Transcript The Riera Curve March,25 2006 Ingo Brachmann

The Riera Curve
Ingo Brachmann
March,25th 2006
Outline

Approach and Iterative Algorithm

Example: F4 Aircraft Impact

Advantages

Boeing 767 – Riera Curve
Riera Approach (1968)
Rigid
Zone
Mxa = mv
Rigid
Target
Ma  m v
Rigid
Zone
Deformation
Zone
Mxb = (m-dm)(v-dv)
Mx,dm =
dm×vr
Fx
Rigid
Target
M b  m  dmv  dv  dm  v r 
m  dv v  v r   dm
F

dt
dt
F  Pc    v
2
Riera Iterative Algorithm
ti 1  ti  t
xi 1  xi  vi t
mi 1  mi  i vi t
Assumptions
vi 1  vi  v
t
v   Pci 
mi
Fi 1  Pci1   v
2
i 1 i 1
Pci   y  Ai
F4 Aircraft Impact (Test Set-Up)
Target
Phantom F4 aircraft
17.74m
MassF4
MassFuel
East
West
7.0m
7.0m
vimpact=
215 m/sec
= 14.2 t
= 4.8 t
MassImpact = 19.0 t
MassTarget = 469.0 t
Test Procedure
Mass-Distribution - F4 Aircraft
4000
F4+Fluid (Test)
Fluid (Test)
Mass per Unit Length (kg/m)
3500
F4+Fluid (Simulation)
3000
Fluid (Simulation)
2500
2000
1500
1000
500
0
0
2
4
6
8
10
12
Distance (m)
14
16
18
20
Crushing Force Pc - F4 Aircraft
100
90
Test Data (F4-Aircraft)
80
50% Py
Pc (MN)
70
60
50
40
30
20
10
0
0
2
4
6
8
10
12
Distance (m)
14
16
18
20
Impact Velocity - F4 Aircraft
Impact Velocity (m/sec)
220
200
Test Data (F4-Aircraft)
180
Riera Curve
160
140
120
100
80
60
40
20
0
0
10
20
30
40
50
60
Time (msec)
70
80
90
100
Riera Curve – F4 Aircraft Impact
200
Test Data (F4-Aircraft)
180
Riera Curve
Impact Force (MN)
160
140
120
100
80
60
40
20
0
0
10
20
30
40
50
60
Time (msec)
70
80
90
100
Advantages of Riera Approach
Estimation of

Mass Distribution () vs. Crushing Force (Pc)

Velocity and Force Distribution during Impact

Impact Damage w/o detailed aircraft model
Aircraft Model Reduction using Riera Curve
Riera Curve – Boeing 767
200
Riera Curve (Upper Bound)
180
Riera Curve (Lower Bound)
Impact Force (MN)
160
140
120
100
80
60
40
20
0
0
50
100
150
200
250
300
Time (msec)
350
400
450
500
Questions
?…