Degree of multiaxiality (stress multiaxiality) of the amplitude stress tensor

The degree of multiaxiality h describes the stress multiaxiality of the stress tensor T, calculated from the hydrostatic stress σ_H= spur(T)/3 and the equivalent stress according to von-Mises σ_V,GEH

h = σ_H / σ_V,GEH

h has the following characteristic values:
h = 0 → stress state is multi-axial and dominated by shear stress
h = ±1/3 →stress state is uniaxial and normal stress-dominated
h = ±2/3 →stress state is biaxial and normal stress-dominated
h → ±∞ → stress state is triaxial and normal stress-dominated