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ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

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Part<br />

Material<br />

property<br />

Face Elastic<br />

Cortical skull<br />

Trabecular skull<br />

Elastic Plastic<br />

Brittle<br />

Elastic Plastic<br />

Brittle<br />

Skin Elastic<br />

Brain,<br />

cerebellum and<br />

brain stem<br />

Brain/skull<br />

interface<br />

Falx and<br />

tentorium of the<br />

brain<br />

Viscous Elastic<br />

Elastic<br />

Elastic<br />

Material<br />

parameter<br />

Value<br />

Density 2,500 kg.m -3<br />

Young modulus 5.0E+03 MPa<br />

Poisson’s ratio 0.23<br />

Density 1,900 kg.m -3<br />

Young modulus 1.5E+04 MPa<br />

Poisson’s ratio 0.21<br />

Bulk modulus 6.2E+03 MPa<br />

UTS 90.0 MPa<br />

UCS 145 MPa<br />

Density 1,500 kg.m -3<br />

Young modulus 4.6E+03 MPa<br />

Poisson’s ratio 0.05<br />

Bulk modulus 2.3E+03 MPa<br />

UTS 35.0 MPa<br />

UCS 28.0 MPa<br />

Density 1.0E+03 kg.m -3<br />

Young modulus 1.67E+01 MPa<br />

Poisson’s ratio 0.42<br />

Density 1,040 kg.m -3<br />

Bulk modulus 1.125E+03 MPa<br />

Short shear modulus 4.9E-02 MPa<br />

Long shear modulus 1.62E-02 MPa<br />

Decay constant 145 s -1<br />

Density 1,040 kg.m -3<br />

Young modulus 0.12E-01 MPa<br />

Poisson’s ratio 0.49<br />

Density 1,140 kg.m -3<br />

Young modulus 3.15E+01 MPa<br />

Poisson’s ratio 0.45<br />

Element<br />

type<br />

Shell<br />

thickness<br />

[mm]<br />

Shell 10.0<br />

Shell 2.0<br />

Shell 3.0<br />

Solid /<br />

Solid /<br />

Solid /<br />

Shell 1.0<br />

Table 1: Mesh and mechanical behaviour characteristics of the SUFEHM.<br />

3.2 Human head injury mechanisms and tolerance limits<br />

As described by [5] and illustrated in Table 2, four injury criteria are computed with this<br />

model.<br />

Injury type Proposed injury criterion 50% risk<br />

Skull fracture<br />

Global strain energy of the<br />

skull [mJ]<br />

833 mJ<br />

Subdural haematoma<br />

Global strain energy of the<br />

brain/skull interface [mJ]<br />

4211 mJ<br />

Moderate neurological injury<br />

Brain, cerebellum and brain<br />

stem Von Mises stress [kPa]<br />

27 kPa<br />

Severe neurological injury<br />

Brain, cerebellum and brain<br />

stem Von Mises stress [kPa]<br />

39 kPa<br />

Table 2: Human head injury mechanisms and tolerance limits for four kind of traumatic<br />

head injuries.<br />

3.3 Human head impact reconstructions<br />

The experimental cadaver heads impacts have been achieved by the same way for each<br />

case. A double pendulum has been built with different impactor masses for each case

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