
202 Forensic Engineering Fundamentals
e maximum values of the normal and shearing stresses are given by
στ
maxmax
F
F
(7.28)
Note that the normal stress is either a maximum or minimum on planes where the
shearing stress is zero. Shearing and normal stresses under axial loading will fail in
tension on the transverse plane for brittle materials. In contrast ductile materials loaded
in tension will fail in shear on the 45° plane. For calculations of bone fractures, it is
sucient to calculate the forces that break the bone assuming the maximum stresses.
en, some variability analysis can be introduced to take care of any uncertainties in
the c ...