the application of madymo for simulation of occupant kinematics
TRANSCRIPT
The Application of MADYMO for Simulation of Occupant Kinematics in Accident ReconstructionOccupant Kinematics in Accident Reconstruction
Cummings Scientific, LLC
Cummings Scientific, LLC commonly uses MADYMO in the following types of accidents:
• Seatbelt Analysis
• Airbag Analysis
• FE Analysis• FE Analysis
• Rollover Accidents
• Low-Speed Rear Impacts
• Frontal Impacts
• Wheelchair Analysis
• Side Impacts
• Slip and Fall Analysis
• Motorcycle Accidents
• Helmet Analysis
• Industrial Accidents
• Child Seat Analysis
Limitations in Accident Reconstruction Data
• Calculation of delta-v (COLM, COE, Simulations)
• Calculation of delta-t (Published Data, Crash Tests, Natural Frequency)
• PDOF (Principle Direction of Force)
• Amount of available evidence and reliability of the application of evidence• Amount of available evidence and reliability of the application of evidence
• Vehicle motion in MADYMO (Acceleration Pulse, 6 DOF)
• Taking the “Conservative Approach”
• Matching Physical Evidence
Crash Pulse Characterizations applied to MADYMO
Haversine and Halfsine Acceleration Pulses
Halfsine Haversine
Average Square Wave Acceleration Pulse
Square Wave
Crash Pulse Comparison – EDR Data
Crash Pulse Comparison – MADYMO Initial Position
Crash Pulse Comparison – MADYMO Simulation
Crash Pulse Comparison – Vehicle Acceleration
Haversine = 134 m/s^2
Halfsine = 105 m/s^2
Sq. Wave = 67 m/s^2
Haversine = 89 m/s^2
Halfsine = 70 m/s^2
Sq. Wave = 45 m/s^2
Crash Pulse Comparison – Head CG Acceleration
Haversine = 252 m/s^2
Halfsine = 194 m/s^2
Sq. Wave = 153 m/s^2
Haversine = 190 m/s^2
Halfsine = 161 m/s^2
Sq. Wave = 133 m/s^2
Restraint System Comparison – MADYMO Simulation
Restraint System Comparison – Head CG Acceleration
Haversine = 252 m/s^2
Halfsine = 194 m/s^2
Sq. Wave = 153 m/s^2
Haversine = 190 m/s^2
Halfsine = 161 m/s^2
Sq. Wave = 133 m/s^2
Haversine = 938 m/s^2
Halfsine = 464 m/s^2
Child Belt Comparison – 5-point Harness vs. 3-point Belt
Child Belt Comparison – MADYMO Simulation
Child Belt Comparison – Lap Belt Contact Summation Force
Left Lap Belt = 2380 N
Right Lap Belt = 622 N
Applications of MADYMO in “pure” Accident Reconstruction
• Seat belt usage determined by physical evidence comparison
• Ejection portals
• Who was driving?
• Occupant Kinematics as a strategy for Accident Reconstruction• Occupant Kinematics as a strategy for Accident Reconstruction
• Human factors in Accident Reconstruction
Questions or nah?Questions or nah?