#[cfg(test)]
mod test;
use crate::{
constitutive::{
ConstitutiveError,
fluid::viscous::Viscous,
solid::{
Solid, TWO_THIRDS, elastic_hyperviscous::ElasticHyperviscous,
hyperviscoelastic::Hyperviscoelastic, viscoelastic::Viscoelastic,
},
},
math::{ContractWith, IDENTITY_00, Quantity, Rank2, TensorRank4},
mechanics::{
Deformation, DeformationGradient, DeformationGradientRate,
SecondPiolaKirchhoffRateTangentStiffness, SecondPiolaKirchhoffStress,
},
units::{Dissipation, EnergyDensity, Stress, Viscosity},
};
#[doc = include_str!("doc.md")]
#[derive(Clone, Debug)]
pub struct SaintVenantKirchhoff {
pub bulk_modulus: Quantity<Stress>,
pub shear_modulus: Quantity<Stress>,
pub bulk_viscosity: Quantity<Viscosity>,
pub shear_viscosity: Quantity<Viscosity>,
}
impl Solid for SaintVenantKirchhoff {
fn bulk_modulus(&self) -> Quantity<Stress> {
self.bulk_modulus
}
fn shear_modulus(&self) -> Quantity<Stress> {
self.shear_modulus
}
}
impl Viscous for SaintVenantKirchhoff {
fn bulk_viscosity(&self) -> Quantity<Viscosity> {
self.bulk_viscosity
}
fn shear_viscosity(&self) -> Quantity<Viscosity> {
self.shear_viscosity
}
}
impl Viscoelastic for SaintVenantKirchhoff {
#[doc = include_str!("second_piola_kirchhoff_stress.md")]
fn second_piola_kirchhoff_stress(
&self,
deformation_gradient: &DeformationGradient,
deformation_gradient_rate: &DeformationGradientRate,
) -> Result<SecondPiolaKirchhoffStress, ConstitutiveError> {
let _jacobian = self.jacobian(deformation_gradient)?;
let (deviatoric_strain, strain_trace) =
((deformation_gradient.right_cauchy_green() - IDENTITY_00) * 0.5)
.deviatoric_and_trace();
let first_term = deformation_gradient_rate.transpose() * deformation_gradient;
let (deviatoric_strain_rate, strain_rate_trace) =
((&first_term + first_term.transpose()) * 0.5).deviatoric_and_trace();
let bulk_modulus = self.bulk_modulus();
let shear_modulus = self.shear_modulus();
let bulk_viscosity = self.bulk_viscosity();
let shear_viscosity = self.shear_viscosity();
Ok(deviatoric_strain * (2.0 * shear_modulus)
+ deviatoric_strain_rate * (2.0 * shear_viscosity)
+ IDENTITY_00 * (bulk_modulus * strain_trace + bulk_viscosity * strain_rate_trace))
}
#[doc = include_str!("second_piola_kirchhoff_rate_tangent_stiffness.md")]
fn second_piola_kirchhoff_rate_tangent_stiffness(
&self,
deformation_gradient: &DeformationGradient,
_: &DeformationGradientRate,
) -> Result<SecondPiolaKirchhoffRateTangentStiffness, ConstitutiveError> {
let _jacobian = self.jacobian(deformation_gradient)?;
let scaled_deformation_gradient_transpose =
deformation_gradient.transpose() * self.shear_viscosity();
Ok(
TensorRank4::dyad_ik_jl(&scaled_deformation_gradient_transpose, &IDENTITY_00)
+ TensorRank4::dyad_il_jk(&IDENTITY_00, &scaled_deformation_gradient_transpose)
+ TensorRank4::dyad_ij_kl(
&(IDENTITY_00 * (self.bulk_viscosity() - TWO_THIRDS * self.shear_viscosity())),
deformation_gradient,
),
)
}
}
impl ElasticHyperviscous for SaintVenantKirchhoff {
#[doc = include_str!("viscous_dissipation.md")]
fn viscous_dissipation(
&self,
deformation_gradient: &DeformationGradient,
deformation_gradient_rate: &DeformationGradientRate,
) -> Result<Quantity<Dissipation>, ConstitutiveError> {
let _jacobian = self.jacobian(deformation_gradient)?;
let first_term = deformation_gradient_rate.transpose() * deformation_gradient;
let strain_rate = (&first_term + first_term.transpose()) * 0.5;
let strain_rate_trace = strain_rate.trace();
Ok(
(&strain_rate * self.shear_viscosity()).contract_with(&strain_rate)
+ (self.bulk_viscosity() - TWO_THIRDS * self.shear_viscosity())
* strain_rate_trace
* strain_rate_trace
* 0.5,
)
}
}
impl Hyperviscoelastic for SaintVenantKirchhoff {
#[doc = include_str!("helmholtz_free_energy_density.md")]
fn helmholtz_free_energy_density(
&self,
deformation_gradient: &DeformationGradient,
) -> Result<Quantity<EnergyDensity>, ConstitutiveError> {
let _jacobian = self.jacobian(deformation_gradient)?;
let strain = (deformation_gradient.right_cauchy_green() - IDENTITY_00) * 0.5;
Ok(self.shear_modulus() * strain.squared_trace()
+ 0.5
* (self.bulk_modulus() - TWO_THIRDS * self.shear_modulus())
* strain.trace().powi(2))
}
}