A new method for the determination of essential work of necking and tearing

We introduce a new technique for the determination of the material property characterizing the resistance to ductile fracture from a single tensile test on an unnotched specimen. The property known as the essential work of fracture (EWF) is usually associated with the specific energy, per unit cross...

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Bibliographic Details
Main Authors: Korsunsky, A, Kim, K, Chiu, C
Format: Conference item
Published: 2005
Description
Summary:We introduce a new technique for the determination of the material property characterizing the resistance to ductile fracture from a single tensile test on an unnotched specimen. The property known as the essential work of fracture (EWF) is usually associated with the specific energy, per unit cross sectional area, consumed during ductile fracture in a double edge notched tensile (DENT) specimen. This energy is referred to as 'essential' in order to distinguish it from the non-essential energy consumed on distributed plastic deformation accompanying fracture, but not required for material separation. In the present study we consider tensile tests carried out on unnotched dog-bone (DB) tensile specimens carrying large numbers of markers and incorporating continuous measurement of elongation between any two markers using a laser scanning extensometer. In a single test it is therefore possible to obtain multiple load-elongation curves for a large number of tensile specimens. This data is analyzed by separating contributions to specimen elongation made by distributed (pre-softening) and localized (post-softening) plastic deformation. We demonstrate on a series of tests the evaluation of essential and non-essential work of necking and tearing for an aluminum alloy subjected to different heat treatments, and compare the results with those obtained from conventional DENT tests.