ISSN:
0449-2978
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The effect of temperature and strain rate on the compressive yield behavior of polystyrene is compared with the effect of the same variables on crazing in tension. The results support the conclusion of other, more extensive work, which shows that crazing involves the same types of molecular processes as those which occur during deformation under compression and shear. An improved method of measuring compressive stress-strain curves is then described, and the compressive yield stress is also compared with an extrapolated tensile yield stress. The difference between the two is in line with concepts which assume a dependence of yield stress on the state of hydrostatic tension (or compression). It can be adequately described by the Mohr-Coulomb yield criterion. Application of this criterion also enables a theoretical stress strain curve in tension to be derived from other results in compression. Comparison of the tensile stress-strain curve so obtained with those which can be directly measured with other plastics, supports the hypothesis that crazing is favored by a marked decline in engineering stress during tensile elongation (plastic instability).
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1971.160090503
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