Contact — Disc Brake Caliper Clamping & Friction Torque

Two-sided disc brake caliper clamping contact: normal pad clamping force equilibrium and resulting friction braking torque.

Tolerance:

5%

Problem statement

Geometry

Cast iron rotor sector (60 deg, R_in=45 mm, R_out=140 mm, thickness=12 mm) clamped by front and rear semi-metallic brake pads (36 deg sector, R_in=82 mm, R_out=130 mm, pad area A=3196.88 mm2, effective friction radius rm=107.81 mm). Piston pressure p=8 MPa applied to rear surfaces of both pads.

Material

Rotor: EN-GJL-250 Gray Cast Iron (E=110 GPa, nu=0.26). Pads: Semi-metallic friction compound (E=15 GPa, nu=0.25). Frictionless mortar contact clamping with friction torque analysis (mu=0.35).

Boundary conditions

Fix disc hub inner bore (surface number 4). Radial sector stops (surface number 5, 6 component=normal). Caliper slider guides for front pad (surface number 28, 30, 31, 32 component=normal) and rear pad (surface number 54, 56, 57, 58 component=normal). Hydraulic piston pressure 8 MPa on surface number 29 and surface num… show full text

Fix disc hub inner bore (surface number 4). Radial sector stops (surface number 5, 6 component=normal). Caliper slider guides for front pad (surface number 28, 30, 31, 32 component=normal) and rear pad (surface number 54, 56, 57, 58 component=normal). Hydraulic piston pressure 8 MPa on surface number 29 and surface number 53.

Measured quantity

Normal clamping force balance Fn = p * A = 25575.1 N per pad (total normal clamp 51150.2 N, deviation <= 5%); friction braking torque balance T_brake = 2 * mu * Fn * rm = 1930.1 N*m (for mu=0.35, rm=107.81 mm).

WebCAE Terminal

units mm
material E=110000000000 nu=0.26 density=7200
import path="disc_brake_contact_body1.step" format=step
material E=15000000000 nu=0.25 density=2800
import path="disc_brake_contact_body2.step" format=step
material E=15000000000 nu=0.25 density=2800
import path="disc_brake_contact_body3.step" format=step
contact frictionless
mesh tet size=3.5 order=2 bonding=0
fix surface number 4
fix surface number 5 component=normal
fix surface number 6 component=normal
fix surface number 31 component=normal
fix surface number 32 component=normal
fix surface number 28 component=normal
fix surface number 30 component=normal
fix surface number 57 component=normal
fix surface number 58 component=normal
fix surface number 54 component=normal
fix surface number 56 component=normal
load surface number 29 pressure=8000000
load surface number 53 pressure=8000000
solve
minmax displacement_magnitude

Results comparison

Updated: 2026-10-19 · WebCAE solver