Response of SDF Systems to Extreme Overpressure

Abstract

Charts are provided for the rapid estimation of the response of an elastoplastic single-degree-of-freedom system to a decaying exponential load. The integral of the load was equated to the overpressure impulse from either the HULL code or the Speicher-Brode representation of blast wave overpressures. Plots were thus derived of the scaled duration and of the exponential characteristic parameter as a function of overpressure. Variations in both positive overpressure impulse and positive phase duration are well within the overpressure uncertainty for the scaled heights-of-burst of interest over the pressure range considered. A parametric response chart of the system is provided, which covers a very wide range of displacements, fundamental periods, and loading pressures. The chart is a graph of the results of the solution of 750 individual cases using the Newmark beta method of numerical integration.