DELRHO |
ALAMB |
ZETAV |
AKV(1) |
AKV(2) |
AMU |
FMOVIE |
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13 |
Card: Field |
Variable |
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Description |
Original Units |
Metric Units |
13:1 |
DELPS0 |
∆ψ |
The interval between radial vectors. The SMAC program calculates all collision forces in a clockwise sweep about the center of gravity of V1. The sweep is broken into increments (360/ DELPSO must be an integer). Too large a value of DELPSO will cause inaccuracies; too small a value will exceed the program's capacity. The collision interface is handled in a table of up to 200 points. If more than 200 points are required to handle the damage area, the message "ISTOP=9" appears on the printout. The suggested value is 1 degree, which can be increased (e.g. to 2 or 3) if the error message "ISTOP=9" appears. |
degrees
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13:2 |
DELRHO |
∆ρ |
The increment of change of the radius vector. (See explanation after card 13.) A value of around 0.1 is recommended. |
inches |
cm |
13:3 |
ALAMB |
λ |
The acceptable error in inter-vehicle pressure equilibrium. Choose λ greater than Kv1 times ∆ρ and also greater than Kv2 times ∆ρ (see explanation after card 13). e.g. for Kv1 = 30.0, Kv2 = 50., and ∆ρ= 0.2, then λ could be 12. |
lb./inch |
N/cm |
13:4 |
ZETAV |
ζv |
The minimum relative velocity for full inter-vehicle friction. If, while in contact, the adjacent surfaces of the two vehicles move with respect to each other at a speed less than this, the effective inter-vehicle friction increases, starting from zero, as a linear function of the relative velocity and it reaches the full value at ZETAV A value of around 5.-20. Is recommended. Note for higher values of AMU (field 7) use of lower zetaV values may produce rapid fluctuations in the direction of the resultant accelerations (“chatter”). |
in/sec |
cm/s |
13:5 |
AKV(1) |
Kv1 |
Load-deflection characteristic of V1 (see explanation after card 13). Values range from around 40 to around 90. |
lb/inch2 |
N/cm2 |
13:6 |
AKV(2) |
Kv2 |
Same as above, but for V2. |
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13:7 |
AMU |
μv |
Inter-vehicle friction coefficient: This is the coefficient of friction between the two vehicles when they are in contact and the adjacent surfaces of V1 and V2 are moving with respect to each other (at a velocity greater than ζV). The force tangent to the interface opposing the relative motion = μv times the force with which the surfaces are pressed together. A value of about 0.55 is recommended (The maximum range of this input should be from 0.0 to 1.0). |
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13:8 |
FMOVIE |
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If >=0, write time history of damage display (for graphics program). To omit , set < 0. |
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