Dean, G; Wright, L (2002) Analysis of failure tests on uniaxial tensile and plate specimens of ABS. NPL Report. MATC(A)88

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Abstract

The centre-loaded plate test, described in easier reports, has been used to obtain measurements on ABS specimens at failure. Failure occurs in this test under a stress state that is equibiaxial tension. Results are compared with measurements of failure under a uniaxial tensile stress. In both of these tests, failure follows extensive plastic deformation which is promoted by the nucleation of cavities in the rubber particles.
Criteria for failure are considered which propose that a component of strain in the matrix material between cavities reaches a critical value at failure which is independent of the applied stress state. Expressions are given for the plastic volumetric strain and the effective plastic strain in the material between cavities. The results of experiments and associated data analysis are described that enable calculation of these strain components at failure in the uniaxial tension and plate tests. For this purpose, the evaluation of a new specimen geometry is described for determining properties at failure under uniaxial tension.
The results of these experiments are not sufficiently accurate to verify the use of a failure criterion based on a critical component of strain failure. However, within the bounds of the uncertainties in experimental data, the results are consistent with a criterion based on a critical value for the plastic volumetric strain in the matrix polymer between cavities.

Item Type:	Report/Guide (NPL Report)
NPL Report No.:	MATC(A)88
Keywords:	failure criteria, cavitation, rubber-toughened plastics, tensile testing
Subjects:	Advanced Materials Advanced Materials > Mechanical Measurement
Last Modified:	02 Feb 2018 13:17
URI:	http://eprintspublications.npl.co.uk/id/eprint/2400

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