api/aspherix_contact_model_external.h

This is the header file used to derive a new contact model which must be derived from this class. The member functions are:

ContactModelExternal 

Constructor. Call connectToAspherix at the end of it.

addHistoryValues 

This function in which addHistoryValue and addHistoryVector should be called can be overwritten by the user (virtual function) to set the history values of the contact model.

registerGlobalProperties 

This function in which the register* functions should be called can be overwritten by the user (virtual function) to request global properties from the simulation.

This function is used to specify the maximum distance between two particle centers for which a non-zero force is expected. This is used to set the contact distance factor which determines how the neighbor lists are built. The global minimum of this value is twice the maximum particle radius. If your contact model requires force calculation (using surfacesClose) of non-touching particles then this value needs to be calculated accordingly. The value of this parameter is inversely proportional to the simulation efficiency, i.e. large values result in slow simulations.

surfacesIntersect 

The function that determines what happens when two particles are in contact with each other and it can be overwritten by the user (virtual function). This function should calculate the force that acts between two particles in contact.

surfacesClose 

The function that determines what happens when two particles are close to each other (not touching) and it can be overwritten by the user (virtual function). This function should calculate the force that acts between two particles in the vicinity of each other.

beginPass 

This function is called before the loop over all particle pairs and can be used to set some general member variables, it can be overwritten by the user (virtual function).

endPass 

This function is called after the loop over all particle pairs and can be used to finalize some calculation (e.g. sum) during the neighbor calculation, it can be overwritten by the user (virtual function).

registerOnOff 

Registers a setting that can be passed to the contact model that is of bool type.

registerDouble 

Registers a setting that can be passed to the contact model that is of double type.

registerString 

Registers a setting that can be passed to the contact model that is of string type.

getRegisterOnOff 

Gets the value of a boolean that was set via the contact model settings.

getRegisterDouble 

Gets the value of a double that was set via the contact model settings.

getRegisterString 

Gets the value of a string that was set via the contact model settings.

addHistoryValue 

Adds a scalar history value for each particle interaction. If the newtonflag argument is true then the sign will be switched when the internal particle ordering changes from i->j to j->i.

addHistoryVector 

Adds a vector history value for each particle interaction. If the newtonflag argument is true then the sign will be switched when the internal particle ordering changes from i->j to j->i (example: shear vector).

connectToAspherix 

This function must be called in the constructor to connect the contact model to Aspherix®.

registerScalarProperty 

Registers a scalar Property (see global_scalar command)

registerTypeProperty 

Register a material property (see material_properties command). Note, the type integer refers to the material with that index (starting at 1) of the materials command list. This function returns an index which can be used for fast access of the properties using the getTypeProperty function.

registerPairProperty 

Registers a material interaction property (see material_interaction_properties command). Note, the type integers refer to the material with those indices (starting at 1) of the materials command list. This function returns an index which can be used for fast access of the properties using the getPairProperty function.

getScalarProperty 

Gets the value of a previously registered scalar property.

getTypeProperty 

Gets the value of a previously registered type property. This function can be called either with the property name as string or with the index provided by the registerTypeProperty function. Note that the latter is significantly faster and should be used if this function is called within the inner loops (i.e. surfacesIntersect and surfacesClose).

getPairProperty 

Gets the value of a previously registered interaction pair property. This function can be called either with the property name as string or with the index provided by the registerPairProperty function. Note that the latter is significantly faster and should be used if this function is called within the inner loops (i.e. surfacesIntersect and surfacesClose).