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The elastic, anelastic and plastic components of strain in the load‐extension curve for bisphenol‐A polycarbonate
Author(s) -
Robertson Richard E.,
Patel Ashwin M.
Publication year - 1972
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760120506
Subject(s) - polycarbonate , materials science , composite material , ductility (earth science) , yield (engineering) , elongation , ultimate tensile strength , elastic modulus , plasticity , strain (injury) , stress (linguistics) , creep , medicine , linguistics , philosophy
A procedure has been developed for analyzing the elongation of a specimen in a tensile test for the elastic, anelastic, and plastic components of strain. The procedure was applied to bisphenol‐A polycarbonate, which showed the division between the anelastic and plastic components to be justified and gave the following results. First, the elastic modulus was found to be essentially constant, independent of stress up to at least 7,000 psi. Second, the strain accumulated at the yield point was found to be mainly anelastic and recoverable with release of the stress. Third, plastic or non‐recoverable strain was mainly accumulated only beyond the yield point. These latter two results suggest that anelasticity is important for ductility. The relatively large anelastic response at low stresses that contribute to the ductility of polycarbonate probably arises from both the large size of the moving segment and the large low temperature loss process.