Mechanical characterization of kernel and shell of hazelnuts: Proposal of an experimental procedure

• We defined many experimental procedures to test hazelnuts shell and kernel materials.
• We defined a data processing procedure and material parameters to describe material properties.
• We defined specimens shape to obtain material data.
• We validated the procedures with experimental testing on conform and nonconform hazelnut shell and kernels.

In order to improve the performance of selecting machines for non-conform and damaged hazelnuts and to enhance the numerical modelling of anisotropic behaviour of hazelnuts, the mechanical properties of shells and kernels are useful experimental data. A procedure to experimentally obtain physical and mechanical properties of hazelnuts is described and the optimized specimen shapes to obtain stress to failure and elastic modulus values for kernel and shell are also defined. The procedure is applied to a commercial variety of Italian hazelnuts and the mechanical properties are experimentally obtained both for kernel and shell on specimens made from conform and damaged hazelnuts.