Investigation into dynamic response of a three-point bend specimen in a Hopkinson bar loaded fracture test using numerical methods

The dynamic behaviour of earthen materials reinforced with natural fibres is little studied although earth buildings are often built in seismic areas. In this paper the dynamic behaviour of an earthen material reinforced with hemp fibres under different impact loadings has been experimentally investigated. The dynamic response of the material in 3-point bending was investigated through an instrumented dropweight device, while the response in tension and in compression was investigated through a modified Hopkinson bar device. Typical impact response curves for tension, compression and bending impact tests have been obtained. The favourable effect of fibres in dissipating fracture energy under impact loads has been observed in all these types of test.

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BEM Analysis of a Cylindrical Three-Point Bend Specimen with a Chevron Crack for Fracture Toughness Test of Rock

JSME international journal Ser 1 Solid mechanics strength of materials ◽

10.1299/jsmea1988.32.3_427 ◽

1989 ◽

Vol 32 (3) ◽

pp. 427-431

Author(s):

Kazuo HAYASHI ◽

Akihiko ONO ◽

Hiroyuki ABE

Keyword(s):

Fracture Toughness ◽

Fracture Toughness Test ◽

Bend Specimen ◽

Toughness Test ◽

Point Bend

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Arcan-Richard Specimens: Is there a Pure Shear Mode?

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.452-453.345 ◽

2010 ◽

Vol 452-453 ◽

pp. 345-348

Author(s):

Stanislav Seitl ◽

Pavel Hutař ◽

Alfonso Fernández Canteli

Keyword(s):

Pure Shear ◽

Shear Mode ◽

Bend Specimen ◽

Mixed Mode Loading ◽

Tension Specimen ◽

Stress Mode ◽

Standard Specimens ◽

Finite Element Calculations ◽

Point Bend ◽

Constraint Level

Traditionally, applications of fracture mechanics have been mainly focused on cracks growing under the opening or mode I mechanism (three point bend specimen, middle tension specimen, crack tension specimen, etc.). When investigating instability under mixed mode loading conditions, three different alternatives can be envisaged consisting of: a) machining a hole in standard specimens, b) creating a crack oriented under a given angle, and c) using non-standard Arcan-Richard specimens. In this work, finite element calculations are performed to analyze the initial values of the fracture parameters in Arcan-Richard specimens. First, the influence of the normal stress mode to the shear stress mode ratio is analyzed, then the effect of the constraint level is discussed, and finally, the initial propagation angle of the daughter crack is derived.

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