Roll Pass Units
The roll pass is the most important unit, since forming of the workpiece is happening here.
It is represented by the RollPass class.
The RollPass constructor takes a Roll object, which is defining the properties of the working rolls including the groove.
Read the following sections for detailed information on those.
To create a roll pass, one must create three objects: a groove, a roll and finally the roll pass itself. The groove object defines the contour line of the roll surface. The roll object defines the geometry and kinetics of the roll and needs a groove object for creation. The roll object holds also solution data like the contact area and roll torque. The roll pass object itself defines the placement of the rolls and holds solution logic and data. A most basic roll pass creation code would look like this:
RollPass(
label="My First Roll Pass", # give it a name for human recognition
roll=Roll( # the roll object constructor
groove=CircularOvalGroove( # the groove object constructor
# parameters of the groove geometry
depth=8e-3,
r1=6e-3,
r2=40e-3
),
# properties of the roll
nominal_radius=160e-3,
rotational_frequency=1,
...
),
# properties of the roll pass
gap=2e-3,
)
For information on which keyword arguments can be given, see the respective class documentations of RollPass, Roll and the different grooves.
In reversing mills, the workpiece is commonly rotated by 90° before feeding it into the next roll pass. In continuous mills, however, often rolling stands are constructed alternating in a horizontal/vertical manner. Currently, PyRolL only supports horizontal rolling stands, since the support for vertical ones would introduce certain complexity for model implementation. So, the profile must be rotated for reversing, as well as, continuous pass sequences. For the classic pass sequences, PyRolL knows the common rotation angle and applies it automatically. However, the user can influence and override this behavior. Rotation achieved by the use of a helper unit, see the section on rotators for detailed information on this topic.
- class RollPass(roll: Roll, label: str = '', **kwargs)
Represents a roll pass with two symmetric working rolls.
- Parameters:
roll – the roll object representing the equal working rolls of the pass
label – label for human identification
kwargs – additional hook values as keyword arguments to set explicitly
- class DiskElement(parent: Unit, index: int, **kwargs)
Represents a disk element in a roll pass.
- Parameters:
label – label for human identification
kwargs – additional hook values as keyword arguments to set explicitly
- abs_draught
Absolute draught (change in height).
- abs_elongation
Absolute elongation (change in length).
- abs_spread
Absolute spread (change in width).
- contact_area
Area of contact of the workpiece to the rolls.
- deformation_resistance
Equivalent deformation resistance (mean flow stress increased by deformation efficiency).
- draught
Coefficient of draught (change in height).
- duration
Time needed to pass the unit (temporal extent).
- elongation
Coefficient of elongation (change in length).
- energy_consumption
Energy consumption of this unit per produced mass.
- free_surface_area
Area of free surface.
- iteration_precision
Precision of iteration break in solution loop.
- length
The length of the unit (spacial extent in rolling direction).
- log_draught
Log. coefficient of draught (change in height).
- log_elongation
Log. coefficient of elongation (change in length).
- log_spread
Log. coefficient of spread (change in width).
- mass_flux
Flux/throughput of mass through this unit.
- max_iteration_count
Count of maximum solution loop iterations before aborting.
- power
Total energy demand per time of this unit.
- rel_draught
Relative draught (change in height).
- rel_elongation
Relative elongation (change in length).
- rel_spread
Relative spread (change in width).
- spread
Coefficient of spread (change in width).
- strain
Mean equivalent strain applied to the workpiece.
- strain_rate
Mean equivalent strain rate.
- surface_area
Surface area of workpiece within the unit.
- velocity
Mean velocity of material flow.
- volume
Volume of workpiece material within the unit.
- volume_flux
Flux/throughput of volume through this unit.
- init_solve(in_profile: Profile)
Method called by the standard
solve()implementation to init the specialized profile instances for in and out.- Parameters:
in_profile – the incoming state passed to
solve()
- plot(**kwargs)
Returns a matplotlib figure visualizing this instance. It is not required to implement this method. :param kwargs: keyword arguments passed to the figure constructor
- Raises:
RuntimeError – if matplotlib is not importable
TypeError – if the current type does not support plotting
- reevaluate_cache()
Clears the cache of hook function results.
