Premium
MECHANICS OF FAILURE IN FRUITS AND VEGETABLES
Author(s) -
HOLT J. E.,
SCHOORL D.
Publication year - 1982
Publication title -
journal of texture studies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.593
H-Index - 54
eISSN - 1745-4603
pISSN - 0022-4901
DOI - 10.1111/j.1745-4603.1982.tb00879.x
Subject(s) - slip (aerodynamics) , cleavage (geology) , structural engineering , shear stress , shear (geology) , materials science , forensic engineering , engineering , composite material , fracture (geology) , aerospace engineering
An understanding of mechanical failure in fruits and vegetables is essential to the reduction of damage in processing, handling and transport operations and to the evaluation of textural characteristics of foods. This paper proposes a theory of failure for solid horticultural materials based on the classification of failure as cleavage, slip or bruising. For each of these three modes of failure, the role of intensity of loading or stress in initiating failure is described. It is shown that cleavage is a normal stress phenomenon and that slip and bruising are shear stress phenomena. The mechanical properties of horticultural produce are described in terms of cleavage strength, slip strength and bruising strength; properties which may vary with ripening and loading conditions. A failure diagram is constructed by superimposing strength boundaries on the normal and shear stress axes of the Mohr's circles representation of the applied stress state. This novel diagram is shown to apply to selected fruits and vegetables. The model can be extended to include buckling. It is shown that horticultural materials do not fail according to one failure criterion alone, but fail, on a rising load, according to the current strength boundary first encountered by an expanding stress state. Potatoes, for example, may fail by cleavage, slip or bruising, depending on the loading conditions.