled from 4M13 sections and tested under various static and dynamic loads uniformly distributed over one-half the arc length. A maximum static load of 72,000 pounds was applied by the NCEL blast simulator using compressed air. A dynamic peak load of 64,000 pounds was attained by detonating Primacord in the blast simulator. The blast loading had a rise time of about 3 milliseconds and a decay time of about 1.6 seconds. An equivalent triangular load-time function was used for the dynamic analysis. The applied loads and the resulting deflections, strains, and reactions were measured. The reduced data are presented in graphical and tabular form. The theoretical analyses for statically and dynamically loaded arches were based on the discrete framework which represented the continuous arches tested. A 16-bar system was used for both static and dynamic response calculations, and a 40-bar system was used for natural mode and frequency calculations. In the static analysis, the effects of stress amplification, misalignment, and elastic supports on the response of the arch were considered. Due to the strain- hardening characteristics of the arch material, the idealized stress-strain curve was represented by a trilinear curve rather than by the usual bilinear stress-strain curve. A simplified dynamic analysis gave results reasonably close to those from more rigorous methods; the values were on the conservative side. Nearly complete correlation between the theoretical and experimental results was obtained.