elastic sphere
2.Applying the theory of sphere contact, lichee elastic modulus measuring equation with small deformation was deduced. The lichee acting force at small deformation was dynamically measured on a self-designed measuring platform for agricultural material. The elastic modulus of lichee which ranges in 0.3x104~1.0x104Pa was achieved.
3.Sphere indentation stress strain relation and contact damage for pure brittle and quasi bri ttle materials were investigated using steel spheres with different sizes as the indenter. Elastic modulus and the critical stress to cause damage were determined on the base of linear elastic relationship between the load and the contact area.
4.Supposed rice as sphere, the image recognizition method was used to pick up the size of three axises, utilizing formula of curvature radius to deduce the curvature radius of rice on the contacting when it was compressed by flat. Hertz contacting theory was used to analyze rice extrusion equation and stress distribution on contacting side, and deduce rice compression elastic modulus.
