diff --git a/doc/src/bond_bpm_rotational.rst b/doc/src/bond_bpm_rotational.rst index ba93d679ba..0baf7e35b1 100644 --- a/doc/src/bond_bpm_rotational.rst +++ b/doc/src/bond_bpm_rotational.rst @@ -30,6 +30,9 @@ Syntax *smooth* value = *yes* or *no* smooths bond forces near the breaking point + *normalize* value = *yes* or *no* + normalizes normal and shear forces by the reference length + *break/no* indicates that bonds should not break during a run @@ -136,6 +139,9 @@ or :doc:`read_restart ` commands: * :math:`\gamma_r` (force*distance/velocity units) * :math:`\gamma_t` (force*distance/velocity units) +However, the *normalize* option will normalize the radial and shear forces +by :math:`r_0` such that :math:`k_r` and :math:`k_s` are unit less. + By default, pair forces are not calculated between bonded particles. Pair forces can alternatively be overlaid on top of bond forces using the *overlay/pair* keyword. These settings require specific diff --git a/doc/src/bond_bpm_spring.rst b/doc/src/bond_bpm_spring.rst index 5762dbe208..6da0d25a4a 100644 --- a/doc/src/bond_bpm_spring.rst +++ b/doc/src/bond_bpm_spring.rst @@ -30,6 +30,9 @@ Syntax *smooth* value = *yes* or *no* smooths bond forces near the breaking point + *normalize* value = *yes* or *no* + normalizes bond forces by their reference length + *break/no* indicates that bonds should not break during a run @@ -66,7 +69,7 @@ particles based on a model described by Clemmer and Robbins F = k (r - r_0) w -where :math:`k_r` is a stiffness, :math:`r` is the current distance +where :math:`k` is a stiffness, :math:`r` is the current distance and :math:`r_0` is the initial distance between the two particles, and :math:`w` is an optional smoothing factor discussed below. Bonds will break at a strain of :math:`\epsilon_c`. This is done by setting by @@ -102,6 +105,9 @@ the data file or restart files read by the :doc:`read_data * :math:`\epsilon_c` (unit less) * :math:`\gamma` (force/velocity units) +However, the *normalize* option will normalize the elastic bond force by +:math:`r_0` such that :math:`k` is unit less. + By default, pair forces are not calculated between bonded particles. Pair forces can alternatively be overlaid on top of bond forces using the *overlay/pair* keyword. These settings require specific diff --git a/doc/src/compute_bond_local.rst b/doc/src/compute_bond_local.rst index f3fb752ebe..10e86bbe44 100644 --- a/doc/src/compute_bond_local.rst +++ b/doc/src/compute_bond_local.rst @@ -76,7 +76,10 @@ The value *force* is the magnitude of the force acting between the pair of atoms in the bond. The values *fx*, *fy*, and *fz* are the xyz components of -*force* between the pair of atoms in the bond. +*force* between the pair of atoms in the bond. For bond styles that apply +non-central forces, such as :doc:`bond_style bpm/rotational +`, these values only include the :math:`(x,y,z)` +components of the normal force component. The remaining properties are all computed for motion of the two atoms relative to the center of mass (COM) velocity of the 2 atoms in the diff --git a/doc/src/compute_pair_local.rst b/doc/src/compute_pair_local.rst index dace280dee..31209f63f4 100644 --- a/doc/src/compute_pair_local.rst +++ b/doc/src/compute_pair_local.rst @@ -66,7 +66,9 @@ The value *eng* is the interaction energy for the pair of atoms. The value *force* is the force acting between the pair of atoms, which is positive for a repulsive force and negative for an attractive force. The values *fx*, *fy*, and *fz* are the :math:`(x,y,z)` components of -*force* on atom I. +*force* on atom I. For pair styles that apply non-central forces, +such as :doc:`granular pair styles `, these values only include +the :math:`(x,y,z)` components of the normal force component. A pair style may define additional pairwise quantities which can be accessed as *p1* to *pN*, where :math:`N` is defined by the pair style.