Substructures package¶

Package Substructures¶

This package contains all the substructures types that are provided by pyHarm. The module is organized around an abstract class ABCSubstructure and a FactorySubstructure that is in charge of instantiating the objects. All system objects must comply with the ABCSubstructure abstract class. The main purpose of ABCSubstructure based classes is to generate a DataFrame and create the degrees of freedom. Additionaly the ABCSubstructure based classes can generate a dictionary that describes connectors or kinematic conditions to add to the ABCSystem.

The section below presents the different modules that are available.

ABCSubstructure¶

The ABCSubstructure class is an abstract class defining the essential components of any substructure. Two abstract methods are mandatory :

Methods	Use
`factory_keyword`	Abstract property : keyword used in the factory to call instantiation of a class
`_add_connectors`	Abstract method : Returns a dictionary containing connectors to add to the problem
`_add_kinematics`	Abstract method : Returns a dictionary containing kinematic conditions to add to the problem

Examples of creating an `ABCSubstructure` and adding it into an input dictionary:¶

To be created, an ABCSubstructure subclass needs its abstract methods to be defined :

class FakeSubstructure(ABCStopCriterion): # inherits from abstract class
    factory_keyword="fakesub" # mandatory to define
    def _add_connectors(self,data:dict):
        con = {
            'connector_001':{
                'type':'LinearSpring',
                'connect':{self.name:[0],'INTERNAL':[1]},
                'dirs':[0,2],
                'k':1e9
            },
            'connector_002':{
                ...
            }
        }
        return con
    def _add_kinematics(self,data:dict):
        kin = {
            'kin_001':{
                'type':'AccelImposed',
                'connect':{self.name:[10]},
                'dirs':[1],
                'amp':.1
            }
        }
        return kin

INP = {
    "substructure":{
        "substructure_001":{
            "type":"fakesub", # calls the reader using factory_keyword.
            ...,
        },
        ...,
    },
    "plugin":[FakeSubstructure], # adds to the factory using plugin
    ...,
}

OnlyDofs `onlydofs`¶

The OnlyDofs class is here to create dofs into the system, but does not create any new connectors or kinematic conditions. The mandatory parameters are ndofs, nnodes, nmodes. If nmodes is not provided, it is set to default 0.

Parameter	Use	Default
`nnodes`	number of nodes [int]	✗
`ndofs`	number of dofs per node [int]	✗
`nmodes`	Number of modes [int]	✓ : 0

Substructure `substructure`¶

The Substructure class is the basic class of pyHarm to create dofs and add a Substructure Element to the System. The Substructure needs the matrices M,G,C,K, to be defined in order to be built as well as the number of dof per node ndofs. The other characteristics can be guessed. When using super-elements, the number of modes nmodes must be provided. It is assumed that the modal nodes are placed last in the matrices.

Parameter	Use	Default
`ndofs`	number of dofs per node [int]	✗
`matrix`	contains the necessary matrices [dict[str,np.ndarray]]	✓ : if `matrix` given
`filename`	name of the file that contains the necessary matrices [str]	✓ : if `filename` given
`reader`	reader use to interpret and modify input data to the right format [ABCReader]	✓ : ‘generic’
`nmodes`	Number of modes [int]	✓ : 0
`nnodes`	number of nodes [int]	✓ : auto-computed from matrix size

Reader subpackage¶

pyHarm uses external file readers in order to parse and adapt input dictionary in the pyHarm syntax. The subpackage responsible of this is decribed below :

Data reader

SubsDataReader package

API links

pyHarm.Substructures