Rolls
A roll object represents a working roll within a roll pass. Its surface shape is defined by a groove object. The current implementation of roll passes only works with symmetrical roll gaps, therefore only one roll object is needed. The groove shape is considered to be symmetric, too. This is especially true for groove types derived from the generic elongation groove. For grooves constructed using the spline groove, this has to be ensured by the user, or results may be wrong. Due to the presence of a groove, different radii can be defined for the roll object. These can be seen in the figure below:
Different Radii at a work roll.
The most important radius is the so-called working radius. This radius is defined is the corresponding radius for the equivalent flat pass method. Further, the nominal radius is defined as the outer radius at the barrel surface.
- class Roll(groove: GrooveBase, **kwargs)
Represents a roll.
- Parameters:
groove – the groove object defining the shape of the roll’s surface
kwargs – additional hook values as keyword arguments to set explicitly
- reevaluate_cache()
Clears the cache of hook function results.
- surface_interpolation(x: float | ndarray, z: float | ndarray) float | ndarray
Calculate the linear interpolation of the roll surface at the given points.
xandzmay be floats or 1D numpy arrays. Scalar values are automatically broadcasted.- Parameters:
x – x-coordinates (length direction)
z – z-coordinates (width direction)
- Returns:
the interpolated values in an array of shape
(len(x), len(z))
- center
Center point of the roll as 1D array.
- coefficient_of_thermal_expansion
Coefficient of thermal expansion of the roll material.
- contact_area
Total area of contact between roll and workpiece.
- contact_duration
Time a surface point of the roll is in contact with the material surface.
- contact_length
Length of the longest contact arc between roll and workpiece.
- property contour_line: LineString
Line string of the contour points.
- contour_points
Points of the contour line in the z-y-plane.
- core_temperature
Effective core temperature.
- density
Density (specific weight) of the roll material.
- elastic_modulus
Elastic modulus of the roll material.
- groove
The groove object defining the shape of the roll’s surface.
- heat_penetration_number
Mean heat penetration number of the roll material.
- idle_duration
Time the roll is not in
- material
String or sequence of strings classifying the material of the roll. Can be used by material databases to retrieve respective data.
- max_radius
Maximum radius (at highest point of groove).
- min_radius
Minimum radius (at lowest point of groove).
- neutral_angle
Angle at the roll surface where the shear stress is zero.
- neutral_point
Point at the roll surface where the shear stress is zero.
- nominal_diameter
Nominal diameter.
- nominal_radius
Nominal radius.
- peclet_number
Peclet number.
- poissons_ratio
Poisson’s ratio of the roll material.
- roll_power
Roll power of single roll.
- roll_torque
Roll torque of single roll.
- rotational_frequency
Rotational frequency (revolutions per time).
- specific_heat_capacity
Specific heat capacity of the roll material.
- surface_temperature
Effective surface temperature.
- surface_velocity
Tangential velocity of the outer roll surface (at nominal radius).
- surface_x
X-Coordinates of the surface interpolation grid. Array of shape (n,).
- surface_y
Y-Values of the surface interpolation grid. Array of shape (n, m), where
n = len(self.surface_x)andm = len(self.surface_z).
- surface_z
Z-Coordinates of the surface interpolation grid. Array of shape (m,).
- temperature
Mean temperature.
- temperature_field
Temperature field inside the roll body.
- thermal_conductivity
Thermal conductivity of the roll material.
- thermal_diffusivity
Mean thermal diffusivity of the roll material.
- thermal_stress_field
Thermal stress field inside the roll body.
- width
The width of the roll face.
- working_radius
Effective working radius (equivalent flat rolling).
- working_velocity
Tangential velocity of the roll surface (at working radius).
- yield_strength
Yield strength of the roll material.