Modelling indentation of bread crumb by finite element analysis

Finite element analysis (FEA) has the potential for shedding light on the complex mechanical behaviour of many food products. In this paper, the *HYPERFOAM material model in the ABAQUS/Standard FEA package was applied to study the mechanical properties of the crumb of white bread loaves. The applicability of this material model was validated by uniaxial compression stress-strain data. Overall stress-strain curves of low-density bread crumb were well predicted by FEA; altering Poisson's ratio in the simulations (0 and 0.21) made little difference unless the strain was greater than 0.35 for denser crumbs. Experimental compressive Young's modulus and critical stress were well correlated to their counterparts predicted from the FEA material constants in the Ogden strain energy function. The crumb, with characteristics defined by the compressive material constants, was meshed by four-node axisymmetric continuum elements of uniform size to simulate indentation of the crumb. Two cylindrical flat-ended and two spherical indenters were modelled as *RIGID SURFACE. With the axisymmetric indentation FEA model, the load-displacement curves generated from cylindrical indentation were well predicted, whereas those from spherical indenters were under-predicted. (C) 2003 Silsoe Research Institute. All rights reserved. Published by Elsevier Science Ltd.