{
  "mass_kg": 120.0,
  "pitch_inertia_kg_m2": 18.0,
  "support_positions_m": [-0.42, 0.36],
  "force_position_m": 0.22,
  "sensor_position_m": 0.25,
  "stiffness_split": [1.05, 0.95],
  "unbalance_kg_m": 0.002,
  "operating_frequency_hz": [20.0, 35.0],
  "candidate_pair_stiffness_N_m": [80000, 100000, 120000, 140000, 180000, 240000],
  "candidate_damping_ratios": [0.06, 0.10, 0.14, 0.20, 0.28],
  "uncertainty": {"mass_factors": [0.9, 1.1], "cg_shift_m": [-0.04, 0.04], "stiffness_factors": [0.9, 1.1], "damping_factors": [0.8, 1.2]},
  "limits": {"static_compression_mm": 8.5, "operating_reaction_envelope_N": 18.0, "operating_sensor_acceleration_m_s2": 1.8, "decay_2percent_s": 2.0, "transient_relative_motion_mm": 2.0, "total_compression_mm": 11.0, "group_load_min_N": 0.0, "group_load_max_N": 1100.0},
  "runup": {"maximum_hz": 30.0, "ramp_s": 2.0, "hold_s": 1.0, "settle_s": 2.0},
  "bump": {"amplitude_m": 0.001, "duration_s": 0.15, "record_s": 3.0},
  "notes": "Synthetic reference skid. Two support groups represent a left/right pair of mounts each. These are assumed equivalent linear properties, not measured vendor mount data."
}