title: On compression and damage evolution in two thermoplastics.
abstract: The well-known Taylor cylinder impact test, which follows the impact of a flat-ended cylindrical rod onto a rigid stationary anvil, is conducted over a range of impact speeds for two polymers, polytetrafluoroethylene (PTFE) and polyetheretherketone (PEEK). In previous work, experiments and a model were developed to capture the deformation behaviour of the cylinder after impact. These works showed a region in which spatial and temporal variation of both longitudinal and radial deformation provided evidence of changes in phase within the material. In this further series of experiments, this region is imaged in a range of impacted targets at the Diamond synchrotron. Further techniques were fielded to resolve compressed regions within the recovered polymer cylinders that showed a fracture zone in the impact region. The combination of macroscopic high-speed photography and three-dimensional X-ray imaging has identified the development of failure with these polymers and shown that there is no abrupt transition in behaviours but rather a continuous range of responses to competing operating mechanisms. The behaviours noted in PEEK in these polymers show critical gaps in understanding of polymer high strain-rate response.
authors.affiliation: School of Materials , University of Manchester , Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA , UK.
authors.forename: N K
authors.identifier: 0000-0002-8883-1196
authors.initials: NK
authors.lastname: Bourne
authors.affiliation: School of Materials , University of Manchester , Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA , UK.
authors.forename: S C
authors.initials: SC
authors.lastname: Garcea
authors.affiliation: School of Materials , University of Manchester , Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA , UK.
authors.forename: D S
authors.initials: DS
authors.lastname: Eastwood
authors.affiliation: School of Materials, University of Manchester, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA, UK; Defence Science and Technology Organisation, Adelaide, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Parry
authors.affiliation: Diamond Light Source Ltd , Harwell Science and Innovation Campus , Didcot, Oxfordshire OX11 0DE , UK.
authors.forename: C
authors.initials: C
authors.lastname: Rau
authors.affiliation: School of Materials , University of Manchester , Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA , UK.
authors.forename: P J
authors.initials: PJ
authors.lastname: Withers
authors.affiliation: School of Materials , University of Manchester , Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA , UK.
authors.forename: S A
authors.initials: SA
authors.lastname: McDonald
authors.affiliation: Explosive Science and Shock Physics Division , Los Alamos National Laboratory , Los Alamos, NM , USA.
authors.forename: E N
authors.initials: EN
authors.lastname: Brown
keywords: Taylor impact; dynamic response; thermoplastic