Modeling viscoelastic responses of the head/neck system during pilot ejection

The effect of added head mass during pilot ejection from an aircraft is currently being studied at the Wright Patterson Air Force Base in Ohio. The Articulated Total Body model, a FORTRAN computer program capable of simulating three-dimensional human body motion using rigid body dynamics, has been chosen to simulate the response of the head and neck to an ejection-like acceleration. The present Viscoelastic configuration of the head/neck model, which is capable of head rotation and axial neck deformation, was validated with experimental head acceleration data from live human volunteers subjected to a 10G_Z deceleration in the Vertical Deceleration Tower at Wright Patterson Air Force Base. Experimental head z-direction acceleration data from a first subject, L7, was reproduced accurately using the ATB model. However, Simulated head z-direction acceleration profiles for a second subject, B9, could not match experimental data for this subject, even after numerous variations of parameters controlling the head/neck response of the ATB model. Two of these parameters were determined to be time-varying for subject B9, and regression equations were developed describing the parameters as functions of time. Because the current ATB program does not allow time-varying parameters, the program code was modified to include two new subroutines in which the values of the parameters are calculated with each time increment. Modifications to the ATB model resulted in an improved simulated head z-direction acceleration profile for subject B9 when compared with previous simulations using constant value parameters.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Engineering Mechanics

Department dc:contributor.department

Engineering Mechanics

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1994

Author dc:creator

• Deuel, Christopher R.

Chair dc:contributor.committeechair

• Schneck, Daniel J.

Committee members dc:contributor.committeemember

• Henneke, Edmund G. II
• Grant, John Wallace

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-12042009-020255

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/46109