Biomechanical Model And Injury Mechanism Of Occupant Lumbar Spine In Frontal Impact

Advanced safety designs in newer cars generally provide more protections for occupants than older cars.However,recent field data analysis has shown that lumbar spine fractures has increased every year.But as lack of the spine injury evaluation criteria and test methods,the mechanism of lumbar spine fractures in frontal crashes is still unknown.A biomechanical lumbar spine finite element model was proposed and validated firstly.Effects of impact factors on lumbar spine injuries under simplified frontal impact was studied.Impact velocity had significantly influence on lumbar spine injuries(P=0.009).Except impact velocity,seat cushion thickness had significantly influence on lumbar spine injuries(P=0.039).A parametric lumbar spine finite element model was proposed based on validated biomechanical lumbar spine model and 82 real human lumbar CT data.The parametric lumbar spine model could account effects of human factors(age,sex,height,BMI and lumbar spine curvature)on lumbar spine geometric size and shape.The parametric lumbar geometrical model could predict lumbar spine geometry accurately.Based on the parametric lumbar spine model,effects of human factors on lumbar spine geometry were analyzed.Effects of human factors on lumbar spine injuries were performed with a simplified frontal impacted finite element model.Through mesh morphing,the whole human body model with biomechanical lumbar spine was proposed.Additional simulations were performed to study effects of crash pulses,restrained system factors,and human factors on lumbar spine injuries under frontal impact.Results demonstrated that decreasing seatbelt stiffness,adding seatbelt locking tongue,lap belt pretensioner,deleting shoulder belt pretensioner,moving seatbelt anchor point back could decrease risk of lumbar spine injuries under frontal impact.The biomechanical lumbar spine finite element model and parametric lumbar spine model could be used to study the injury mechanism and protection of occupant under frontal impact.The success of this study will address the mechanism of lumbar injury and provide better understanding of how to design countermeasures to reduce occupant injuries in new generation of vehicle models.