The Lagrangian Seth-Hill elastic solid constitutive model.[^1]<sup>,</sup>[^2]
**Parameters**
- The bulk modulus $`\kappa`$.
- The shear modulus $`\mu`$.
- The exponent $`m`$.
**External variables**
- The deformation gradient $`\mathbf{F}`$.
**Internal variables**
- None.
**Notes**
- The Seth-Hill strain measure is given by $`\mathbf{E}^{(m)} = \tfrac{1}{m}(\mathbf{U}^m - \mathbf{1})`$.
- The model reduces to the elastic [Hencky model](super::Hencky) when $`m=0`$.
- The model reduces to the hyperelastic [Saint Venant-Kirchhoff model](super::super::hyperelastic::SaintVenantKirchhoff) when $`m=2`$.
- The model reduces to the [Lagrangian Almansi-Hamel model](super::AlmansiHamelLagrangian) when $`m=-2`$.
- This is the Lagrangian counterpart of the [Eulerian Seth-Hill model](super::SethHillEulerian).