Determination of macromechanic parameters of grapes and tomatoes

The force—deformation curve was measured by the compression test of tomatoes and grapes. The mechanic characteristics of grapes and tomatoes under different stiffness and the relationships between stiffness and deformation when compressed from both transversal and longitudinal were gained under the circumstance of the same loading rates. The fruit skin tensile test from both transversal and longitudinal were carried out and the relationships between elastic modulus and strains were determined. Taking the crack of fruit skins as the form of mechanic damnification and using breaking strength to measure the damage, the mechanical parameters for establishing mechanical models and designing relevant devices for grapes and tomatoes were presented.