Uncertainty Quantification of a Containment Vessel Dynamic Response Subjected to High-Explosive Detonation Impulse Loading

Different modern shell structures are exposed to impulsive loading very often. Some of them may have different imperfections such as apertures, welds, and irregular thickness. These structures can be made by static or impulsive loading. To know fractureless dynamic response of shell structures with apertures is important in many cases, especially for forming processes, because of the first appeared fracture can extend through a shell blank especially if material is brittle with low plastic properties. The tooling for impact and static loading of flat and shell structures was developed. Dynamic response of shell structures with unsupported apertures on internal impulsive loading by point high explosive charges is described. Strain state of shaped shell structures with apertures after explosive forming is shown. The limit aperture diameter for dynamic fractureless response is determined. Distributions of strain intensities on a sample cross section for different aperture diameters, static and dynamic loading are shown. Different jet engine parts were made using developed technology.

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High Speed, Localized Multi-Point Strain Measurements on a Containment Vessel at 1.7 MHz Using Swept-Wavelength Laser-Interrogated Fiber Bragg Gratings

Sensors ◽

10.3390/s20205935 ◽

2020 ◽

Vol 20 (20) ◽

pp. 5935

Author(s):

Steve Gilbertson ◽

Mark Pickrell ◽

Dario Castano ◽

Gary Salazar ◽

Tom Beery ◽

...

Keyword(s):

Strain Measurement ◽

High Speed ◽

High Explosive ◽

Fiber Bragg Gratings ◽

Bragg Gratings ◽

Laser Source ◽

Global Changes ◽

Element Analysis ◽

All Optical ◽

Explosive Detonation

Dynamic elastic strain in ~1.8 and 1.0 m diameter containment vessels containing a high explosive detonation was measured using an array of fiber Bragg gratings. The all-optical method, called real-time localized strain measurement, recorded the strain for 10 ms after detonation with additional measurements being sequentially made at a rate of 1.7 MHz. A swept wavelength laser source provided the repetition rate necessary for such high-speed measurements while also providing enough signal strength and bandwidth to simultaneously measure 8 or more unique points on the vessel’s surface. The data presented here arethen compared with additional diagnostics consisting of a fast spectral interferometer and an optical backscatter reflectometer to show a comparison between the local and global changes in the vessel strain, both dynamically and statically to further characterize the performance of the localized strain measurement. The results are also compared with electrical resistive strain gauges and finite element analysis simulations.

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Discovery of a nanodiamond-rich layer in the Greenland ice sheet

Journal of Glaciology ◽

10.3189/002214310794457191 ◽

2010 ◽

Vol 56 (199) ◽

pp. 747-757 ◽

Cited By ~ 23

Author(s):

Andrei V. Kurbatov ◽

Paul A. Mayewski ◽

Jorgen P. Steffensen ◽

Allen West ◽

Douglas J. Kennett ◽

...

Keyword(s):

High Explosive ◽

Ice Sheet ◽

Greenland Ice Sheet ◽

Impact Indicator ◽

Glacial Ice ◽

Ice Caps ◽

Very High ◽

Explosive Detonation ◽

Discrete Layer ◽

The Last Glacial

AbstractWe report the discovery in the Greenland ice sheet of a discrete layer of free nanodiamonds (NDs) in very high abundances, implying most likely either an unprecedented influx of extraterrestrial (ET) material or a cosmic impact event that occurred after the last glacial episode. From that layer, we extracted n-diamonds and hexagonal diamonds (lonsdaleite), an accepted ET impact indicator, at abundances of up to about 5×106 times background levels in adjacent younger and older ice. The NDs in the concentrated layer are rounded, suggesting they most likely formed during a cosmic impact through some process similar to carbon-vapor deposition or high-explosive detonation. This morphology has not been reported previously in cosmic material, but has been observed in terrestrial impact material. This is the first highly enriched, discrete layer of NDs observed in glacial ice anywhere, and its presence indicates that ice caps are important archives of ET events of varying magnitudes. Using a preliminary ice chronology based on oxygen isotopes and dust stratigraphy, the ND-rich layer appears to be coeval with ND abundance peaks reported at numerous North American sites in a sedimentary layer, the Younger Dryas boundary layer (YDB), dating to 12.9 ± 0.1 ka. However, more investigation is needed to confirm this association.

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