Date of Defense
18-6-2025 10:00 AM
Location
F1-1043
Document Type
Thesis Defense
Degree Name
Master of Science in Mechanical Engineering (MSME)
College
COE
Department
Mechanical and Aerospace Engineering
First Advisor
Dr. Kassim Abdullah
Keywords
Human body model, children, impact velocity, injury biomechanics, knee-thigh-hip complex, age, computational modelling
Abstract
Brief introduction: This thesis examined the crash impact injury outcomes of the knee-thigh-hip complex (KTH) in children based on age and impact velocity using computational modelling. Child occupant (3YO, 6YO, 10YO) Total Human Body Model for Safety (THUMS) models developed by Toyota were used to evaluate the effects of age and impact velocity on pediatric KTH crash impact response. Aims: The main objectives of this thesis are to analyze the effect of child age and impact velocity on KTH crash impact response. Methods: The knee impact simulations were performed based on different impact velocities (1.2, 3.5, 7.2, and 11.1 m/s). The knee was impacted at the middle of the knee joint, with the impactor hitting both the femur and tibia at the patella for all the three models. Simulation results were analyzed to evaluate the loading characteristics at the femur, tibia, knee, and ligaments across the 3 models. These characteristics include the peak force, absorbed energy, and peak stress. KTH loading characteristics were then evaluated for trends between the 3 different models at varying impact velocities. Results: The results of the simulations demonstrate that the child knee joint’s response to impact forces varied significantly based on the impact velocity and the age of the child model. The force-displacement diagrams provided valuable insights into how the child knee joint reacts under different impact velocities, showcasing a clear trend of increased force with higher impact velocities. These diagrams also highlighted that the child knee joint’s ability to absorb impact energy decreased with higher impact speeds which is critical for understanding injury mechanisms in real-world crash impact scenarios. The variations in force-displacement characteristics, energy absorption, and stress distributions across the three child models underscores the importance of accounting for age when evaluating knee crash impact injury risks in children. Significant contributions: This is the first study to evaluate the effects of age and impact velocity on pediatric KTH response. The findings of this study revealed that age-based intrinsic factors affect the impact response of the KTH complex in children. An understanding of child KTH crash impact injury mechanisms is important to reduce the burden of these injuries in children. Gap filled: The thesis demonstrates the importance of numerical simulations in evaluating pediatric knee joint biomechanical tolerance under crash impact conditions. The combination of various impact velocities, model age, and the analyses of key biomechanical variables provide a deeper understanding of how the child knee joint behaves under crash impact conditions thereby enhancing the assessment of KTH injuries sustained by children in vehicle crashes and their associated risk factors. These findings can be instrumental in improving vehicle safety standards and in designing vehicle crash protective systems for children.
Included in
KNEE-THIGH-HIP IMPACT IN CHILDREN: EFFECTS OF AGE AND IMPACT VELOCITY
F1-1043
Brief introduction: This thesis examined the crash impact injury outcomes of the knee-thigh-hip complex (KTH) in children based on age and impact velocity using computational modelling. Child occupant (3YO, 6YO, 10YO) Total Human Body Model for Safety (THUMS) models developed by Toyota were used to evaluate the effects of age and impact velocity on pediatric KTH crash impact response. Aims: The main objectives of this thesis are to analyze the effect of child age and impact velocity on KTH crash impact response. Methods: The knee impact simulations were performed based on different impact velocities (1.2, 3.5, 7.2, and 11.1 m/s). The knee was impacted at the middle of the knee joint, with the impactor hitting both the femur and tibia at the patella for all the three models. Simulation results were analyzed to evaluate the loading characteristics at the femur, tibia, knee, and ligaments across the 3 models. These characteristics include the peak force, absorbed energy, and peak stress. KTH loading characteristics were then evaluated for trends between the 3 different models at varying impact velocities. Results: The results of the simulations demonstrate that the child knee joint’s response to impact forces varied significantly based on the impact velocity and the age of the child model. The force-displacement diagrams provided valuable insights into how the child knee joint reacts under different impact velocities, showcasing a clear trend of increased force with higher impact velocities. These diagrams also highlighted that the child knee joint’s ability to absorb impact energy decreased with higher impact speeds which is critical for understanding injury mechanisms in real-world crash impact scenarios. The variations in force-displacement characteristics, energy absorption, and stress distributions across the three child models underscores the importance of accounting for age when evaluating knee crash impact injury risks in children. Significant contributions: This is the first study to evaluate the effects of age and impact velocity on pediatric KTH response. The findings of this study revealed that age-based intrinsic factors affect the impact response of the KTH complex in children. An understanding of child KTH crash impact injury mechanisms is important to reduce the burden of these injuries in children. Gap filled: The thesis demonstrates the importance of numerical simulations in evaluating pediatric knee joint biomechanical tolerance under crash impact conditions. The combination of various impact velocities, model age, and the analyses of key biomechanical variables provide a deeper understanding of how the child knee joint behaves under crash impact conditions thereby enhancing the assessment of KTH injuries sustained by children in vehicle crashes and their associated risk factors. These findings can be instrumental in improving vehicle safety standards and in designing vehicle crash protective systems for children.