Computational pregnant occupant model, ‘Expecting’, for crash simulations

• Published in: Proceedings of the Institution of Mechanical Engineers. Part D, Journal of automobile engineering Vol. 223; no. 7; pp. 891 - 902
• Main Authors: Serpil Acar, B, van Lopik, D
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.07.2009; Sage Publications; SAGE PUBLICATIONS, INC
• Subjects: Acceleration; Air bags; Anthropometry; Applied sciences; Automobile safety; Biological and medical sciences; Biomechanics. Biorheology; Computer simulation; Dynamic response; Exact sciences and technology; Fetuses; Finite element method; Fundamental and applied biological sciences. Psychology; Fundamental areas of phenomenology (including applications); Ground, air and sea transportation, marine construction; Injuries; Load distribution (forces); Mathematical analysis; Mathematical models; Physics; Placenta; Pregnancy; Road transportation and traffic; Seat belts; Simulation; Solid mechanics; Steering; Stress concentration; Stress distribution; Structural and continuum mechanics; Tissues, organs and organisms biophysics; Traffic accidents & safety; Uterus; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); seat belt; safety; injury; modelling; airbag; fetus; crash; pregnant; Motor car; Anthropometry; N body system; Modeling; Finite element method; Steering wheel; Safety; Human; Dynamic response; Stress analysis; Vibration; Traffic accident; Safety belt; Air bag; Biomechanics; Pregnancy; Vehicle direction; Crush; Mechanical shock
• ISSN: 0954-4070; 2041-2991
• DOI: 10.1243/09544070JAUTO1072

Abstract A computational model of the pregnant occupant, which is capable of simulating the dynamic response to acceleration impacts, is introduced. The occupant model represents a 5th percentile female at around the 38th week of pregnancy. A finite element uterus and multi-body fetus is integrated into an existing female model to incorporate pregnant female anthropometry. The complete model, ‘Expecting’, is used to simulate a range of frontal impacts of increasing severity from 15km/h to 45km/h. Three levels of occupant restraint, completely unrestrained, three-point seat belt, and three-point seat belt with an airbag, are investigated. The strains developed in the uterus because of loading from the seat belt and steering-wheel unit are presented, together with an analysis of stress distribution due to inertial loading of the fetus on the uterus. The unrestrained cases are shown to be the most dangerous to the fetus, owing to the large interaction with the vehicle steering wheel at the level of the placenta. The use of a three-point seat belt together with a driver airbag appears to offer the greatest protection to the fetus.