Finite strains
This module contains some methods to calculate several finite strains. The following formulae are from the Gibbs2
paper Table 3.
Eulerian strain:
\[f = \frac{ 1 }{ 2 } \bigg( \Big \frac{ V_0 }{ V } \Big^{\frac{ 2 }{ 3 }} - 1 \bigg)\]
Lagrangian strain:
\[f = \frac{ 1 }{ 2 } \bigg( \Big( \frac{ V }{ V_0 } \Big^{\frac{ 2 }{ 3 }} - 1 \bigg)\]
Natural (Hencky) strain:
\[f = \frac{ 1 }{ 3 } \ln \Big \frac{ V }{ V_0 } \Big\]
Infinitesimal strain:
\[f = 1 - \Big \frac{ V_0 }{ V } \Big^{\frac{ 1 }{ 3 }}\]
EquationsOfStateOfSolids.FiniteStrains.VolumeTo
— TypeEulerianStrainFromVolume(v0)
LagrangianStrainFromVolume(v0)
NaturalStrainFromVolume(v0)
InfinitesimalStrainFromVolume(v0)
Calculate the finite strain of v
based on the reference volume v0
.
Examples
julia> f = EulerianStrainFromVolume(10);
julia> f(9)
0.036382991447572066
julia> f = EulerianStrainFromVolume(100u"nm^3");
julia> f(90u"nm^3")
0.036382991447572066
julia> g = inv(f);
julia> g ∘ f == f ∘ g == identity
true
EquationsOfStateOfSolids.FiniteStrains.VolumeFrom
— TypeVolumeFromEulerianStrain(v0)
VolumeFromLagrangianStrain(v0)
VolumeFromNaturalStrain(v0)
VolumeFromInfinitesimalStrain(v0)
Calculate the original volume v
from the finite strain f
based on the reference volume v0
.
Examples
julia> g = VolumeFromEulerianStrain(10);
julia> g(0.036382991447572066)
9.000000000000002
julia> g = VolumeFromEulerianStrain(100u"nm^3");
julia> g(0.036382991447572066)
90.00000000000001 nm³
julia> f = inv(g);
julia> f ∘ g == g ∘ f == identity
true