Modelling and experimental characterisation of the rate dependent fracture properties of gelatine gels

TY - JOUR

T1 - Modelling and experimental characterisation of the rate dependent fracture properties of gelatine gels

AU - Forte, A. E.

AU - D'Amico, F.

AU - Charalambides, M. N.

AU - Dini, D.

AU - Williams, J. G.

N1 - Publisher Copyright: © 2015 The Authors. Copyright: Copyright 2015 Elsevier B.V., All rights reserved.

PY - 2015/4/1

Y1 - 2015/4/1

N2 - The mechanical behaviour of gelatine gels as a function of test rate and gelatine concentration was determined through lubricated uniaxial compression and wire cutting tests. Similar to other reported literature, it was observed that the fracture stress and strain of the gels were strongly strain rate dependent whereas the strain rate effect was insignificant on the deformation/stiffness properties. The wire cutting tests led to values of energy release rate, Gc, being determined as a function of cutting rate. It was found that at small rates (up to 10mm/min), the value of Gc for the 10% w/w gelatine concentration was constant at an approximate value of 1.1J/m2. For higher values of test rate, Gc increased such that the log Gc versus log cutting rate data were well approximated with a line of slope equal to 0.5. An analytical model describing this behaviour is suggested which takes into account the fluid flow of the water through the polymeric porous gel structure. In addition, a numerical simulation of the uniaxial compression was performed using a poroelastic material model. The model enabled the effect of the strain rate on the stress in the solid network and the pore pressure to be determined. A failure criterion based on maximum solid stress was suggested which led to a reasonable agreement with the experimental failure stress and strain data as a function of strain rate.

AB - The mechanical behaviour of gelatine gels as a function of test rate and gelatine concentration was determined through lubricated uniaxial compression and wire cutting tests. Similar to other reported literature, it was observed that the fracture stress and strain of the gels were strongly strain rate dependent whereas the strain rate effect was insignificant on the deformation/stiffness properties. The wire cutting tests led to values of energy release rate, Gc, being determined as a function of cutting rate. It was found that at small rates (up to 10mm/min), the value of Gc for the 10% w/w gelatine concentration was constant at an approximate value of 1.1J/m2. For higher values of test rate, Gc increased such that the log Gc versus log cutting rate data were well approximated with a line of slope equal to 0.5. An analytical model describing this behaviour is suggested which takes into account the fluid flow of the water through the polymeric porous gel structure. In addition, a numerical simulation of the uniaxial compression was performed using a poroelastic material model. The model enabled the effect of the strain rate on the stress in the solid network and the pore pressure to be determined. A failure criterion based on maximum solid stress was suggested which led to a reasonable agreement with the experimental failure stress and strain data as a function of strain rate.

KW - Energy release rate

KW - Failure criterion

KW - Fracture

KW - Gelatine gel

KW - Hydrogel

KW - Hyperelasticity

KW - Poroelasticity

KW - Strain rate

UR - http://www.scopus.com/inward/record.url?scp=84921417064&partnerID=8YFLogxK

U2 - 10.1016/j.foodhyd.2014.12.028

DO - 10.1016/j.foodhyd.2014.12.028

M3 - Article

AN - SCOPUS:84921417064

SN - 0268-005X

VL - 46

SP - 180

EP - 190

JO - FOOD HYDROCOLLOIDS

JF - FOOD HYDROCOLLOIDS

ER -