The influence of network architecture on the large deformation and fracture behavior of emulsion-filled gelatin gels

Explosive loading techniques are applied to expand tubular cylinders, spherical shells and rings of 304 stainless steel to fragmentation, and the effects of wall thicknesses, explosive driver diameters and the constant proportionality of the in-plane biaxial stretching rates are investigated on the deformation and fracture behavior of three basic structures experimentally and numerically. In the cylinder tests, the driver is a column of high explosive PETN, inserted coaxially into the bore of a cylinder and initiated by exploding a fine wire bundle at the column axis using a discharge current from a high-voltage capacitor bank. In case of the ring tests, ring specimens are placed onto a single cylinder filled with the PETN as a expansion driver, and for sphere tests, specimens filled with the PETN are also initiated by exploding a fine copper wire line with small length located at the central point. Two types of experiments are conducted for every specimen and test condition. The first type uses high speed cameras to observe the deformation and crack generation of expanding specimens showing the final maximum in-plane stretching rate of above , and the second uses soft capturing system recovering typically most fragments successfully. The fragments are measured and investigated using a fragmentation model. The effects of test parameters on the deformation and fracture behavior for three types of structures are discussed in need of modified fragmentation model for shell structural elements.

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Dynamic Deformation and Fracture Behavior of Zr-Based Bulk Metallic Glasses

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.345-346.629 ◽

2007 ◽

Vol 345-346 ◽

pp. 629-632

Author(s):

Dong Geun Lee ◽

Yang Gon Kim ◽

Byoung Chul Hwang ◽

Sung Hak Lee ◽

Nack J. Kim

Keyword(s):

Compressive Stress ◽

Fracture Behavior ◽

Dynamic Deformation ◽

Dynamic Properties ◽

Shear Bands ◽

Total Strain ◽

Maximum Compressive Stress ◽

Amorphous Phases ◽

Deformation And Fracture ◽

Dynamic Compressive Test

Dynamic deformation and fracture behavior of Zr-based bulk metallic glass (BMG) and BMG composite containing dendritic β phases was investigated in this study. Dynamic compressive test results indicated that both maximum compressive stress and total strain of the BMG and BMG composite decreased with increasing test temperature because shear bands could propagate rapidly as the adiabatic heating effect was added at high temperatures. Above the glass transition temperature, total strain decreased more abruptly due to crystallization of amorphous phases. Maximum compressive stress and total strain of the BMG composite were higher than those of the BMG because β phases played a role in forming multiple shear bands. The BMG composite having more excellent dynamic properties than the BMG can be more reliably applied to the structures or parts requiring dynamic properties.

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