Description
Simple finite element with two nodes and a bar that connects them.
No bending and torsion stiffness, just like a bar with two spherical joints. In practical terms, this element works a bit like the class ChElementSpring, but also adds mass along the element, hence point-like mass in the two nodes is not needed.
#include <ChElementBar.h>
Public Member Functions | |
virtual int | GetNnodes () override |
Gets the number of nodes used by this element. | |
virtual int | GetNdofs () override |
Gets the number of coordinates in the field used by the referenced nodes. More... | |
virtual int | GetNodeNdofs (int n) override |
Get the number of coordinates from the n-th node that are used by this element. More... | |
virtual std::shared_ptr< ChNodeFEAbase > | GetNodeN (int n) override |
Access the nth node. | |
virtual void | SetNodes (std::shared_ptr< ChNodeFEAxyz > nodeA, std::shared_ptr< ChNodeFEAxyz > nodeB) |
virtual void | GetStateBlock (ChVectorDynamic<> &mD) override |
Fills the D vector with the current field values at the nodes of the element, with proper ordering. More... | |
virtual void | ComputeKRMmatricesGlobal (ChMatrixRef H, double Kfactor, double Rfactor=0, double Mfactor=0) override |
Sets H as the global stiffness matrix K, scaled by Kfactor. More... | |
virtual void | ComputeInternalForces (ChVectorDynamic<> &Fi) override |
Computes the internal forces (ex. More... | |
void | SetBarArea (double ma) |
Set the cross sectional area of the bar (m^2) (also changes stiffness keeping same E modulus) | |
double | GetBarArea () |
void | SetBarDensity (double md) |
Set the density of the bar (kg/m^3) | |
double | GetBarDensity () |
void | SetBarYoungModulus (double mE) |
Set the Young elastic modulus (N/m^2) (also sets stiffness) | |
double | GetBarYoungModulus () |
void | SetBarRaleyghDamping (double mr) |
Set the Rayleigh damping ratio r (as in: R = r * K ) | |
double | GetBarRaleyghDamping () |
double | GetMass () |
The full mass of the bar. | |
double | GetRestLength () |
The rest length of the bar. | |
double | GetCurrentLength () |
The current length of the bar (might be after deformation) | |
double | GetStrain () |
Get the strain (epsilon), after deformation. | |
double | GetStress () |
Get the elastic stress (sigma), after deformation. | |
virtual double | GetCurrentForce () |
Get the current force transmitted along the bar direction, including the effect of the damper. More... | |
Public Member Functions inherited from chrono::fea::ChElementGeneric | |
ChKblockGeneric & | Kstiffness () |
Access the proxy to stiffness, for sparse solver. | |
virtual void | EleIntLoadResidual_F (ChVectorDynamic<> &R, const double c) override |
(This is a default (a bit unoptimal) book keeping so that in children classes you can avoid implementing this EleIntLoadResidual_F function, unless you need faster code) | |
virtual void | EleIntLoadResidual_Mv (ChVectorDynamic<> &R, const ChVectorDynamic<> &w, const double c) override |
(This is a default (VERY UNOPTIMAL) book keeping so that in children classes you can avoid implementing this EleIntLoadResidual_Mv function, unless you need faster code.) | |
virtual void | ComputeMmatrixGlobal (ChMatrixRef M) override |
Returns the global mass matrix. More... | |
virtual void | InjectKRMmatrices (ChSystemDescriptor &mdescriptor) override |
Tell to a system descriptor that there are item(s) of type ChKblock in this object (for further passing it to a solver) | |
virtual void | KRMmatricesLoad (double Kfactor, double Rfactor, double Mfactor) override |
Adds the current stiffness K and damping R and mass M matrices in encapsulated ChKblock item(s), if any. More... | |
virtual void | VariablesFbLoadInternalForces (double factor=1.) override |
Adds the internal forces, expressed as nodal forces, into the encapsulated ChVariables, in the 'fb' part: qf+=forces*factor (This is a default (a bit unoptimal) book keeping so that in children classes you can avoid implementing this VariablesFbLoadInternalForces function, unless you need faster code) | |
virtual void | VariablesFbIncrementMq () override |
Adds M*q (internal masses multiplied current 'qb') to Fb, ex. More... | |
Public Member Functions inherited from chrono::fea::ChElementBase | |
virtual void | ComputeNodalMass () |
Compute element's nodal masses. | |
virtual void | Update () |
Update: this is called at least at each time step. More... | |
virtual void | EleDoIntegration () |
This is optionally implemented if there is some internal state that requires integration. | |
Additional Inherited Members | |
Protected Attributes inherited from chrono::fea::ChElementGeneric | |
ChKblockGeneric | Kmatr |
Member Function Documentation
◆ ComputeInternalForces()
|
overridevirtual |
Computes the internal forces (ex.
the actual position of nodes is not in relaxed reference position) and set values in the Fi vector.
Implements chrono::fea::ChElementBase.
◆ ComputeKRMmatricesGlobal()
|
overridevirtual |
Sets H as the global stiffness matrix K, scaled by Kfactor.
Optionally, also superimposes global damping matrix R, scaled by Rfactor, and global mass matrix M multiplied by Mfactor. (For the spring matrix there is no need to corotate local matrices: we already know a closed form expression.)
Implements chrono::fea::ChElementBase.
◆ GetCurrentForce()
|
virtual |
Get the current force transmitted along the bar direction, including the effect of the damper.
Positive if pulled. (N)
◆ GetNdofs()
|
inlineoverridevirtual |
Gets the number of coordinates in the field used by the referenced nodes.
This is for example the size (n.of rows/columns) of the local stiffness matrix.
Implements chrono::fea::ChElementBase.
◆ GetNodeNdofs()
|
inlineoverridevirtual |
Get the number of coordinates from the n-th node that are used by this element.
Note that this may be different from the value returned by GetNodeN(n)->Get_ndof_w();
Implements chrono::fea::ChElementBase.
◆ GetStateBlock()
|
overridevirtual |
Fills the D vector with the current field values at the nodes of the element, with proper ordering.
If the D vector size is not this->GetNdofs(), it will be resized.
Implements chrono::fea::ChElementBase.
The documentation for this class was generated from the following files:
- /builds/uwsbel/chrono/src/chrono/fea/ChElementBar.h
- /builds/uwsbel/chrono/src/chrono/fea/ChElementBar.cpp