Joint International Conference on Long-term Experiments ...

obscured. It has been stated that relative density is the dominant physical character
representing the three-dimensional structure of cellular solids, and it has been used in many
studies, including those of biological materials(Warbuton et al., 1990), to quantify the
dependence of mechanical properties on structure.
4.2. Predicting crumb properties with little or no imaging information
Information on the volume fractions of the individual phases can be obtained from imaging
data, but it is more readily gained from density measurements. The distribution of phases
within the crumb may be irregular (Fig. 1), but statistical homogeneity
Fig. 4. Illustration of statistical homogeneity in bread crumb. Thresholded
images are one-eighth sections taken from different regions of Fig. 1. Exact
structures are different, but statistical homogeneity is
apparent.
within the bread crumb is assumed. This refers to instances where a subregion of crumb can
be selected whose volume fractions and properties are essentially the same as those of the
bread crumb specimen as a whole, even though the actual connectivities may be different.
An illustration of statistical homogeneity in bread crumb is given in Fig. 4.
CONCLUSIONS
As for other composite cellular solids, density exerts a strong influence on the mechanical
properties of bread crumb. With information on the physical properties of the solid phase of
bread crumb, it is possible from a knowledge of bread crumb density to define a range of
modulus values which the bread crumb will definitely possess. Quantification of additional
structural information by image analysis will permit improvements in predictive capacity.
To take better advantage of models used for predicting the physical properties of industrial
and biomedical cellular solids from their structure, precise and systematic measurements of
the mechanical properties of breads created from various raw materials and processing
conditions is advocated.
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