Biomedical Engineering Reference
In-Depth Information
The worst-to-best ratio of Eq. (3.184) for the forces transmitted to the
dummy is
10
.
2
7
.
6
=
R
=
1
.
34
.
(3.202)
This reasonably low value would probably be acceptable in practice.
3.6.3
Rational Design of Sled Test Standards
In the previous section, the application of the extremal disturbance analysis
to check the sensitivity of the response measure (the force transmitted to the
occupant) to the variation of the sled deceleration pulse within a prescribed
corridor was discussed. This concept suggests a technique for the rational
design of such a corridor so that the worst-to-best ratio does not exceed
an allowed value. An example would be a corridor in the shape of the
trapezoid
ABCD
shown in Fig. 3.17. A generic trapezoid can be represented
analytically by the piecewise linear function
⎧
⎨
0
,
t
∈
(
−∞
,τ
1
)
∩
[0
,
∞
),
a(t
−
τ
1
)
,
t
∈
(τ
1
,τ
1
+
τ
2
)
∩
[0
,
∞
),
τ
2
ψ(t)
=
(3.203)
a,
t
∈
(τ
1
+
τ
2
,τ
1
+
τ
3
)
∩
[0
,
∞
),
⎩
a(t
−
τ
1
−
τ
4
)
,t
∈
(τ
1
+
τ
3
,τ
1
+
τ
4
)
∩
[0
,
∞
),
τ
3
−
τ
4
0
,
t
≥
τ
1
+
τ
4
.
B
C
a
A
D
+
+
+
Time
FIGURE 3.17
Trapezoidal bound for the force applied to the object by the shock iso-
lator.
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