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

1#[cfg(test)]
2mod test;
3
4use crate::{
5    constitutive::{
6        Constitutive, ConstitutiveError, Parameters,
7        solid::{FIVE_THIRDS, Solid, TWO_THIRDS, elastic::Elastic, hyperelastic::Hyperelastic},
8    },
9    math::{IDENTITY, Rank2},
10    mechanics::{CauchyStress, CauchyTangentStiffness, Deformation, DeformationGradient, Scalar},
11};
12
13const SEVEN_THIRDS: Scalar = 7.0 / 3.0;
14
15#[doc = include_str!("doc.md")]
16#[derive(Debug)]
17pub struct Yeoh<P> {
18    parameters: P,
19}
20
21impl<P> Yeoh<P>
22where
23    P: Parameters,
24{
25    /// Returns an array of the moduli.
26    pub fn moduli(&self) -> &[Scalar] {
27        // panic!()
28        self.parameters.get_slice(1..)
29    }
30    /// Returns an array of the extra moduli.
31    pub fn extra_moduli(&self) -> &[Scalar] {
32        // panic!()
33        self.parameters.get_slice(2..)
34    }
35}
36
37impl<P> Constitutive<P> for Yeoh<P>
38where
39    P: Parameters,
40{
41    fn new(parameters: P) -> Self {
42        Self { parameters }
43    }
44}
45
46impl<P> Solid for Yeoh<P>
47where
48    P: Parameters,
49{
50    fn bulk_modulus(&self) -> &Scalar {
51        self.parameters.get(0)
52    }
53    fn shear_modulus(&self) -> &Scalar {
54        self.parameters.get(1)
55    }
56}
57
58impl<P> Elastic for Yeoh<P>
59where
60    P: Parameters,
61{
62    #[doc = include_str!("cauchy_stress.md")]
63    fn cauchy_stress(
64        &self,
65        deformation_gradient: &DeformationGradient,
66    ) -> Result<CauchyStress, ConstitutiveError> {
67        let jacobian = self.jacobian(deformation_gradient)?;
68        let (deviatoric_left_cauchy_green_deformation, left_cauchy_green_deformation_trace) =
69            deformation_gradient
70                .left_cauchy_green()
71                .deviatoric_and_trace();
72        let scalar_term = left_cauchy_green_deformation_trace / jacobian.powf(TWO_THIRDS) - 3.0;
73        Ok(deviatoric_left_cauchy_green_deformation
74            * self
75                .moduli()
76                .iter()
77                .enumerate()
78                .map(|(n, modulus)| ((n as Scalar) + 1.0) * modulus * scalar_term.powi(n as i32))
79                .sum::<Scalar>()
80            / jacobian.powf(FIVE_THIRDS)
81            + IDENTITY * self.bulk_modulus() * 0.5 * (jacobian - 1.0 / jacobian))
82    }
83    #[doc = include_str!("cauchy_tangent_stiffness.md")]
84    fn cauchy_tangent_stiffness(
85        &self,
86        deformation_gradient: &DeformationGradient,
87    ) -> Result<CauchyTangentStiffness, ConstitutiveError> {
88        let jacobian = self.jacobian(deformation_gradient)?;
89        let inverse_transpose_deformation_gradient = deformation_gradient.inverse_transpose();
90        let left_cauchy_green_deformation = deformation_gradient.left_cauchy_green();
91        let scalar_term = left_cauchy_green_deformation.trace() / jacobian.powf(TWO_THIRDS) - 3.0;
92        let scaled_modulus = self
93            .moduli()
94            .iter()
95            .enumerate()
96            .map(|(n, modulus)| ((n as Scalar) + 1.0) * modulus * scalar_term.powi(n as i32))
97            .sum::<Scalar>()
98            / jacobian.powf(FIVE_THIRDS);
99        let deviatoric_left_cauchy_green_deformation = left_cauchy_green_deformation.deviatoric();
100        let last_term = CauchyTangentStiffness::dyad_ij_kl(
101            &deviatoric_left_cauchy_green_deformation,
102            &((left_cauchy_green_deformation.deviatoric()
103                * &inverse_transpose_deformation_gradient)
104                * (2.0
105                    * self
106                        .extra_moduli()
107                        .iter()
108                        .enumerate()
109                        .map(|(n, modulus)| {
110                            ((n as Scalar) + 2.0)
111                                * ((n as Scalar) + 1.0)
112                                * modulus
113                                * scalar_term.powi(n as i32)
114                        })
115                        .sum::<Scalar>()
116                    / jacobian.powf(SEVEN_THIRDS))),
117        );
118        Ok(
119            (CauchyTangentStiffness::dyad_ik_jl(&IDENTITY, deformation_gradient)
120                + CauchyTangentStiffness::dyad_il_jk(deformation_gradient, &IDENTITY)
121                - CauchyTangentStiffness::dyad_ij_kl(&IDENTITY, deformation_gradient)
122                    * (TWO_THIRDS))
123                * scaled_modulus
124                + CauchyTangentStiffness::dyad_ij_kl(
125                    &(IDENTITY * (0.5 * self.bulk_modulus() * (jacobian + 1.0 / jacobian))
126                        - deviatoric_left_cauchy_green_deformation
127                            * (scaled_modulus * FIVE_THIRDS)),
128                    &inverse_transpose_deformation_gradient,
129                )
130                + last_term,
131        )
132    }
133}
134
135impl<P> Hyperelastic for Yeoh<P>
136where
137    P: Parameters,
138{
139    #[doc = include_str!("helmholtz_free_energy_density.md")]
140    fn helmholtz_free_energy_density(
141        &self,
142        deformation_gradient: &DeformationGradient,
143    ) -> Result<Scalar, ConstitutiveError> {
144        let jacobian = self.jacobian(deformation_gradient)?;
145        let scalar_term =
146            deformation_gradient.left_cauchy_green().trace() / jacobian.powf(TWO_THIRDS) - 3.0;
147        Ok(0.5
148            * (self
149                .moduli()
150                .iter()
151                .enumerate()
152                .map(|(n, modulus)| modulus * scalar_term.powi((n + 1) as i32))
153                .sum::<Scalar>()
154                + self.bulk_modulus() * (0.5 * (jacobian.powi(2) - 1.0) - jacobian.ln())))
155    }
156}
conspire/constitutive/solid/hyperelastic/yeoh/mod.rs

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