
297Accident Reconstruction
e deection end slope is then
ϕ=
FY
2
(9.217)
e shear stress is
f
F
v
=
(9.218)
e maximum moment is
(9.219)
e actual bending stress is then given by
f
M
b
=
(9.220)
For oak, the bending strength F
b
is 800 psi, the shear strength F
v
is 85 psi, and the modulus
of elasticity is 900,000 psi. If f
v
is greater than F
v
, yield due to shear stress occurs. If f
b
is
greater than F
b
, yield due to bending stress occurs.
Introduction to Momentum Methods
Probably the most powerful technique used in accident reconstruction is that of the con-
servation of momentum. Momentum may also be the most underused technique because
of its subtlet ...