DELRHO 
ALAMB 
ZETAV 
AKV(1) 
AKV(2) 
AMU 
FMOVIE 


13 
Card: Field 
Variable 

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


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 intervehicle 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 
ζ_{v} 
The minimum relative velocity for full intervehicle 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 intervehicle 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) 
K_{v1} 
Loaddeflection characteristic of V1 (see explanation after card 13). Values range from around 40 to around 90. 
lb/inch^{2} 
N/cm^{2} 
13:6 
AKV(2) 
K_{v2} 
Same as above, but for V2. 


13:7 
AMU 
μ_{v} 
Intervehicle 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 ζ_{V}). The force tangent to the interface opposing the relative motion = μ_{v} 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). 


13:8 
FMOVIE 

If >=0, write time history of damage display (for graphics program). To omit , set < 0. 


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