{
  "engine": "Project Chrono / PyChrono",
  "engine_version": "9.0.1",
  "experiment": "CAD-derived spring attachment on a payload catapult",
  "material_density_kg_m3": 7800.0,
  "payload_mass_kg": 1.0,
  "gravity_m_s2": 9.81,
  "spring_stiffness_N_m": 100.0,
  "spring_preload_N": 30.0,
  "pivot_damping_N_m_s_rad": 0.005,
  "initial_angle_rad": -0.7853981633974483,
  "release_angle_rad": 0.0,
  "duration_s": 0.5,
  "time_step_s": 0.0005,
  "minimum_baseline_release_speed_m_s": 0.4,
  "required_relative_release_speed_gain": 0.5,
  "maximum_peak_pivot_reaction_N": 25.0,
  "minimum_spring_seat_x_mm": 45.0,
  "maximum_spring_seat_x_mm": 85.0,
  "maximum_spring_seat_y_mm": 0.000001,
  "maximum_relative_mass_change": 1e-6,
  "maximum_envelope_change_mm": 1e-6,
  "maximum_fixed_hole_shift_mm": 1e-6,
  "maximum_fixed_bore_intrusion_mm3": 0.0001
}