Card 16 - Impulsive Constraint "Snag" Veh1, Veh2
Optional impulsive constraints that resist the relative motions of the two vehicles during a portion of the collision contact. In many impacts, the two colliding vehicles may momentarily interlock, independent of the magnitude of the compressive collision forces and therefore their behavior is not adequately modeled with simple inter-vehicle friction. This option has been added to permit the modeling of an impulsive constraint on the relative motion. (Input cards 16, 18.)
Inputs for a "Snag" Impulsive Restraint are entered on Cards 16, 18, and 19.
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TSWIND |
FSOPO |
XSPI |
YSPI |
AKSP |
DELSPM |
Qembed |
AKSP2 |
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16 |
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Card: Field |
Variable |
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Description |
Original Units |
Metric Units | ||||||||||||
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16:1 |
TSBEG |
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"SNAG" Impulsive Restraint Optional Input For SNAG, you specify a point in either V1 (FSOPO=1,2) or V2 (FSOPO=11,12) and at the start time for the snag (TSBEG) the location of the point specified is determined either in the other vehicle (FSOPO=2,12) or in space (FSOPO=1,11). Then an impulsive constraint is applied to the vehicle(s), based on the stiffness AKST, to attempt to minimize the separation of the points during the pusle width (TSWIND). See DISCUSSION Snag Option
Time to begin reaction and to begin use of DTCOLL. NOTE: adding 100 to FSOPO (field 3 below) will make the TSBEG relative to the impact time. |
Sec |
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16:2 |
TSWIND |
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Pulse width, or duration of reaction. |
Sec |
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16:3 |
FSOPO |
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Option = 0 - no reaction. 1 - Point specified in V1, reaction point fixed in space. 101 same as Opt 1 except TSBEG relative to impact 2 - Point specified in V1, reaction point fixed in V2. 102 same as Opt 2 except TSBEG relative to impact 5 - Point specified in V1, Pole reaction. (If Pole chosen, then must include card 19) 11 - Point specified in V2, reaction point fixed in space. 111 same as Opt 11 except TSBEG relative to impact 12 - Point specified in V2, reaction point fixed in V1. 112 same as Opt 12 except TSBEG relative to impact |
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16:4
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XSPI |
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X coordinate of force application point in either V1 (FSOPO=1 or 2), in V2 (FSOPO=11,12) or for Pole option (FSOPO=5) the space fixed location X location of the pole center. |
inches |
mm | ||||||||||||
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16:5 |
YSPI |
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Y coordinate of force application point in either V1 (FSOPO=1 or 2), in V2 (FSOPO=11,12) or for Pole option (FSOPO=5) the space fixed location X location of the pole center. |
inches |
mm | ||||||||||||
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16:6 |
AKSP |
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Linear load-deflection characteristic of impulsive force. (Only for FSOPO not equal to 5.) |
lb/inch |
N/cm | ||||||||||||
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16:7 |
DELSPM |
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Deflection at which saturation of impulsive force occurs. NOTE: Maximum value of Impulse = AKSP*DELPSM*TSWIND |
inches
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Mm | ||||||||||||
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16:8 |
Qembed |
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For use with Pole Option: Embedment distance. |
inches
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Mm | ||||||||||||
Card 16, Seq 1 - Impulsive Restraint "Snag" -
Veh3