Deep penetration of low velocity metal penetrators into ice

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/09544062211031605 ◽

2021 ◽

pp. 095440622110316

Author(s):

Maxim Yurievich Orlov ◽

Yulia Nikolaevna Orlova

Keyword(s):

Numerical Modelling ◽

Continuum Mechanics ◽

High Strain ◽

Computer Code ◽

Deep Penetration ◽

Strain Rates ◽

Low Velocity ◽

Crack Paths ◽

Penetration Time ◽

Model Crack

The paper summarizes the results of research of the destruction of an ice block with cylindrical and spherical penetrators at low velocity (≤325 m/s). The behaviour of ice at high strain rates is described by an elastic–plastic model of continuum mechanics. Numerical modelling of penetration is performed with IMPACT computer code. Algorithms of splitting nodes and destroying elements in a Lagrangian numerical method were modified to solve problems of penetration and perforation. The fracturing is described by a deterministic fracture model. Crack paths are examined; the damage is predicted and compared with existing experimental results. It was found that in the subsonic range of initial velocities the penetration time did not exceed 0.3 ms. Examination of the penetrators’ shapes showed that they were not plastic deformed.

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Experimental Studies of the Behaviour at High Strain Rates of Unfilled and Filled Polypropylenes

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.3-4.363 ◽

2006 ◽

Vol 3-4 ◽

pp. 363-368 ◽

Cited By ~ 1

Author(s):

N. Temimi ◽

Noelle Billon

Keyword(s):

Strain Rate ◽

High Speed ◽

High Strain ◽

Experimental Studies ◽

Young Modulus ◽

Video Camera ◽

Image Correlation ◽

Strain Rates ◽

High Strain Rates ◽

Low Velocity

Thermo mechanical behaviour of unfilled and filled polypropylenes are studied in tension from 10-4 to 102 s-1. Complementary low velocity compression and shear tests are also performed. A high-speed video camera (up to 2500 frames/s) combined with image analysis, image correlation and an infra red pyrometer allow measuring 3D-strain fields and temperature during tests. Thus, data can be processed without restrictive assumptions. Beside usual (for polymers) temperature and strain rate sensitivities it is found that plastic deformation in these materials does not obey incompressibility assumption. Voiding damage is evidenced in the polymer matrix by SEM observations that result in volume change and significant decrease in Young modulus for both materials. Moreover, an increase in the temperature of more than 10 °C is observed and is likely to modify the behaviour of each material at high strain rates. Shear and compression measurements demonstrate that yield criteria and constitutive equation depend on loading. It is concluded that apparent yield stress in semi-crystalline polypropylene can be a result of a combination of “non strain rate sensitive” “non-cohesive mechanisms” and “strain rate sensitive” “cohesive mechanisms”. Experimental characterisation on polymers should then be revisited as most of the usual assumptions are invalid and non monotonic tests should be generalized.

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Solid Solution Effects and Deformation Micros trueture of Shock-Loaded Iron Manganese Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069090 ◽

1970 ◽

Vol 28 ◽

pp. 420-421

Author(s):

A. Christou ◽

J. V. Foltz ◽

N. Brown

Keyword(s):

Solid Solution ◽

Shock Loading ◽

High Strain ◽

Local Stress ◽

Strain Rates ◽

Local Stress Concentration ◽

Bcc Metals ◽

Manganese Alloys ◽

Iron Manganese ◽

Transmission Microscope

In general, all BCC transition metals have been observed to twin under appropriate conditions. At the present time various experimental reports of solid solution effects on BCC metals have been made. Indications are that solid solution effects are important in the formation of twins. The formation of twins in metals and alloys may be explained in terms of dislocation mechanisms. It has been suggested that twins are nucleated by the achievement of local stress-concentration of the order of 15 to 45 times the applied stress. Prietner and Leslie have found that twins in BCC metals are nucleated at intersections of (110) and (112) or (112) and (112) type of planes.In this paper, observations are reported of a transmission microscope study of the iron manganese series under conditions in which twins both were and were not formed. High strain rates produced by shock loading provided the appropriate deformation conditions. The workhardening mechanisms of one alloy (Fe - 7.37 wt% Mn) were studied in detail.

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