diff --git a/doc/src/pair_granular.rst b/doc/src/pair_granular.rst index d5f522462d..294bec9b8c 100644 --- a/doc/src/pair_granular.rst +++ b/doc/src/pair_granular.rst @@ -432,7 +432,7 @@ option by an additional factor of *a*\ , the radius of the contact region. The t Here, *a* is the radius of the contact region, given by :math:`a =\sqrt{R\delta}` for all normal contact models, except for *jkr*\ , where it is given implicitly by :math:`\delta = a^2/R - 2\sqrt{\pi \gamma a/E}`, see -discussion above. To match the Mindlin solution, one should set :math:`k_t = 8G`, where :math:`G` is the shear modulus, related to Young's modulus +discussion above. To match the Mindlin solution, one should set :math:`k_t = 4G/(2-\nu)`, where :math:`G` is the shear modulus, related to Young's modulus :math:`E` by :math:`G = E/(2(1+\nu))`, where :math:`\nu` is Poisson's ratio. This can also be achieved by specifying *NULL* for :math:`k_t`, in which case a normal contact model that specifies material parameters :math:`E` and