Underwater shock

Underwater blast effects for Pentolite are given by Cole (Ref 2). Recent peak pressure measurements (Ref 9) confirm Cole s results. Cole (Ref 2) gives the following equations for the underwater shock effects of Pentolite at d 1.6... 

Ship Hull Design Spectral Analysis Underwater Shock Waves... 

Winning, Ibid 288-97(1958) (Underwater shock wave initiation of cast Pentolite)... 

Methods of measuring underwater shock waves by crusher gauges, diaphragm gauges piezoelectric gauges are thoroughly described by Cole (Ref 3) in Chapter 7. Cook (Ref 7) describes the use of a 16- to 64-frame/sec camera to measure the free surface vel produced by a shock wave at the surface, and the determination of the underwater pressure-distance curve for TNT... 

Some Japanese researchers at the Kyoto University of Medicines have developed a new method for removal of large stones (mineral deposits) in kidney and bladder by using micro-explosive charges without any surgery [118-120]. Recently, applications of underwater shock waves have been extended to various clinical therapies for example, in orthopedic surgery for bone formation [121, 122], in cancer therapy, for enhancement of chemotherapeutic effects [123] and in drug delivery [124, 125]. 

Underwater Shock Wave and Bubble Energy Equivalent Weight Ratios for... 

In recent years it has become popular to characterize the effectiveness of industrial expls in terms of their measured underwater shock and gas bubble effects (Refs 6,18 21). For example, it is claimed (Refs 6 21) that measured gas bubble energies correlate well with performance of the expl in breaking rock... 

The measurable underwater shock wave parameters, namely peak overpressure, pressure decay and shock velocity were defined in Fig 2. Actual pressure time records are similar to the idealized sketch of Fig 2, but unfortunately they are rarely as neat . Peak overpressures and time constants can be read directly from such records. Impulse (/pdt) and Energy Flux Density (const x /P2dt) require either analytical or graphical integration. Shock velocity is obtained from arrival times, ie, the time between firing of the expl charge and the start of the steeply rising pressure pulse... 

With the qualitative illustration of observable shock and bubble parameters shown in Fig 5, we can now proceed to a description of the test methods used to obtain such data. Figs 2 5 immediately suggest the use of pressure transducers to follow the pressure-time histories of underwater explns. Similarly Fig 1 (bottom portion) suggests the use of visual (photographic) techniques to obtain dimensions and positions of the gas bubbles. Indeed, these are the major techniques now used in studying underwater shock and bubble effects... 

The nomogram in Fig 8 (from Ref 17) summarizes the underwater shock effects of spherical TNT charges fired in deep water. To illustrate the use of this nomogram consider the following problem what are the underwater shock effects at 10 meters from a 1000kg spherical TNT charge The solution to this problem is obtained simply by drawing a line (as shown in Fig 8) between 1000 on the W scale and 10 on the R scale... 

Recently various computational hydro codes have been adapted to the determination of underwater shock parameters. A Lagrangian code (with artificial viscosity) augmented by a sharp shock routine was used by Sternberg Hurwitz (Ref 12) to generate the curves shown in Figs 22,23 24... 

So far we have been considering theoretical treatments of underwater shock effects. Now we turn our attention to a theoretical description of bubble motion... 

Underwater Shock Frequency Spectrum Analysis. V. Spectra of Refracted Pulses Compared with Isovelocity Shock Waves , NOLTR-66-4... 

The purpose of the present study is to establish the technique for fabricating two kinds of FGMs, i.e. Zr02/Ni with 10 layers and Zr02/Al203 systems with 5 layers, by using the underwater-shock consolidation technique mentioned above and to investigate microstructures and thermo-mechanical properties. 

Figure 1. Schematic illustration of underwater-shock consolidation assembly.

Figure 3 shows the results of EDX analyses of the two systems. Both the back electron images in (a) and Ka-line images of constitutional elements clearly indicate that the continuous compositional changes were achieved in each system. It is concluded that the FGM produced by the underwater-shock consolidation has fully densified microstructure ever3 here in an overall cross section without any discontinuity and defects. 

Zr02/Al203 and Zr02/Ni FGMs were fabricated successfully by the underwater-shock consolidation technique and they were densified fully without any cracks and warps. 

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