Use of the Velocity Intensity Spectrum to Characterize Transient Data

This paper introduces and develops the Velocity Intensity Spectrum as an analytical tool for examining transient data in the frequency domain. The Velocity Intensity Spectrum is then compared with three common alternatives: the Shock Response Spectrum, the Pseudo Velocity Spectrum, and the lesser-known Shock Intensity Spectrum, upon which it is based. The various techniques are applied to an experimental data set and compared and discussed in a practical manner.

Explosion Shock Measurement System of the Precursor Warhead for the Tandem Projectile

This paper presents a system that measures the acceleration of the shock caused by the explosion of the precursor warhead for the tandem projectile. The proposed system, which is implemented based on the MIL-STD-810G, Method 517.1, consists of a miniaturized shock measurement device, a cable, accelerometers, and a trigger circuit. The shock measurement device has a size of ￠102 x 171 mm and cable has a length of 3 m. The operational confirmation test is conducted by implementing the measurement system. The Analysis of shock data(accelerometer output data) is carried out using Shock Response Spectrum(SRS), pseudo velocity and plot of acceleration time transient. Through measurement analysis, one can predict the damage of electronics in projectile when precursor warhead is exploded.

Aspects of Strength Testing of Tank Containers in Compliance with the Requirements of the UN Navigation Rules and Regulations

This article deals with the method of computer-aided studies of the results of tank container impact tests to confirm the ability of portable tanks and multi-element gas containers to withstand the impact in the longitudinal direction on a specially equipped test rig or using a railway flat car by impacting a flat car with a striking car, in compliance with the requirements of the UN Navigation Rules and Regulations. It is shown that the main assessed characteristic of the UN requirements is the spectrum of the shock response (accelerations) for the interval natural frequencies of the shock pulse. The calculation of the points of the shock response spectrum curve based on the test results is reproduced in four stages. A test configuration of the impact testing of the railway flat car with a tank container is presented, and the impact is performed in such a way that, under a single impact, the shock spectrum curve obtained during the tests for both fittings subjected to impact repeats or exceeds the minimum shock spectrum curve for all frequencies in the range of 2 Hz to 100 Hz. Formulas for determining the relative displacements and accelerations for the interval natural frequencies of the shock wave are given. The research results are presented in graphical form, indicating that the experimental values of the shock response spectrum exceed the minimum permissible values; the equation of the experimental curve of the shock response spectrum in the frequency range 0–100 Hz is described by power-law dependence. The coefficients of the equation were determined by the statistical method of maximum likelihood with the determination factor being 0.897, which is a satisfactory value; a comparative analysis showed that the experimental curve of the impact response spectrum in the frequency range 0–100 Hz exceeds the normalized curve, which confirms compliance with regulatory requirements. A new test configuration is proposed using a tank car with a bulk liquid, the processes in which upon impact differ significantly from other freight wagons under longitudinal impact loads of the tank container. The hydraulic impact resulting from the impact on the tank container and the platform creates an overturning moment that causes the rear fittings to be unloaded.