STRUCTURAL RESPONSE OF SPINE VEHICLES. VOLUME 2. SIMULATION OF TRANSIENT SURFACE LOADS BY EXPLOSIVE BLAST WAVES
Technical rept. 4 Dec 1965-15 Sep 1966
STANFORD RESEARCH INST MENLO PARK CA POULTER LABS
Pagination or Media Count:
Techniques are described for simulating blast-type transient surface loads of nearly exponential pulse shape having characteristic times impulse peak pressure ranging from 10 to 1000 microsec the quasi-impulsive range for cylindrical shells about 1 foot in diameter. Pressure-time histories are measured at various positions around and along cylindrical models 3.5, 6, and 12 inches in diameter. A basic set of loads is obtained consisting of two limiting pressure distributions, an asymmetric distribution typical of side exposure to a normally incident blast wave, and a symmetric distribution typical of nose-on exposure. All of the loads are obtained using sheet explosive charges of various forms, from flat to semicylindrical to completely cylindrical surrounding the model and flat charges suspended at various standoffs in a shock tube. In support of the experiments, the self-similar solutions for blast waves from intense explosions are used to calculate the range of sheet charges needed to produce loads of interest and to show that the corresponding spherical charges become much too small and much too large for practical application near the extremes in load duration. Approximate formulas are also derived the Korobeinikov theory for the variation of peak pressure with distance from plane, cylindrical, and spherical charges. The range of validity of the formulas extends from high pressures, where the self-similar solutions are valid, to acoustic shock pressures. Experimental measurements from the present program and from compiled blast data show excellent agreement with the theory over the entire range.
- Test Facilities, Equipment and Methods
- Fluid Mechanics