Response to Blast Loading of Gate of Dry Dock 1 of the Long Beach Naval Shipyard

摘要

The results of a theoretical study of the response of dry dock gate structures to nuclear blast loads are presented. The gate is transformed into an equivalent spring and mass system with a single degree of freedom and no structural damping. A numerical solution to the equation of motion is used. A step-by-step outline of the damage assessment of a dry dock gate is developed. Methods to determine the mass and the stiffness distributions are included along with the parameters necessary to define the pressure-time curve for explosions in the air. A criterion for determining the amount of damage incurred by a gate is defined as a function of the gate deflection when first yielding occurs. An analysis of Gate No. 1 at Long Beach Naval Shipyard is made, including calculations. The Long Beach Gate is found to be capable of withstanding more than 20 psi overpressure under air blast loading and more than 7 psi-seconds water shock impulsive load, and still be operable after repair. Numerous nuclear environments can be defined from the knowledge of the maximum overpressure for any particular gate. (Author)