Models of high velocity impact phenomena

Wingate, C.A.; Stellingwerf, R. F.; Davidson, R.F.; Burkett, Michael W.

doi:10.1016/0734-743x(93)90075-i

Cited by 19 publications

(4 citation statements)

References 8 publications

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“…If this is extrapolated to 450 km/s, the ratio of ejected volume to impactor volume is 2.6 × 10 4 . Measurements by Wingate et al [] of iron onto copper and aluminum at velocities up to 24 km/s found a ratio of crater volume to projectile mass of 145. Again, this extrapolates to a large ratio, 5 × 10 4 , of ejected material at 450 km/s.…”

Section: Impact Physics—laboratory Measurements and Simulationsmentioning

confidence: 99%

Dust impact signals on the wind spacecraft

2016

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We analyze waveforms recorded by the Time Domain Sampler of the WAVES experiment on Wind which are similar to impulsive waveforms observed by the S/WAVES experiment on STEREO. These have been interpreted as dust impacts by Meyer‐Vernet et al. and M. L. Kaiser and K. Goetz and extensively analyzed by Zaslavsky et al. The mechanism for coupling the emission to the antennas to produce an electrical signal is still not well understood, however. One suggested mechanism for coupling of the impact to the antenna is that the spacecraft body changes potential with respect to the surrounding plasma but the antennas do not (the body mechanism). Another class of mechanisms, with several forms, is that the charge of the emitted cloud interacts with the antennas. The Wind data show that both are operating. The time domain shapes of the dust pulses are highly variable but we have little understanding of what provides these shapes. One feature of the STEREO data has been interpreted as impacts from high velocity nanoparticles entrained by the solar wind. We have not found evidence for fast nanodust in the Wind data. An appreciable fraction of the impacts observed on Wind is consistent with interstellar dust. The impact rates do not follow a Poisson distribution, expected for random independent events, and this is interpreted as bunching. We have not succeeded in relating this bunching to known meteor showers, and they do not repeat from 1 year to the next. The data suggest bunching by fields in the heliosphere.

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Section: Impact Physics—laboratory Measurements and Simulationsmentioning

confidence: 99%

Dust impact signals on the wind spacecraft

2016

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“…Experimental data taken from Refs. [33][34][35], see also additional material in the Supplemental Material [16]. Our simulation results have been taken for clusters of a fixed size N ¼ 13, N ¼ 1000, and N ¼ 10 000 with varying velocity, and for a fixed velocity v ¼ 5:5 or 6 km=s for clusters with varying size, N ¼ 1 Â 10 3 -7:4 Â 10 6 .…”

Section: Fig 1 (Color)mentioning

confidence: 99%

Why Nanoprojectiles Work Differently than Macroimpactors: The Role of Plastic Flow

et al. 2012

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Atomistic simulation data on crater formation due to the hypervelocity impact of nanoprojectiles of up to 55 nm diameter and with targets containing up to 1.1×10(10) atoms are compared to available experimental data on μm-, mm-, and cm-sized projectiles. We show that previous scaling laws do not hold in the nanoregime and outline the reasons: within our simulations we observe that the cratering mechanism changes, going from the smallest to the largest simulated scales, from an evaporative regime to a regime where melt and plastic flow dominate, as is expected in larger microscale experiments. The importance of the strain-rate dependence of strength and of dislocation production and motion are discussed.

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“…Careful investigation would probably support similar conclusions regarding the copper data. The "data plateaus" have commonly been attributed to phase change effects (5). This work does not refute this or other explanations for the "data plateaus," but simply shows that strain-rate effects and the expected error in the data are sufficient to explain the "data plateaus.…”

Section: Computational Overviewmentioning

confidence: 49%