Mechanical Properties of Wheat Grains at Compression

Abstract Hook’s law for evaluation of the modulus of elasticity of wheat grains and its general behaviour under compressive loads were studied. Whole specimens were subjected to compressive loading between metal parallel plates. The mechanical properties of grains were determined in terms of average failure strengths of grain bran and whole grain; deformation; and modulus of elasticity. The mechanical properties of very dry grains of the winter wheat Triticum aestivum L. with the moisture content of 10.3% were studied. The failure strength of grain bran was 4.43 MPa at the deformation of 10.7%, and the failure strength of whole grains was 4.88 MPa at the deformation of 13.5%. The modulus of elasticity of grains was 43.67 MPa. The apparent energy density at bran failure strength was 0.261 MJ·m−3, and 0.470 MJ·m−3 on the level of grain failure strength of the whole grain. The bran border structure of central inner part of grains was studied using microscope digital sections of longitudinal cuts of the grains using the image computer processing method. The area proportion of starch and pericarp of the border parts of grains was studied to describe the border texture of central sections of grains.