Premium
Dynamic mechanical properties of polyurethane elastomers using a nonmetallic Hopkinson bar
Author(s) -
Rao S.,
Shim V. P. W.,
Quah S. E.
Publication year - 1997
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(19971024)66:4<619::aid-app2>3.0.co;2-v
Subject(s) - split hopkinson pressure bar , materials science , composite material , elastomer , strain rate , bar (unit) , deformation (meteorology) , polyurethane , modulus , stress (linguistics) , polycarbonate , strain (injury) , physics , medicine , linguistics , philosophy , meteorology
A modified split Hopkinson‐bar apparatus, in which the striker and input/output bars are made of polycarbonate instead of metal, was used to study three typical examples of a high‐density flexible polyurethane elastomer (PORON) in sheet form. This variation of the device reduces a mismatch in impedance between the input/output bars and the specimen, thus allowing the stress in the specimen to reach a uniform state before significant engineering strain is induced. Dynamic compressive stress‐strain curves were obtained from the measured incident, transmitted, and reflected waves. This article presents the behavior of these foams as a function of strain rate; for PORON 4701‐05‐20125‐1637 under strain rates of 2.67 × 10 −3 s −1 to 4500 s −1 , the stress‐strain response can be described by a function comprising a rate‐dependent modulus and a strain‐dependent factor, while for PORON 4701‐01‐30125‐1604 and 4701‐12‐30062‐1604, only loading at high strain rates yields similar characteristics. Empirical equations were derived to characterize these mechanical properties; in addition, characteristics relating to energy‐absorption capability as well as deformation under approximately constant stress were also studied. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 619–631, 1997