pyva.coupling.junctions.HybridAreaJunction

class pyva.coupling.junctions.HybridAreaJunction(systems, fem, coupling='all', trim=None)

Bases: Junction

Class for hybrid area junctions between FEM systems and cavities

systems

Type:: list of SEA systems

FEMsys

Type:: list of FEMsystems

__init__(systems, fem, coupling='all', trim=None)

Class contructor for HbridAreaJunction

Parameters:

systems (tuple, list or ndarray) – vector of SEA systems.
fem (fem) – FEM system.
coupling (str,tuple, list or ndarray, optional) – indexes defining nodes coupled to SEA subsystem. The default is ‘all’.
trim (tuple, list of TMmodel, optional) – trim layer definition. The default is None.

Return type:

None.

Methods

`CLF`(omega[, trim, force])	coupling loss factor for hybrid area junction
`FEM_response`(omega, energy)	Calculates the cross spectral resonse of the plate due to reverberant fields in SEA systems
`__init__`(systems, fem[, coupling, trim])	Class contructor for HbridAreaJunction
`get_wave_DOF`([ix])	Provides the local wave DOFs of the junction
`index`(ID)	Determines index of ID in system list of junction
`junction_matrix`(omega)	Create empty junction matrix for further calculation in daughter classes
`modal_density`(omega)	Provides modal density

Attributes

`N`	Number of connected physical SEA systems (not wave_fields)
`N_wave`	Number of wave fields
`exc_DOF`	Provides 'excitation' DOFs of junction SEA matrix
`in_dofs`	Provides input wave dofs of junction for upper triangular input matrix
`out_dofs`	Provides output wave dofs of junction for upper triangular input matrix
`res_DOF`	Provides 'response' DOFs of junction SEA matrix

CLF(omega, trim=None, force=None)

coupling loss factor for hybrid area junction

This method calculates the CLF from system i_sys[0] to i_sys[1]. The wavefields that are considered are either the pressure waves The CLF is calculated running through through both indexes

This method provides the total stiffness, thus it is efficient to perform all solutions that require the total stiffness matrix

Parameters:

omega (ndarray) – angular frequency.
trim (TMmodel, optional) – trim as layers. The default is None.
force (Load, optional) – force defined on nodes and DOFs. The default is None.
Signal (bool, optional) – switch for Signal output. The default is True.

Returns:

CLF (ndarray) – hybrid coupling loss factor
CLF_alpha (ndarray) – dymping of SEA systems due to loss in FE-system
input_power (ndarray) – power input to the SEA subsystem due to the force load
modal_displacement (ndarray) – modal displacement due to force load

FEM_response(omega, energy)

Calculates the cross spectral resonse of the plate due to reverberant fields in SEA systems

Parameters:

omega (ndarray) – angular frequency.
energy (Signal) – energy in SEA systems.

Returns:

CSD of FEM DOFs.

Return type:

ndarray

property N

Number of connected physical SEA systems (not wave_fields)

Returns:: number of systems
Return type:: int

property N_wave

Number of wave fields

Returns:: Number of wave fields
Return type:: int

property exc_DOF

Provides ‘excitation’ DOFs of junction SEA matrix

The ‘excitation’ and response DOFs are equal in terms of ID and wave_dof but use ‘power’ as physical input

Returns:: excitation DOFs of junction SEA matrix
Return type:: DOF

get_wave_DOF(ix=slice(None, None, None))

Provides the local wave DOFs of the junction

Returns:: dofs of junction, list of systems
Return type:: DOF,sys_list

property in_dofs

Provides input wave dofs of junction for upper triangular input matrix

These DOFs are requiered to determine the column index of the upper triangular components in the global SEA matrix.

For example a plate - cavity junction has wave dofs [ ID=1,dof=3 ; 1,5 ; 2,0 ]

The full of diag CLF in the SEA matrix are

$\begin{bmatrix} \Sigma & - n_{15}\eta_{15,13} & -n_{20}\eta_{20,13} \\ - n_{13}\eta_{13,15} & \Sigma & -n_{20}\eta_{20,15} \\ - n_{13}\eta_{13,20} & - n_{15}\eta_{15,20} & \Sigma \end{bmatrix}$

The column dofs would be : [ 1,5 ; 2,0 ; 2,0]