"""
DEM API
=======
Module for creating a DEM DYNA input deck.
"""
import logging
from .dynabase import * # noqa : F403
[docs]
class DynaDEM(DynaBase):
"""Contains methods for creating a keyword related to a discrete element method."""
def __init__(self):
DynaBase.__init__(self)
[docs]
def set_des(self, ndamp=0.0, tdamp=0.0, frics=0.0, fricr=0.0, normk=0.01, sheark=0.2857):
"""Set global control parameters for discrete element spheres.
Parameters
----------
ndamp : float, optional
Normal damping coefficient. The default is ``0.0``.
tdamp : float, optional
Tangential damping coefficient. The default is ``0.0``.
frics : float, optional
Static coefficient of friction. The default is ``0.0``.
- EQ.0: 3 DOF
- NE.0: 6 DOF
fricr : float, optional
Rolling friction coefficient. The default is ``0.0``.
normk : float, optional
Scale factor of the normal spring constant. The default is ``0.01``.
sheark : float, optional
Ratio between the sheark/normk. The default is ``0.2857``.
Returns
-------
bool
``True`` when successful, ``False`` when failed.
"""
ret = self.stub.CreateControlDiscreteElement(
ControlDiscreteElementRequest(
ndamp=ndamp,
tdamp=tdamp,
frics=frics,
fricr=fricr,
normk=normk,
sheark=sheark,
)
)
logging.info("Control DES Created...")
return ret
[docs]
def create_define_de_mesh_surface(self, sid, type, despid, desxid, nquad=1, nsid=0, rsf=1.0):
"""Create discrete element sphere (DES) elements on the surface of shell elements.
Parameters
----------
sid : int
Part or part set ID for the region of the mesh to place DES elements on.
type : int
SID type:
- type=0: Part set ID
- type=1: Part ID
despid : int
Part ID for the generated DES elements.
desxid : int
Section ID for the generated DES elements.
nquad : int, optional
Number of equally spaced DES elements created on a shell element in each
local shell direction. The default is ``1``.
nsid : int, optional
If defined, this card creates a node set with ID NSID for the nodes generated
by this card. The default is ``0``.
rsf : float, optional
Scale factor for determining the DES radius. The default is ``1.0``.
Returns
-------
bool
``True`` when successful, ``False`` when failed.
"""
ret = self.stub.CreateDefineDEMeshSurface(
DefineDEMeshSurfaceRequest(
sid=sid,
type=type,
despid=despid,
desxid=desxid,
nquad=nquad,
nsid=nsid,
rsf=rsf,
)
)
logging.info("Define discrete element mesh surface Created...")
return ret
[docs]
def save_file(self):
"""Save keyword files.
Returns
-------
bool
``True`` when successful, ``False`` when failed.
"""
DynaBase.save_file(self)
[docs]
class DEMAnalysis(BaseObj):
"""Activates DEM analysis and defines associated control parameters."""
def __init__(self):
[docs]
self.defined_des = False
[docs]
self.stub = DynaBase.get_stub()
[docs]
self.type = "analysis_dem"
[docs]
def set_des(
self,
normal_damping_coeff=0.0,
tangential_damping_coeff=0.0,
static_friction_coeff=0.0,
rolling_friction_coeff=0.0,
normal_spring_constant_sf=0.01,
ratio=0.2857,
):
"""Set global control parameters for discrete element spheres.
Parameters
----------
normal_damping_coeff : float, optional
Normal damping coefficient. The default value is ``0.0``.
tangential_damping_coeff : float, optional
Tangential damping coefficient. The default value is ``0.0``.
static_friction_coeff : float, optional
Static coefficient of friction. The default is ``0.0``.
rolling_friction_coeff : float, optional
Rolling coefficient of friction. The default is ``0.0``.
normal_spring_constant_sf : float, optional
Normal spring constant. The default is ``0.01``.
ratio : float, optional
Ratio. The default is ``0.2857``.
"""
self.defined_des = True
self.ndamp = normal_damping_coeff
self.tdamp = tangential_damping_coeff
self.frics = static_friction_coeff
self.fricr = rolling_friction_coeff
self.normk = normal_spring_constant_sf
self.sheark = ratio
[docs]
def create(self):
"""Create a DEM analysis."""
if self.defined_des:
self.stub.CreateControlDiscreteElement(
ControlDiscreteElementRequest(
ndamp=self.ndamp,
tdamp=self.tdamp,
frics=self.frics,
fricr=self.fricr,
normk=self.normk,
sheark=self.sheark,
)
)
