Package mbdyn :: Module nodes :: Class StructuralNode

Class StructuralNode

record.RecordBase --+            
                    |            
        record.Record --+        
                        |        
       common.BasicObject --+    
                            |    
                         Node --+
                                |
                               StructuralNode

Known Subclasses:: interface.nodes.StructuralNode

The structural node of MBDyn. The type can be 'static' or 'dynamic' as defined in MBDyn. Usually a structural node is defined relative to a ReferenceFrame; its position, rotation matrix, velocity and angular velocity are then defined. A structural node inherits from its reference frame property. It is important to understand that a structural node introduces degrees of freedom in the problem, that's why it needs to be attached to joints for getting constraints and describing a model that can be solved.

Example of use:

   import numpy as N

   ref = ReferenceFrame()
   ref.set_position(10., 0., 0.)

   node1 = StructuralNode()
   node1.set_relative_from(ref)
   node1.set_velocity(1., 0., 0.)
   node1.set_angular_velocity(0., 0., 1.)

   angle = N.pi/4.
   node2 = StructuralNode()
   node2.set_relative_from(ref)
   node2.set_type("static")
   node2.set_position(10., 0., 0.)
   node2.set_rotation_matrix(one=(1., 0., 0.),
                             two=(0., N.cos(angle), N.sin(angle)))

The node1 is at 10 m from the origin, with an initial velocity of 1 m/s along x and an initial angular velocity of 1 rad/s along z. The node2 does not have any momentum but is at 20 m from the origin and its rotation matrix is turned of π/4 along the x axis. Those nodes can then be added to the Simulation.

Instance Methods

[hide private]

__init__(self, name='structural node') source code

set_default(self)
The default node is dynamic, with a null position offset, a identity rotation matric, a null velocity offset and a null angular velocity relative to its reference frame

source code

get_mbdyn_instance(self)
Get the instance created by MBDyn when parsing the input file.

source code

init_results(self)
Create the needed objects to save the results during the simulation.

source code

set_position(self, *args, **kargs)
Set the position of the node (offset relative to its reference frame)

source code

set_rotation_matrix(self, *args, **kargs)
Set the orientation matrix of the node (relative to its reference frame)

source code

set_velocity(self, *args, **kargs)
Set the velocity of the node (relative to its reference frame)

source code

set_angular_velocity(self, *args, **kargs)
Set the angular velocity of the node (relative to its reference frame)

source code

append(self, values)
Append a MBDyn step to the results.

source code

Inherited from Node: collect_parameters, set_parameters, set_relative_from, set_type

Inherited from common.BasicObject: get_lines, set_comment, set_label, set_name, set_simulation_ref

Inherited from record.Record: common_init_results, save, set_own_parameters, will_save, will_save_nothing, will_save_only

Inherited from record.Record (private): _save_direct_results, _save_results_with_actions, _try_to_add

Inherited from record.RecordBase: collect_own_parameters, set_own_para

Inherited from record.RecordBase (private): _collect_own_para

Method Details

[hide private]

init(self, name=`'structural node'`)
(Constructor)

source code

Overrides: Node.__init__

set_default(self)

source code

The default node is dynamic, with a null position offset, a identity rotation matric, a null velocity offset and a null angular velocity relative to its reference frame