NodeToNodeElements with DLFT formulation package

DLFTElements subpackage

This subpackage implements a formulation of element that differs from the classical elements using DLFT [1].

DLFTElement

The DLFT method is a penalisation method for handling constraints. The DLFTElement is a modification of the NodeToNodeElement that complies with DLFT method peculiarities (thus remaining an abstract class). For a better understanding of DLFT method and its use see. All the NodeToNodeElement that uses DLFT must inherit from DLFTElement implementation as their residual value depends on the residual of the linear part of the system.

Redefined methods for complying with DLFT peculiarities are the following :

• _evalJaco_DF : for taking into account that DLFT needs the linear residual value in order to be computed

• __flag_update__ : to set flag_DLFT to True

DLFTUniGap DLFTUniGap

This DLFTElement is the implementation of PenaltyUnilateralGap element using DLFT method. More details can be viewed in [1] if needed.

Parameter	Use	Default
eps	Value of the penalisation coefficient [float]	✗
g	Size of the gap [float]	✗
N0	Normal force to the contact without forcing [float]	✗

DLFTBilateralGap ``

This DLFTElement is the implementation of PenaltyBilateralGap element using DLFT method. More details can be viewed in [1] if needed.

Parameter	Use	Default
eps	Value of the penalisation coefficient [float]	✗
g	Size of the gap [float]	✗

DLFTFriction DLFTFriction

This DLFTElement is the implementation of Jenkins element using DLFT method. More details can be viewed in [1] if needed.

Parameter	Use	Default
eps	Value of the penalisation coefficient [float]	✗
mu	friction coefficient [float]	✗
N0	Normal force to the contact at initial state [float]	✗

DLFT3D

This DLFTElement is the implementation of Penalty3D element using DLFT method. It is an assembly of DLFTUniGap and DLFTFriction residual and jacobian. More details can be viewed in [1] if needed.

Parameter	Use	Default
eps	Value of the penalisation coefficient [float]	✗
g	Size of the gap [float]	✗
mu	friction coefficient [float]	✗
N0	Normal force to the contact at initial state [float]	✗

References

[1] S. Nacivet, Modélisation du frottement en pied d’aube par une approche fréquentielle. PhD manuscript École Centrale de Lyon, 2002.

API links

pyHarm.Elements.NodeToNodeElements.DLFTElements