SMAC Compatibility Options - (Card 90) (cont.)













Card:  Field




Original Units

Metric Units




The Collision routine has undergone several refinements since the original release of SMAC by Calspan and McHenry Software, Inc.. Some improvements are the ability to use 1 degree increments in the radial vector scan, an increase in the number of iterations possible to find equilibrium, and refinement of the restitution logic.

If =0, use default m-smac Collision routine per m-smac.

If =1, use original SMAC Collision routine per EDSMAC.

If >1, as a part of continuing ongoing research by McHenry Software, Inc. we are in the process of Collision routine refinements. This option will be used to test the refinements.






In some of the published SAE papers by the authors of EDSMAC, they have included descriptions of changes to the Collision routine. One description included  changes which appear to permit collision sweep scans >180 degrees. This change is the CollPSf change. If you wish to mimic the EDSMAC program, and/or determine the effects of the changes, then set this option to 1.0

If =0, use m-smac & Calpan CollPSf logic.

If =1, use EDSMAC modified CollPSF logic.






In some of the published SAE papers by the authors of EDSMAC, they have included descriptions of changes to the DAMAGE routine logic in an attempt to avoid occasional post-processing logic failures which do not match the clock directions and delta-V outputs. The change as specified in the SAE paper we call the Damage modification.

If =0, use m-smac & Calpan post-processing Damage logic.

If =1, use EDSMAC modified post-processing Damage logic.






Refinements were made to the logic associated with the testing for side-slap impacts in the Main routine.

= 0.0, use normal m-smac refinements to scan for sideslaps

= 1.0, use the logic of the original NHTSA smac/EDSMAC program (caution: the original NHTSA smac logic may produce lesser side-slaps than actual and/or miss a sideslap impact dependent on the DTTRAJ and DTCOLT time increment sizes chosen)

If =2, Scan for 0.25 seconds after initial separation instead of 100 time increments. This logic is per SAE paper "SMAC-97", 97-0947

If you are so inclined, you can also optionally set and test different durations of the scan time and/or the number of steps on card 91, fields 6, 7.






If set = 1.0, Option turns off the friction zone mirror image characteristic. The  friction zone will only be effective in the quadrant(s) defined by the endpoints. The original SMAC contains logic which creates a mirror image of friction zone line defined on card 12. EDSMAC changed the option to turn off the mirror image.







Set this option =1.0 to set all the options for m-smac to best match the EDSMAC program. Results produced with this option should match those produced with the EDSMAC program. Please notify MSI if you find any differences (Please see McHenry Software Error Reporting Procedures for further information).

Setting this option to 1.0 has the same effect as setting card 90 fields 1 through 8 =1.0 and card 91 field 1 = 1.0 (minor drag conversion anomaly in EDSMAC)






Card 91 - SMAC Compatibility Options