diff --git a/src/felupe/constitution/tensortrax/models/hyperelastic/__init__.py b/src/felupe/constitution/tensortrax/models/hyperelastic/__init__.py
index 6b6bbf56..9f880054 100644
--- a/src/felupe/constitution/tensortrax/models/hyperelastic/__init__.py
+++ b/src/felupe/constitution/tensortrax/models/hyperelastic/__init__.py
@@ -14,6 +14,7 @@
from ._arruda_boyce import arruda_boyce
from ._extended_tube import extended_tube
from ._finite_strain_viscoelastic import finite_strain_viscoelastic
+from ._foam import foam
from ._lopez_pamies import lopez_pamies
from ._miehe_goektepe_lulei import miehe_goektepe_lulei
from ._mooney_rivlin import mooney_rivlin
@@ -32,6 +33,7 @@
"arruda_boyce",
"extended_tube",
"finite_strain_viscoelastic",
+ "foam",
"lopez_pamies",
"miehe_goektepe_lulei",
"mooney_rivlin",
@@ -50,6 +52,7 @@
anssari_benam_bucchi.kwargs = dict(mu=0, N=100)
arruda_boyce.kwargs = dict(C1=0, limit=100)
extended_tube.kwargs = dict(Gc=0, Ge=0, beta=1, delta=0)
+foam.kwargs = dict(mu=[0, 0], alpha=[2, -2], beta=[1, 1])
lopez_pamies.kwargs = dict(mu=[0, 0], alpha=[1, 4])
miehe_goektepe_lulei.kwargs = dict(mu=0, N=100, U=0, p=2, q=2)
mooney_rivlin.kwargs = dict(C10=0, C01=0)
diff --git a/src/felupe/constitution/tensortrax/models/hyperelastic/_foam.py b/src/felupe/constitution/tensortrax/models/hyperelastic/_foam.py
new file mode 100644
index 00000000..fe760103
--- /dev/null
+++ b/src/felupe/constitution/tensortrax/models/hyperelastic/_foam.py
@@ -0,0 +1,122 @@
+# -*- coding: utf-8 -*-
+"""
+This file is part of FElupe.
+
+FElupe is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+FElupe is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with FElupe. If not, see .
+"""
+
+from tensortrax.math import sum as tsum
+from tensortrax.math.linalg import det, eigvalsh
+
+
+def foam(C, mu, alpha, beta):
+ r"""Strain energy function of the isotropic hyperelastic
+ `Foam `_ material formulation [1]_.
+
+ Parameters
+ ----------
+ C : tensortrax.Tensor
+ Right Cauchy-Green deformation tensor.
+ mu : list of float
+ List of moduli.
+ alpha : list of float
+ List of stretch exponents.
+ beta : list of float
+ List of coefficients for the degree of compressibility.
+
+ Notes
+ -----
+ The strain energy function is given in Eq. :eq:`psi-foam`
+
+ .. math::
+ :label: psi-ogden
+
+ \psi = \sum_i \frac{2 \mu_i}{\alpha^2_i} \left[
+ \hat{\lambda}_1^{\alpha_i} +
+ \hat{\lambda}_2^{\alpha_i} +
+ \hat{\lambda}_3^{\alpha_i} - 3
+ + \frac{1}{\beta_i} \left( J^{-\alpha \beta} - 1 \right)
+ \right]
+
+ The sum of the moduli :math:`\mu_i` is equal to the initial shear modulus
+ :math:`\mu`, see Eq. :eq:`shear-modulus-foam`.
+
+ .. math::
+ :label: shear-modulus-ogden
+
+ \mu = \sum_i \mu_i
+
+ The initial bulk modulus is given in Eq. :eq:`bulk-modulus-foam`.
+
+ .. math::
+ :label: bulk-modulus-ogden
+
+ K = \sum_i 2 \mu_i \left( \frac{1}{3} + \beta_i \right)
+
+ Examples
+ --------
+ First, import the automatic differentiation backend
+
+ .. pyvista-plot::
+ :context:
+
+ >>> import felupe.constitution.tensortrax as mat
+
+ and create the hyperelastic material.
+
+ .. pyvista-plot::
+ :context:
+
+ >>> import felupe as fem
+ >>>
+ >>> umat = mat.Hyperelastic(
+ ... mat.models.hyperelastic.foam,
+ ... mu=[4.5 * (1.85 / 2), -4.5 * (-9.2 / 2)],
+ ... alpha=[1.85, -9.2],
+ ... beta=[0.92, 0.92],
+ ... )
+ >>> ax = umat.plot(
+ ... ux=fem.math.linsteps([1, 2], 20),
+ ... ps=fem.math.linsteps([1, 2], 20),
+ ... bx=fem.math.linsteps([1, 1.5], 10),
+ ... )
+
+ .. pyvista-plot::
+ :include-source: False
+ :context:
+ :force_static:
+
+ >>> import pyvista as pv
+ >>>
+ >>> fig = ax.get_figure()
+ >>> chart = pv.ChartMPL(fig)
+ >>> chart.show()
+
+ References
+ ----------
+ .. [1] B. Storåkers, "On material representation and constitutive branching in
+ finite compressible elasticity", Journal of the Mechanics and Physics of Solids,
+ vol. 34, no. 2. Elsevier BV, pp. 125–145, Jan. 1986. doi:
+ 10.1016/0022-5096(86)90033-5.
+ """
+
+ I3 = det(C)
+ λ2 = I3 ** (-1 / 3) * eigvalsh(C)
+
+ return tsum(
+ [
+ 2 * μ / α**2 * ((tsum(λ2 ** (α / 2)) - 3) + (I3 ** (-α * β / 2) - 1) / β)
+ for μ, α, β in zip(mu, alpha, beta)
+ ]
+ )