Analysis of Thermal Energy Distribution from Low Yield Nuclear Explosions

This study is dedicated for the determination of the distribution of thermal energy resulted from different types of a 50-70 KT yield nuclear explosion; surface, aerial, in different locations away from the explosion center and considering the differences in the transmittance factor and visibility conditions that may affect the distribution of thermal energy. The results showed that the majority of released thermal energy occurs during a very short period of time after explosion, and reaches its maximum of 22 KT after about 3.1 sec. Also, it was determined the absence of significant effect for the visibility degree on the value of the total thermal exposure for both types of explosions, and that the thermal exposure due to the surface explosion is about 60% of its value in case of the aerial explosion.

Influences of the Cloud Shape of Fuel-Air Mixtures on the Overpressure Field

This paper presents an experiment system in the open field, which comprises a charge structure (approximately 166.2 kg), a high-speed camera subsystem, and a pressure measurement subsystem. Through a series of experiments under the cylindrical clouds with different diameters, heights, and diameter-to-height ratios (D : H), the influences of various cloud shapes on the overpressure field were analyzed and discussed. Based on the experimental results, the overpressure field was divided into two zones: detonation wave zone and shock wave zone. It is found that the overpressure of shock waves at the same distance from the explosion center increased with the diameters, but the variations of heights had little impact on the overpressure. Therefore, the pancake-shaped cloud of fuel-air mixtures is the optimal shape for obtaining the wider overpressure field. Moreover, it is found that the overpressure field gets the maximum under the diameter-to-height ratios of 5.7 in the same distance within the studied range.

Experimental Study on the Pressure Characteristics of Gasoline Vapor Explosion under Weak Restrictions

In this paper, the pressure characteristics of gasoline vapor explosion under weak restrictions was investigated experimentally. The experimental studies have shown that explosion pressure maximized when Rs/R0 was in the range of 1.5~2.0, and when Rs/R0 > 1.5, pressure was proportional to the 2.45 power of the initial radius, and attenuated with the extended distances from the explosion center according to the rule of negative exponent.

Numerical Simulation on the Dynamic Response of Buried Pipelines Subjected to Blast Loads

When the shock wave caused by explosion in geotechnical medium encountered buried pipeline, the buried pipeline may be destroyed. Use the LS-DYNA program to describe the deformation of buried pipelines under explosion ground shock. The results indicate that the process of the stress on pipe is instantaneous, and the back of buried pipelines against explosion center suffers greater instantaneous pulling stress in axis direction. The stress on the pipes, which is brought by the weaponary explosion, is involved with the distance between the pipe and explosion center and the diameter of pipe, among which the former involves greater. And the smaller pipe would get greater shock.

Investigations on Broken Rules of the 20# Cylindrical Steel Shell under Inside-Explosion Loading

Broken rules of cylindrical steel shell subjected to internal blast loads is the foundation for conducting safety assessment and failure analysis of explosion containment vessels. The experiments were carried out broken rules of the cylindrical steel shells subjected to internal blast loadings at the centers. The elastic-plastic response of cylindrical steel shells was conducted using nonlinear dynamic finite element analysis code LS-DYNA. The results show that the deformation was’t a discrepancy in the explosion center of the cylindrical steel shell in same space, and the deformation descended slower along with thickness augmentation in the end of explosion center. The radial stress、hoop stress and axial stress was a discrepancy in the thickness way of cylindrical steel shell of explosion center The most leading cause of destructivity of cylindrical steel shell was that inner wall bearing normal stress and exterior wall bearing tensile stress; the hoop stress was broken more than axial stress cylindrical steel shell. The whole process was presenting hoop fractured and axial growth.