Average Head Circumference: 60 cm Expected

Impact Force: 3000 N (from potential blunt trauma)

Safety Factor: 2 (for higher protection).

To calculate the required shell thickness, we'll use a simplified version of the formula:

t = (F * r) / (σ * L)

Where:

t = shell thickness (cm),

F = impact force (N)

r = head radius (cm),

σ = allowable material stress (MPa)

L = helmet length (cm)

Assuming:

r = 30 cm , σ = 250 MPa , L = 28 cm

Plugging in the values: