“…We can formulate Hooke’s law to define the stress tensor as a linear combination of the volumetric and deviatoric strain tensors: where K is the bulk modulus and G is the shear modulus. From Equation ( 1 ), it is possible then to recognize the two contributions to the stress, namely the hydrostatic: and shear or deviatoric part: This formulation can be generalized by using mechanical micromorphic [ 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ], micropolar [ 57 , 58 , 59 , 60 ], higher-order [ 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ], or peridynamic [ 71 , 72 , 73 , 74 ] models. As an opening move, the stiffnesses can be evaluated starting with the knowledge of the engineering parameters, Young’s modulus Y , and Poisson’s ratio as follows: since they are more str...…”