STRAIN‐WAVE SHAPES IN ROCK NEAR EXPLOSIONS

Geophysics ◽  
1953 ◽  
Vol 18 (2) ◽  
pp. 310-323 ◽  
Author(s):  
Wilbur I. Duvall
Keyword(s):  
Rise Time ◽  
Pulse Width ◽  
Pressure Pulse ◽  
Solid Medium ◽  
Applied Pressure ◽  
Elastic Media ◽  
Strain Wave ◽  
Wave Pulse ◽  
Time Pulse ◽  
Wave Shapes

The shapes of displacement, velocity, acceleration and strain‐wave pulses in solid elastic media near a spherical cavity in which the applied pressure pulse is of the general form [Formula: see text] have been calculated. The computed strain‐wave pulse shapes at various distances from the cavity are compared with typical experimentally recorded strain‐wave pulses and are shown to have similar characteristics. The shapes of the wave pulses, that is, the rise time, pulse width, etc., are shown to be functions of the applied pressure pulse, the distance from the cavity and the properties of the solid medium.

scholarly journals Research of the anti-resonance pulse forming network and its application in the Marx generator

2016 ◽  
Vol 34 (4) ◽  
pp. 675-686 ◽  
Author(s):  
Z.-L. Pan ◽  
J.-H. Yang ◽  
X.-B. Cheng
Keyword(s):  
Equivalent Circuit ◽  
Rise Time ◽  
Pulse Width ◽  
Marx Generator ◽  
Full Width ◽  
Half Maximum ◽  
Compact Structure ◽  
Fall Time ◽  
Pulse Forming Network ◽  
Load Pulse

AbstractAn anti-resonance pulse forming network (PFN) has been designed, analyzed, and tested for its application in generating quasi-square pulses. According to the circuit simulations, a compact generator based on two/three-section network was constructed. Two-section network is applied in the generator due to its compact structure, while three-section network is employed for generating pulses with higher quality. When two-section network is applied in the generator, the full-width at half-maximum of the load pulse is 400 ns, at the same time, its rise time, flat top and fall time are 90, 180 and 217 ns, respectively. When the three-section network is applied with the same pulse width of the load pulse, the rise time of the output decreases to 60 ns, while the flat top increases to 240 ns and the fall time reduces to 109 ns. Meanwhile, this kind of network could be used to shape the output pulses of generators whose equivalent circuit is LC series discharge network, such as MARX generator, into quasi-square pulses. And the preliminary experiment demonstrates that anti-resonance network could work well on four-stage Marx generators. A sine pulse generated by the four-stage Marx generator is shaped into a quasi-square pulse with voltage of 11.8 kV and pulse width about 110 ns based on two-section anti-resonance network.

Use of a liquid shock tube as a device for the study of material deformation under impulsive loading conditions

2004 ◽  
Vol 218 (1) ◽  
pp. 39-51 ◽  
Author(s):  
B W Skews ◽  
O E Kosing ◽  
R J Hattingh
Keyword(s):  
Shock Tube ◽  
Deformation Process ◽  
High Speed ◽  
Pressure Pulse ◽  
Applied Pressure ◽  
Impulsive Loading ◽  
High Speed Photography ◽  
Material Deformation ◽  
Metal Plates ◽  
Versatile Tool

The deformation of metal plates and tubes achievable through the use of liquid shock waves generated in a shock tube is studied, with reference to both free-forming and forming the metal into dies, as well as to imprinting detailed features. The process is highly controllable, in terms of the magnitude and duration of the applied pressure pulse. A projectile is fired into a liquid column producing a high-pressure liquid shock wave which impinges on the testpiece. Different projectile materials, driving pressures and impact velocities are used to alter the energy and impulse transmitted. A particular attraction of its use in a laboratory is the application of high-speed photography to the deformation process. Illustration of the application of the facility to slamming studies and to fracture of brittle materials is included. It is concluded that the techniques employed offer a useful and versatile tool for many studies of material deformation.

Midlatency respiratory-related somatosensory activity and perception of oral pressure pulses in normal humans

2001 ◽  
Vol 90 (6) ◽  
pp. 2048-2056 ◽  
Author(s):  
J. Andrew Daubenspeck ◽  
Harold L. Manning ◽  
John C. Baird
Keyword(s):  
Evoked Potentials ◽  
Pressure Pulse ◽  
Applied Pressure ◽  
Normal Subjects ◽  
Magnitude Production ◽  
Global Field Power ◽  
Oral Pressure ◽  
Pressure Pulses ◽  
Standard Pressure ◽  
The Right

A direct relationship exists within subjects between midlatency features (<100 ms poststimulus) of respiratory-related evoked potentials and the perceived magnitude of applied oral pressure pulse stimuli. We evaluated perception in 18 normal subjects using cross-modality matching of applied pressure pulses via grip force and estimated mechanoafferent activity in these subjects by computing the global field power (GFP) from respiratory-related evoked potentials recorded over the right side of the scalp. We compared across subjects 1) the predicted magnitude production for a standard pressure pulse and 2) the slope (β) and 3) the intercept (INT) of the Stevens power law to the summed GFP over 20–100 ms poststimulus. Both the magnitude production for a standard pressure pulse and the β showed an inverse relationship with the summed GFP over 20–100 ms poststimulus, although there was no relationship between INT and the summed GFP. This may partially reflect characteristics of the mechanosensors and surely includes aspects of cognitive judgment, because we found and corrected for a high correlation between, respectively, β (and INT) for pressure pulses and β (and INT) for estimation of line lengths, a nonrespiratory modality. The relatively shallow, even inverse GFP-to-perception relationship suggests that, despite marked differences in the magnitude of afferent traffic, normal subjects seem to perceive things similarly.

Application of square wave pulse-width-variable laser using temporal shaping

2004 ◽  
Author(s):  
Li Wang ◽  
Yu Zhao ◽  
Yong Tian ◽  
Jinfeng Zhou ◽  
Liu Huang
Keyword(s):  
Pulse Width ◽  
Wave Pulse ◽  
Square Wave
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