title: The high strain-rate behaviour of selected tissue analogues.
abstract: The high strain-rate response of four readily available tissue simulants has been investigated via plate-impact experiments. Comparison of the shock response of gelatin, ballistic soap (both sub-dermal tissue simulants), lard (adipose layers) and Sylgard(®) (a potential brain simulant) allowed interrogation of the applicability of such monolithic tissue surrogates in the ballistic regime. The gelatin and lard exhibited classic linear Hugoniot equations-of-state in the US-uP plane; while for the ballistic soap and Sylgard(®) a polymer-like non-linear response was observed. In the P/σX-v/v0 plane there was evidence of separation of the simulant materials into distinct groups, suggesting that a single tissue simulant is inadequate to ensure a high-fidelity description of the high strain-rate response of complex mammalian tissue. Gelatin appeared to behave broadly hydrodynamically, while soap, lard and Sylgard(®) were observed to strengthen in a material-dependent manner under specific loading conditions at elevated shock loading pressures/stresses. This strengthening behaviour was tentatively attributed to a further polymeric-like response in the form of a re-arrangement of the molecular chains under loading (a steric effect). In addition, investigation of lateral stress data from the literature showed evidence of operation of a material-independent strengthening mechanism when these materials were stressed above 2.5-3.0GPa, tentatively linked to the generically polymeric-like underlying microstructure of the simulants under consideration.
authors.affiliation: Cranfield Defence and Security, Cranfield University, DA-CMT, Shrivenham, Swindon SN6 8LA, UK. Electronic address: g.applebythomas@cranfield.ac.uk.
authors.forename: G J
authors.initials: GJ
authors.lastname: Appleby-Thomas
authors.affiliation: School of Engineering and Information Technology, The University of New South Wales, UNSW Canberra, Northcott Drive, Canberra ACT 2600, Australia.
authors.forename: P J
authors.initials: PJ
authors.lastname: Hazell
authors.affiliation: Cranfield Defence and Security, Cranfield University, DA-CMT, Shrivenham, Swindon SN6 8LA, UK.
authors.forename: R P
authors.initials: RP
authors.lastname: Sheldon
authors.affiliation: Cranfield Defence and Security, Cranfield University, DA-CMT, Shrivenham, Swindon SN6 8LA, UK.
authors.forename: C
authors.initials: C
authors.lastname: Stennett
authors.affiliation: Cranfield Defence and Security, Cranfield University, DA-CMT, Shrivenham, Swindon SN6 8LA, UK.
authors.forename: A
authors.initials: A
authors.lastname: Hameed
authors.affiliation: Department of Physics, Imperial Blast, Imperial College, London, UK.
authors.forename: J M
authors.initials: JM
authors.lastname: Wilgeroth
mesh_terms: D001696:Biomechanical Phenomena; D040761:Biomimetic Materials; D006801:Humans; D008422:Materials Testing; D013314:Stress, Mechanical