A numerical study on the safety belt-to-pelvis interaction

Area of Science:

• Biomechanics
• Vehicle Safety
• Injury Biomechanics

Background:

• Lap belt submarining over the iliac crest during frontal crashes elevates occupant injury risk.
• Numerous occupant and belt design factors contribute to this phenomenon.

Purpose of the Study:

• Investigate safety belt-to-pelvis interaction during frontal crashes.
• Identify key parameters influencing lap belt submarining.
• Explore the impact of initial lap belt position on this interaction.

Main Methods:

• Developed a finite element model simulating lap belt interaction with the pelvis via soft tissue.
• Analyzed belt design parameters (angle, force, loading rate, friction) and occupant parameters (pelvis angle, soft tissue properties, friction).
• Varied subcutaneous adipose tissue thickness to assess initial lap belt position effects.

Main Results:

• Identified influential parameters: belt angle and force (design), pelvis angle and soft tissue compressibility (occupant).
• Higher risk of lap belt slide observed with superior initial lap belt positions.
• Lap belt angle emerged as the most critical submarining parameter.
• Subcutaneous adipose tissue thickness impacts lap belt-to-pelvis interaction, increasing risk for obese occupants.

Conclusions:

• Lap belt angle, belt force, pelvis angle, and soft tissue compressibility significantly influence submarining risk.
• Initial superior lap belt positioning increases the likelihood of belt slide over the iliac crest.
• Obesity, indicated by thicker adipose tissue, elevates the risk of lap belt submarining and associated injuries.