Clutch/Brake Torque Capacity Calculator mechanism

Model scope

The arithmetic and both stated formulas are standard under their respective assumptions. Verdict is NEEDS_REVIEW because the wear-model selection and the exact meaning of n are not fully specified. The third vector exposes a unit-conversion trap; its corrected result is 56.25 N·m, not 506.25 N·m.

• The formulas are standard and correct only when n means the number of active friction surfaces and F means the total axial clamping force acting on the friction pack.
• The specification provides both uniform-wear and uniform-pressure formulas but does not define an input or rule for selecting which wear model to use; the computed result is therefore ambiguous.
• The common alternative convention counts friction pairs rather than friction surfaces, so the definition of n must be explicit in the interface and documentation.

Units and conventions

• μ is dimensionless.
• F is in newtons.
• ro and ri are radii, not diameters, and must use the same length unit.
• The resulting torque T is in force-length units; with F in newtons and radii in metres, T is in N·m.
• For the uniform-wear model, r_eff=(ro+ri)/2 assumes ri<ro and a physically valid annular friction surface.
• For the uniform-pressure model, r_eff=(2/3)(ro³-ri³)/(ro²-ri²) assumes ri<ro and consistent length units.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "mu": 0.3,
    "F_N": 4000,
    "ro_m": 0.15,
    "ri_m": 0.08,
    "n_friction_surfaces": 2,
    "wear_model": "uniform_wear"
  },
  "expected_outputs": {
    "T_Nm": 276
  },
  "working": "r_eff=(ro+ri)/2=(0.15+0.08)/2=0.23/2=0.115 m. T=n·μ·F·r_eff=2·0.3·4000·0.115=0.6·4000·0.115=2400·0.115=276 N·m."
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The uniform-pressure formula becomes undefined when ro=ri because its denominator ro^2-ri^2 is zero. The instrument should reject that geometry rather than return a numeric torque. Additional hazards are the physically invalid n=0 boundary, the unspecified branch-selection criterion, and the sign convention for axial force and torque.

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche5/tranche5-results.json
• BOUNDARY_HAZARD_CATALOG.json