conspire/constitutive/solid/hyperelastic/hencky/
mod.rs

1#[cfg(test)]
2mod test;
3
4use crate::{
5    constitutive::{
6        Constitutive, ConstitutiveError, Parameters,
7        solid::{Solid, TWO_THIRDS, elastic::Elastic, hyperelastic::Hyperelastic},
8    },
9    math::{ContractThirdFourthIndicesWithFirstSecondIndicesOf, IDENTITY, Rank2},
10    mechanics::{CauchyStress, CauchyTangentStiffness, Deformation, DeformationGradient, Scalar},
11};
12
13#[doc = include_str!("doc.md")]
14#[derive(Debug)]
15pub struct Hencky<P> {
16    parameters: P,
17}
18
19impl<P> Constitutive<P> for Hencky<P>
20where
21    P: Parameters,
22{
23    fn new(parameters: P) -> Self {
24        Self { parameters }
25    }
26}
27
28impl<P> Solid for Hencky<P>
29where
30    P: Parameters,
31{
32    fn bulk_modulus(&self) -> &Scalar {
33        self.parameters.get(0)
34    }
35    fn shear_modulus(&self) -> &Scalar {
36        self.parameters.get(1)
37    }
38}
39
40impl<P> Elastic for Hencky<P>
41where
42    P: Parameters,
43{
44    #[doc = include_str!("cauchy_stress.md")]
45    fn cauchy_stress(
46        &self,
47        deformation_gradient: &DeformationGradient,
48    ) -> Result<CauchyStress, ConstitutiveError> {
49        let jacobian = self.jacobian(deformation_gradient)?;
50        let (deviatoric_strain, strain_trace) =
51            (deformation_gradient.left_cauchy_green().logm() * 0.5).deviatoric_and_trace();
52        Ok(deviatoric_strain * (2.0 * self.shear_modulus() / jacobian)
53            + IDENTITY * (self.bulk_modulus() * strain_trace / jacobian))
54    }
55    #[doc = include_str!("cauchy_tangent_stiffness.md")]
56    fn cauchy_tangent_stiffness(
57        &self,
58        deformation_gradient: &DeformationGradient,
59    ) -> Result<CauchyTangentStiffness, ConstitutiveError> {
60        let jacobian = self.jacobian(deformation_gradient)?;
61        let left_cauchy_green = deformation_gradient.left_cauchy_green();
62        let (deviatoric_strain, strain_trace) =
63            (left_cauchy_green.logm() * 0.5).deviatoric_and_trace();
64        let scaled_deformation_gradient = deformation_gradient * self.shear_modulus() / jacobian;
65        Ok((left_cauchy_green
66            .dlogm()
67            .contract_third_fourth_indices_with_first_second_indices_of(
68                &(CauchyTangentStiffness::dyad_il_jk(&scaled_deformation_gradient, &IDENTITY)
69                    + CauchyTangentStiffness::dyad_ik_jl(&IDENTITY, &scaled_deformation_gradient)),
70            ))
71            + (CauchyTangentStiffness::dyad_ij_kl(
72                &(IDENTITY
73                    * ((self.bulk_modulus() - TWO_THIRDS * self.shear_modulus()) / jacobian)
74                    - deviatoric_strain * (2.0 * self.shear_modulus() / jacobian)
75                    - IDENTITY * (self.bulk_modulus() * strain_trace / jacobian)),
76                &deformation_gradient.inverse_transpose(),
77            )))
78    }
79}
80
81impl<P> Hyperelastic for Hencky<P>
82where
83    P: Parameters,
84{
85    #[doc = include_str!("helmholtz_free_energy_density.md")]
86    fn helmholtz_free_energy_density(
87        &self,
88        deformation_gradient: &DeformationGradient,
89    ) -> Result<Scalar, ConstitutiveError> {
90        let _jacobian = self.jacobian(deformation_gradient)?;
91        let strain = deformation_gradient.left_cauchy_green().logm() * 0.5;
92        Ok(self.shear_modulus() * strain.squared_trace()
93            + 0.5
94                * (self.bulk_modulus() - TWO_THIRDS * self.shear_modulus())
95                * strain.trace().powi(2))
96    }
97}
conspire/constitutive/solid/hyperelastic/hencky/mod.rs

conspire/constitutive/solid/hyperelastic/hencky/
mod.rs
