From 461dd67bb4d882328db76bf3cae16c4335bcc712 Mon Sep 17 00:00:00 2001 From: jtclemm Date: Tue, 26 Nov 2024 10:37:13 -0700 Subject: [PATCH] Clarifying Tsuji damping doc, removing overloaded variable --- doc/src/pair_granular.rst | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/doc/src/pair_granular.rst b/doc/src/pair_granular.rst index b0d7cf83be..b4341961cc 100644 --- a/doc/src/pair_granular.rst +++ b/doc/src/pair_granular.rst @@ -235,12 +235,14 @@ given by: .. math:: - \eta_n = \alpha (m_{eff}k_n)^{1/2} + \eta_n = \alpha (m_{eff}k_{nd})^{1/2} -For normal contact models based on material parameters, :math:`k_n = 4/3Ea`. This -damping model is not compatible with cohesive normal models such as *JKR* or *DMT*. -The parameter :math:`\alpha` is related to the restitution coefficient *e* -according to: +where :math:`k_{nd}` is an effective harmonic stiffness equal to the ratio of +the normal force to the overlap. For example, :math:`k_{nd} = 4/3Ea` for a +Hertz contact model based on material parameters with :math:`a` being +the contact radius of :math:`\sqrt{\delta R}`. This damping model is not +compatible with cohesive normal models such as *JKR* or *DMT*. The parameter +:math:`\alpha` is related to the restitution coefficient *e* according to: .. math::