SMAC Frequently Asked Questions


The acronym SMAC stands for the Simulation Model of Automobile Collisions. The computer program is a time-forward simulation model. With SMAC you set up a mathematical "full scale crash test" using the vehicle weights, dimensions and other properties, you set the initial positions, headings and velocities and start the simulation run. The vehicles collide and run out to rest. You then compare the SMAC predicted positions, orientations at rest and predicted damage with the accident evidence.

SMAC was initially developed for government sponsored research in highway safety. It is currently being used mainly with respect to litigation. Whatever the use of SMAC, or its equivalent, limitations on accuracy and generality that were imposed by early 1970ís vintage mainframe computers should not persist.


SMAC features comparison table*

 

m-smac msmac3D HVE-2DSMAC HVE-3DSMAC
Vendor McHenry Software McHenry Software Engineering Dynamics Engineering Dynamics

Approximate Cost?

$2000 $5000-$7500 $2000+ $10,000+

Multiple license discount?

yes TBD yes ??

Approx cost for extra license?

$650-$1000 TBD ?? ??

Annual Fee?

$250-$500 ~$1000 ~$800+ ~$2000-$4000+

Support Options

       

Phone support?

yes yes ??** ??**

email support?

yes yes ?? ??

response time?

0-3 hrs 0-3 hrs ??** ??**

knowledgeable responses?

yes yes ??** ??**

Updates in response to requests for enhancements?

Yes Yes no no
Informative website? yes yes no no
Licensee only website with Q&A & news? yes yes no no
Updates posted to web? yes yes no no

Frequency of enhancements?

very very no no

Platform?

Win32/64,Win7 Win32/64,Win7 Win16? Win16?
Enhancements beyond original SMAC? yes yes minor minor
2 Dimensional (2D) or 3 Dimensional (3D)? 2D 3D 2D 3D

Max # Vehicles

3, (4 coming) 3, (4 coming) 2 3+

polygon friction zones

yes yes yes yes

vehicle databases included?

yes yes extra extra

optional individual tire friction?

yes yes no yes

Output time histories?

yes yes with effort with effort

impulsive constraint 'snag'***

yes yes no no

CCI option***

yes yes no no

Steer Degree of Freedom?***

yes yes no yes

tire blowout ability?

yes yes no yes

barrier option?

yes yes no no

output in format for spreadsheet programs?

yes yes no no

acceleration monitor at any location?

yes yes no yes

measured damage targets display?

yes yes no no

POI/POR targets display?

yes yes no no

4 wheel steering?

yes yes no ??

driver model/path follower?

yes yes no yes

animation

robust robust yes yes

animation autopan/autozoom?

yes yes no no

DXF/CAD support?

yes yes yes yes

tabular display option?

yes yes no no

bitmap underlays?

yes yes no no

options vehicle-fixed display?

yes yes no ??

simplified occupant kinematics model?

yes yes no no

Articulated vehicle option?

yes soon no yes

trailer collision model?

yes soon no no

trailer release option?

yes soon no no

Please send any corrections/additions for this Comparison Table to webmaster@mchenrysoftware.com

*Note1: We have not included PC-CRASH in this comparison. PC-CRASH is a momentum based, instantaneous exchange of momentum program. It does not have the sophistication of the SMAC collision model which can lead to very serious problems and sensitivities for some impact configurations.

**Note2: This rating for technical support for EDC HVE is based on discussions with many current and/or former EDC HVE users who classify the response as slow and incomplete.

***Note3: For definitions of some of the terms the reader should review the paper SMAC-97. ('snag'=impulsive constraint, see pp71-73), CCI=Center of Collision Interface, see pp67-70, etc.)  Note many of the items listed under OPTIONS are important enhancements which should be implemented in all versions of SMAC.

What is the difference between m-smac and the other versions of SMAC?

Raymond R. McHenry was the principal investigator and analytical developer for SMAC (as well as CAL2D, HVOSM & CRASH!). For over 22 years he and Brian G. McHenry have worked together as McHenry Consultants. Performing research and development on the various software programs as well as consulting on thousands of individual case reconstructions. As inventors of SMAC and as users of SMAC on a daily basis to reconstruct accidents, the McHenrys have created a refined and enhanced version of SMAC. Due to repeated requests from interested parties for a McHenry version of SMAC they formed McHenry Software in 1994.

Papers "SMAC-87",[McHenry, B.G. and McHenry, R. R., SAE Paper 88-0227, 1988 SAE Transactions]  and "SMAC-97 - Refinement of the Collision Algorithm"  [McHenry, B.G., McHenry, R.R., SAE Paper No. 97-0947, 1997 SAE Transactions] contain documentation of needed extensions and refinements of SMAC. SMAC was created in the 1970's on mainframe computers and in the 1980's moved to mini-computers and then in the 1990's to PCs, and many of the initial limitations and simplifying assumptions of SMAC must be revisited and refined. Please review SAE papers SMAC-87 and SMAC-97 for a detailed discussion and presentation.

The other vendors of SMAC (Engineering Dynamics (EDSMAC, HVE SMAC) and ARsoftware (WinSMAC) have not made any significant changes or improvements to the SMAC program. They merely sell the original SMAC program with a Windows wrapper.

Please see our discussion on the various versions of SMAC and our  m-smac page for a list of some of the extensions and refinements of the SMAC program in m-smac.

What is your initial license fee?

Please see our McHenry SMAC Pricing Information page.

Do you charge a fee each year for maintenance/renewal?

Software for accident reconstruction requires continual review, update and enhancements. And all users should use the latest to insure that they have all the tools available. Therefore we require an annual fee to support our continued research and development of the software. Our $500 renewal fee(for 2D) and $1000 for 3D is reinvested in development and tech support. We maintain and update a website and respond in a very timely manner to users questions, problems and requests for enhancements/additions/etc. Also, we also offer a 'quick pay' discount for renewals of 20%. So the actual cost is $400 2D/$800 3D for prompt and knowledgeable support. Please see the Order form for more information. 

Have there been erroneous and misleading statements published about SMAC?

Over the years, several papers have taken cheap shots at SMAC (some funded by automobile manufacturers, and some as thinly veiled sales pitches for other software). As a service to SMAC users we offer a page with explanations of the erroneous and misleading statements about SMAC and CRASH.  


Please also read:


Please revisit soon for additional notes and information.


If you have any questions or feedback we can be reached by e-mail at McHenry@mchenrysoftware.com