
264
headform. The contact and boundary conditions work together to deform the straps
and to generate their internal stresses. In the final state of Stage I, LS-DYNA
software automatically exports coordinates and stresses of all nodes as the input of
Stage II.
Table I. Mechanical Properties of Headform Layers
Layer Density
(
3
g/m
)
Young’s Modulus
(M Pa)
Poisson’s Ratio
Stage II releases the FFR and allows the FFR to contact the headform. We also
constrain the displacements of nodes on the back of the head and the bone layers of
the forehead, ...