scholarly journals Noncompressed cylindrical layer shock loading in anisothermic conditions

Author(s):  
Виктор Игоревич Штука

На примере нескольких задач о нагружении упруговязкопластического и термоупругого цилиндрических слоёв с предварительными деформациями показаны основные моменты, на которые следует обратить внимание при комплексном моделировании отклика на существенно нестационарное воздействие термоупругой несжимаемой среды с вязкопластическими свойствами. Отмечены нюансы, касающиеся употребления соотношений теории больших упругопластических деформаций, применения метода лучевых рядов и использования специальных схем численных расчётов. Представлены зависимости скачков температуры и добавочного давления на плоскополяризованных поверхностях сильного разрыва, определены скорости волн нагрузки и круговой поляризации. The main points witch should be paid attention of modeling the response of thermoelastic incompressible medium with viscoplastic properties to the essentially unsteady effect are shown by the example of several problems on loading elastoviscoplastic and thermoelastic cylindrical layers with preliminary deformations. Some remarks were noted regarding to the use of the relations of the theory of finite elastoplastic deformations, the ray series method application and special numerical calculation schemes. The dependencies of temperature and additional pressure breaks on plane-polarized strong discontinuities surfaces, loading and circular polarized waves velocities are determined.

Author(s):  
D. Faulkner ◽  
G.W. Lorimer ◽  
H.J. Axon

It is now generally accepted that meteorites are fragments produced by the collision of parent bodies of asteroidal dimensions. Optical metallographic evidence suggests that there exists a group of iron meteorites which exhibit structures similar to those observed in explosively shock loaded iron. It seems likely that shock loading of meteorites could be produced by preterrestrial impact of their parent bodies as mentioned above.We have therefore looked at the defect structure of one of these meteorites (Trenton) and compared the results with those made on a) an unshocked ‘standard’ meteorite (Canyon Diablo)b) an artificially shocked ‘standard’ meteorite (Canyon Diablo) andc) an artificially shocked specimen of pure α-iron.


Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.


Author(s):  
K. P. Staudhammer ◽  
L. E. Murr

The effect of shock loading on a variety of steels has been reviewed recently by Leslie. It is generally observed that significant changes in microstructure and microhardness are produced by explosive shock deformation. While the effect of shock loading on austenitic, ferritic, martensitic, and pearlitic structures has been investigated, there have been no systematic studies of the shock-loading of microduplex structures.In the current investigation, the shock-loading response of millrolled and heat-treated Uniloy 326 (thickness 60 mil) having a residual grain size of 1 to 2μ before shock loading was studied. Uniloy 326 is a two phase (microduplex) alloy consisting of 30% austenite (γ) in a ferrite (α) matrix; with the composition.3% Ti, 1% Mn, .6% Si,.05% C, 6% Ni, 26% Cr, balance Fe.


Author(s):  
J. A. Korbonski ◽  
L. E. Murr

Comparison of recovery rates in materials deformed by a unidimensional and two dimensional strains at strain rates in excess of 104 sec.−1 was performed on AISI 304 Stainless Steel. A number of unidirectionally strained foil samples were deformed by shock waves at graduated pressure levels as described by Murr and Grace. The two dimensionally strained foil samples were obtained from radially expanded cylinders by a constant shock pressure pulse and graduated strain as described by Foitz, et al.


Sign in / Sign up

Export Citation Format

Share Document