Study of the Similarities in Scale Models of a Single-Layer Spherical Lattice Shell Structure under the Effect of Internal Explosion

Abstract

The similarity of each scale model is verified based on the theory of similarity, deriving the similarity law of internal explosions in a single-layer spherical lattice shell structure via dimensional theory, calculated based on models with scaling coefficients of 1, 0.8, 0.6, 0.4, 0.2, and 0.1. The results show that the shock wave propagation characteristics, the distribution of the overpressure on the inner surface, the maximum dynamic response position, and the position at which the earliest explosion venting occurs are all similar to those of the original model. With the decrease of scaling coefficients, the overpressure peak value of the shock waves of each scale model, and the specific action time of the positive pressure zone, as well as specific impulse are increasingly deviated from the original model values; when the scaling coefficient is 0.1, the maximum relative error between the overpressure peak value at the measurement point and the specific action time of the positive pressure zone as well as the specific impulse and the original model value is 4.9%. Thus, it is feasible to forecast the internal explosion effect of the original structure size model by using the experiment results of the scale model with scaling coefficient λ≥0.1.

Study on Pressure Characteristics and Its Evolution Law at the Ellipsoidal End Cover Pole of Cylindrical Explosion Containment Vessels

“…Based on previous numerical simulation studies [5,7], it was generally believed that the initial pressure stage at the end cover pole was divided into two parts: first, the explosion shock wave inside the charge was encountered at the pole and the reflected pressure was generated. Then, the convergence collision wave of the shock wave was formed at the pole, and the convergence pressure was significantly higher than the first pressure peak.…”

“…V. Pickerd et al [6], through experiments and numerical simulation, found that the second peak was much higher than the first peak, which was on the gauges at the edge and corner of the cubic explosive vessel. W. B. Wang et al [7] used numerical models with different zoom ratios to analyze the pressure load distribution of a single-layer spherical lattice shell structure, in which the maximum pressure at the pole always appeared at the second peak. Z. R. Li et al [8] experimentally measured the pressure, which was loaded on the cover plate of a cylindrical vessel, with an aspect ratio of 2:1, indicating that the pressure load on it presented multiple wave peaks, and the maximum peak of the pressure load at the center of the cover plate was three times higher than the first.…”