{
  "engine": "Project Chrono / PyChrono FEA and SMC contact",
  "engine_version": "9.0.1",
  "mesher": "Gmsh",
  "mesher_version": "4.14.1",
  "experiment": "STEP-derived leaf stiffness in a reduced-order impact contact",
  "material_density_kg_m3": 1200.0,
  "young_modulus_Pa": 2000000000.0,
  "poisson_ratio": 0.3,
  "fea_probe_force_N": -100.0,
  "mesh_sizes_mm": [2.0, 1.5],
  "impactor_mass_kg": 0.5,
  "impactor_radius_m": 0.01,
  "impactor_initial_center_y_m": 0.015,
  "impactor_initial_speed_m_s": 1.0,
  "reference_compression_m": 0.001,
  "contact_damping_ratio": 0.2,
  "impact_duration_s": 0.04,
  "impact_time_step_s": 0.00001,
  "minimum_baseline_peak_force_N": 220.0,
  "required_relative_peak_force_reduction": 0.1,
  "maximum_impact_stroke_m": 0.0032,
  "minimum_rebound_speed_m_s": 0.9,
  "maximum_rebound_speed_m_s": 1.05,
  "maximum_relative_mesh_stiffness_change": 0.09,
  "maximum_mesh_improvement_spread": 0.03,
  "maximum_relative_mass_change": 1e-6,
  "maximum_end_pad_missing_mm3": 0.0001,
  "maximum_end_pad_excess_mm3": 0.0001,
  "maximum_envelope_excess_mm3": 0.0001
}