- abs_draught
Absolute draught (change in height).
- abs_elongation
Absolute elongation (change in length).
- abs_spread
Absolute spread (change in width).
- back_tension
Back tension acting on the current roll pass.
- property classifiers
A tuple of keywords to specify the shape type classifiers of this roll pass. Shortcut to
self.groove.classifiers.
- contact_area
Area of contact of the workpiece to the rolls.
- property contour_lines: List[LineString]
List of line strings bounding the roll pass at the high point.
- deformation_resistance
Equivalent deformation resistance (mean flow stress increased by deformation efficiency).
- disk_element_count
Number of intermediate profiles to create during unit solution (in and out profiles are not counted within).
- property disk_elements: List[DiskElement]
A list of disk elements used to subdivide this unit.
- displaced_cross_section
Cross-section of the roll pass witch is displaced due to elongation and won’t reappear in the next roll-pass.
- draught
Coefficient of draught (change in height).
- duration
Time needed to pass the unit (temporal extent).
- elongation
Coefficient of elongation (change in length).
- elongation_efficiency
Efficiency of a roll pass to elongate a incoming profile.
- energy_consumption
Energy consumption of this unit per produced mass.
- entry_angle
Angle at which the material enters the roll gap.
- entry_point
Point where the material enters the roll gap.
- exit_angle
Angle at which the material exits the roll gap.
- exit_point
Point where the material exits the roll gap.
- forward_slip_ratio
Ratio of forward slip of the roll gap.
- free_surface_area
Area of free surface.
- front_tension
Front tension acting on the current roll pass.
- gap
Gap between the rolls (outer surface).
- height
Maximum height of the roll pass.
- iteration_precision
Precision of iteration break in solution loop.
- length
The length of the unit (spacial extent in rolling direction).
- log_draught
Log. coefficient of draught (change in height).
- log_elongation
Log. coefficient of elongation (change in length).
- log_spread
Log. coefficient of spread (change in width).
- mass_flux
Flux/throughput of mass through this unit.
- max_iteration_count
Count of maximum solution loop iterations before aborting.
- orientation
Orientation of the roll pass for displaying purposes. Meaning of height and width always refer to standard horizontal orientation anyway. Commonly 0 (horizontal) or 90 (vertical) for two-roll passes. Other integer values are supported, too.
- power
Total energy demand per time of this unit.
- reappearing_cross_section
Cross-section of the roll pass witch appears again in the next roll-pass due to spreading.
- rel_draught
Relative draught (change in height).
- rel_elongation
Relative elongation (change in length).
- rel_spread
Relative spread (change in width).
- roll
The working roll of this pass (equal upper and lower).
- roll_force
Vertical roll force.
- rotation
Rotation applied to the incoming profile in ° (degree) before entry in this roll pass. Alternatively, provide a boolean value: false equals 0, true means automatic determination from hook functions of
Rotator.rotation.
- spread
Coefficient of spread (change in width).
- strain
Mean equivalent strain applied to the workpiece.
- strain_rate
Mean equivalent strain rate.
- surface_area
Surface area of workpiece within the unit.
- target_cross_section_area
Target cross-section of the out profile.
- target_cross_section_filling_ratio
Target cross-section filling ratio of the out profile.
- target_filling_ratio
Target filling ratio of the out profile.
- target_width
Target width of the out profile.
- tip_cross_section
Cross-section of the roll pass at filling with its tip width.
- tip_width
Width of the intersection of the extended groove flanks (theoretical maximum filling width).
- usable_cross_section
Cross-section of the roll pass at ideal filling with its usable width.
- usable_width
Usable width (width of ideal filling). Equals the usable width of the groove for two-roll passes, but deviates for three and four-roll passes.
- velocity
Mean velocity of material flow.
- volume
Volume of workpiece material within the unit.
- volume_flux
Flux/throughput of volume through this unit.