Source Code for Module mbdyn.elements

  1  #!/usr/bin/env python 
  2  # -*- coding: utf-8 -*- 
  3  # 
  4  # This file is part of MBDyn sim suite. 
  5  # Copyright (C) 2007 André ESPAZE, as part of a Master thesis supervised by 
  6  # Martin O.L.Hansen (DTU) and Nicolas Chauvat (Logilab) 
  7   
  8  # MBDyn sim suite is free software; you can redistribute it and/or modify 
  9  # it under the terms of the GNU General Public License as published by 
 10  # the Free Software Foundation; either version 2 of the License, or 
 11  # (at your option) any later version. 
 12  # 
 13  # This program is distributed in the hope that it will be useful, 
 14  # but WITHOUT ANY WARRANTY; without even the implied warranty of 
 15  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 16  # GNU General Public License for more details. 
 17  # 
 18  # You should have received a copy of the GNU General Public License 
 19  # along with this program; if not, write to the Free Software 
 20  # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 
 21  # 
 22  """The module gathering all the elements. 
 23  All the MBDyn elements that have an interface are contained 
 24  in the ELEM_CLASS dictionary of that file. 
 25   
 26  The ELEM_CLASS is divided into all the MBDyn groups, each group 
 27  is another dictionary with all its classes. 
 28   
 29  For example:  
 30  ForceClass = ELEM_CLASS["FORCE"]["BindingsForce"] 
 31  will return the BindingsForce class. 
 32  """ 
 33  from mbdyn.common import MANAGER 
 34  from mbdyn.general import NULL, EYE 
 35  from mbdyn.references import NONE_REF 
 36   
 37  from mbdyn.elements_base import ELEM_CLASS, ElementWithoutNode, ElementWithNode 
 38   
 39  from mbdyn.elts.aerodynamic import AERODYNAMIC_CLASS 
 40  from mbdyn.elts.beam import BEAM_CLASS 
 41  from mbdyn.elts.force import FORCE_CLASS 
 42  from mbdyn.elts.joint import JOINT_CLASS 
 43   
 44   
 45  ELEM_CLASS["AERODYNAMIC"] = AERODYNAMIC_CLASS 
 46  ELEM_CLASS["BEAM"] = BEAM_CLASS 
 47  ELEM_CLASS["FORCE"] = FORCE_CLASS 
 48  ELEM_CLASS["JOINT"] = JOINT_CLASS 
 49   
 50   
 51 -class AirProperties(ElementWithoutNode): 
 52      """The MBDyn air properties. 
 53      This  object is not attached to any node. Until know, only  
 54      constant driver can be used, set by the 'set_value' method. 
 55      """ 
 56   
 57 -    def __init__(self, name="air properties"): 
 58          ElementWithoutNode.__init__(self, name) 
 59          self.mbdyn_type = "air properties" 
 60          self.class_key = "AirProperties" 
 61          self.group_key = "AIRPROPERTIES" 
 62          self.control_data_without_values = [("air properties")] 
 63          self.arg_names = ["density", "sound_celerity", 
 64                            "velocity", "value"] 
 65   
 66 -    def set_density(self, value, com=None): 
 67          """Set the density of the air in 'kg/m3'""" 
 68          MANAGER.add_argument(self, "density", value, com) 
 69   
 70 -    def set_sound_celerity(self, value, com=None): 
 71          """Set the sound celerity in 'm/s'""" 
 72          MANAGER.add_argument(self, "sound_celerity", value, com) 
 73   
 74 -    def set_velocity(self, *args, **kargs): 
 75          """Set the velocity vector in 'm/s'""" 
 76          MANAGER.add_vector(self, "velocity", args, kargs) 
 77   
 78   
 79  ELEM_CLASS["AIRPROPERTIES"]["AirProperties"] = AirProperties 
 80   
 81   
 82 -class Gravity(ElementWithoutNode): 
 83      """The MBDyn gravity object.  
 84      This element is not attached to any node. 
 85   
 86      An example of use:: 
 87   
 88          grav = Gravity() 
 89          grav.set_direction(0., 0., -1.) 
 90          grav.set_value(9.81) 
 91       
 92      C{grav} can then be added to the  
 93      L{Simulation<mbdyn.main.Simulation>} object by C{add_element}. 
 94      """ 
 95   
 96 -    def __init__(self, name="gravity"): 
 97          ElementWithoutNode.__init__(self, name) 
 98          self.mbdyn_type = "gravity" 
 99          self.class_key = "Gravity" 
100          self.group_key = "GRAVITY" 
101          self.control_data_without_values = [("gravity")] 
102          self.arg_names = ["direction", "value"] 
103   
104 -    def set_direction(self, *args, **kargs): 
105          """Set the gravity direction""" 
106          MANAGER.add_vector(self, "direction", args, kargs) 
107   
108   
109  ELEM_CLASS["GRAVITY"]["Gravity"] = Gravity 
110       
111   
112 -class Body(ElementWithNode): 
113      """A MBDyn body with a mass, a center of mass and  
114      and an inertia matrix. A body needs to be attached 
115      to a node, so the body properties are provided 
116      according to the node reference frame. There is usually no need to 
117      use the C{set_relative_from} method, but it may be used anyway to 
118      set an different center of mass by using a reference frame. 
119   
120      Example of use:: 
121       
122          body = M.body() 
123          body.attach_to(node) 
124          body.set_mass(1.) 
125          body.set_center_of_mass(0.5, 0., 0.) 
126       
127      By default a body has a mass of M{1. kg}, no offset 
128      and an eye inertia matrix. 
129      """ 
130   
131 -    def __init__(self, name="body"): 
132          ElementWithNode.__init__(self, name) 
133          self.mbdyn_type = "body" 
134          self.class_key = "Body" 
135          self.group_key = "BODY" 
136          self.arg_names += ["node", 
137                             "mass", 
138                             "center_of_mass", 
139                             "inertia_matrix"]  
140          self.control_data_with_values = [("rigid bodies", 
141                                            "+1  # %s" % name)] 
142          self.set_default() 
143   
144 -    def set_default(self): 
145          """Set the default definition of a body, those values will stay 
146          unless specify by the user""" 
147          self.set_mass(1.) 
148          self.set_center_of_mass(NULL, ref=NONE_REF) 
149          self.set_inertia_matrix(EYE, ref=NONE_REF) 
150   
151 -    def set_relative_from(self, ref): 
152          """The properties will be set relative to the provided 
153          reference frame""" 
154          # 'set_default' must not be called in that case 
155          # because the properties are assumed to be input 
156          # relative to the node orientation matrix. 
157          self.ref = ref 
158   
159 -    def set_mass(self, value, com=None): 
160          """Set the mass of the body""" 
161          MANAGER.add_argument(self, "mass", value, com) 
162       
163 -    def set_center_of_mass(self, *args, **kargs): 
164          """Set the relative center of mass for the body 
165          according to the node reference frame""" 
166          MANAGER.add_vector(self, "center_of_mass", args, kargs) 
167   
168 -    def set_inertia_matrix(self, *args, **kargs): 
169          """Set the inertia matrix on the body, by default 
170          in the node reference frame""" 
171          MANAGER.add_matrix(self, "inertia_matrix", args, kargs) 
172   
173   
174  ELEM_CLASS["BODY"]["Body"] =  Body 
175