Thickness Disturbance Simulator

Rolling mill working point · Exit-gauge changes · Disturbance envelope

ENGINEERING PROTOTYPE · SERVER CALCULATED

Model note: The material stiffness shown here is −dF_roll/dh_out, not Young's modulus. The effective unloaded mill-gap intercept is calibrated to the selected nominal working point and may include a negative zero offset. Hold it fixed while exploring process disturbances.

01 / Nominal operating condition

Set the starting point. Changes below are applied only when you press Set nominal.

Steel grade

Entry thickness (mm)

Exit thickness (mm)

Width (mm)

Work roll Ø (mm)

Mill modulus (kN/mm)

Initial cold work (%)

Entry tension (kN)

Exit tension (kN)

Friction µ

Ready

Force comes from the same numerical rolling model as the Sergafat force calculator, including cold work, strip tensions and roll flattening.

02 / Live condition changes

Move one or several controls. The nominal curves stay frozen, revealing the shift in the operating point.

03 / Disturbance half-ranges

Each range defines ± variation around nominal. The sampled envelope combines their simultaneous extremes.

Gap variation represents an HGC effective-gap disturbance; with it at zero, only the material curve moves.

Nominal force—Baseline

Current force—ΔF —

Current exit thickness—Δh —

Material stiffness |dF/dh|—Mill: —

Mill line & material stiffness curve

X = exit thickness (mm) · Y = rolling force (MN)

Mill spring lineNominal material curveChanged material curveWorking point

The effective gap stays constant unless you apply an HGC gap variation.

Working-point sensitivity envelope

Magnified view of force and exit-thickness movement

NominalCurrentSampled envelope

The envelope is a sample-based approximation, not a guaranteed global limit.

Parameter sensitivity at the nominal working point

Each row applies the indicated positive and negative disturbance independently, holding the other inputs fixed.

Changed parameter	Range (±)	Δh for positive change	ΔF for positive change	Local dh / unit

Interpretation: Changing the mill gap shifts the machine line; entry gauge, tensions, friction and flow-stress strength shift the process curve. The actual thickness and force are found at their new intersection. The material stiffness is the local magnitude of the process curve slope. Sampled extremes are illustrative and are not certified machine capability limits.