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Raymond R McHenry Pioneering Accomplishments
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Welcome to McHenry Software Inc
Why consider msmac3D

Site Map of old pages (as on August 28, 2017)

The WWW homepage of McHenry Software, Inc.
Licensee site launch area of Mchenry Software
A General Introduction to Accident Investigation and Reconstruction
A Review of the CRASH Damage analysis and the NHTSA reformulation
3-D or NOT 3-D, THAT is the Question!
McHenry Publications sorted by Decade
McHenry SAE TOPTEC on SMAC
Brian McHenry Presentation at 2001 SeCCC
Brian McHenry ATB Users’ Conference Presentations
McHenry Software m-smac program
McHenry Software News!
Ordering information for NHTSA crash and specs databases
Links to other Collision Reconsturction Related Sites
Contact information for McHenry Software, Inc.
2012%20McHenry%20Short%20History%20scanned.pdf
Automatic Iteration of SMAC – SMACITER
m-smac: McHenry Software SMAC program
McHenry Software DEMOS
How to order McHenry Software m-edit/m-smac programs
SAE 2003 Conference
McHenry Accident Reconstruction Book Order form
m-crash: McHenry Software CRASH program
Background Infromation on Accident Reconstruction
Traveling Speed and the Risk of Crash Involvement
McHenry Software m-hvosm program
Crash Victim Simulator
Links to other Collision Reconsturction Related Sites
References cited in the WWW site of McHenry Software, Inc.
rTransport Canada Canadian Specification Database
McHenry Software m-hvosm program
Raymond R. McHenry Resume
Sprial Jump Automobile Stunt Patent by Raymond R. McHenry
A General Introduction to Collision Investigation and Reconstruction
McHenry Software Collision and Simulation Software
Link to Licensee Site for McHenry Software
A Review of the CRASH Damage analysis and the NHTSA reformulation
3-D or NOT 3-D, THAT is the Question!
2003 SAE
McHenry Technical Reports Sorted by Year
McHenry SAE TOPTEC on SMAC
The Algorithms of CRASH by Brian McHenry
Occupant Kinematics in Forensics: ATB
McHenry Software m-smac program
McHenry Software News!
Ordering information for NHTSA crash and specs databases
Contact Information for McHenry Software, Inc.
SMACITER
SMAC Frequently asked Questions
demos – McHenry Software Demos
How to Order McHenry Software m-edit/m-smac
McHenry%20Accident%20Reconstruction.pdf
m-crash: McHenry Software CRASH Accident Reconstruction Program
SAE 2003 Conference
m-edit: McHenry Software m-edit program
CVS/ATB Occupant simulation program
crash3.pdf
McHenry Consultants
SMAC-type collision reconstruction programs
Other Versions of CRASH
McHenry Software, Inc. List of References
Ordering information for Transport Canada Canadian Specifications Database
SpiralJump.pdf
HVOSM87.pdf
McHenry_TRB.pdf
m-edit: McHenry Software m-edit program
rrm.pdf
RRM%20IME%20paper.pdf
McHenry%20750893.pdf
McHenry%20760776.pdf
McHenry%20861894.pdf
970960.pdf
970947.pdf
970949.pdf
970961.pdf
Sprial Jump Automobile Stunt Patent by Raymond R. McHenry
A General Introduction to Collision Investigation and Reconstruction
McHenry Papers published at the 1997 SAE Congress
McHenry Software Papers at the 1997 SAE Congress
A Review of the CRASH Damage analysis and the NHTSA reformulation
2003-01-0486.pdf
2003-01-0486%20Presentation.pdf
2002 SAE Accident Reconstruction Session Review Process
2001 SAE Accident Reconstruction Session Review Process
SAE Accident Reconstruction Session Review Process
McHenry Publications sorted by Subject
SECCC%20Presentation.pdf
McHenry SAE TOPTEC on SMAC Printer Friendly version
SMAC87.pdf
Rollover%20Potential%20of%20Vehicles.pdf
Calspan%20Rollover%20Study%20Executive%20Summary.pdf
HSRC%20safegeometric87.pdf
McHenry%20HVOSM%20Studies%20of%20Curb%20Impacts.pdf
Segal%20Hvosm%20Curb%20impacts.pdf
HVOSM%20parts%20of%20Leisch%20Curve%20Study.pdf
Leisch%20Curve%20Study.pdf
WorkZone%20Pavement%20Shoulder%20Dropoffs.pdf
Work%20Zone%20Considerations%20Pvmt%20Shoulder%20Dropoffs.pdf
HVOSM%20Studies%20of%20Highway%20Cross%20Slope.pdf
hvosm%20cross%20slope%20study.pdf
TRB%20923.pdf
Mchenry%20Task%20E%20Comparison%20of%20Simulatio%20n%20Models.pdf
HVOSM%20Studies%20of%20Cross-Slope%20Breaks.pdf
McHenry%20Analysis%20Spinout%20CRASH%201981.pdf
Revision_of_the_CRASH2_Computer_Program.pdf
CRASH_II_Users_Manual.pdf
McHenry%201975%20The%20CRASH%20Program.pdf
McHenry_730980.pdf
Math%20Recon%20Accidents%20Mchenry.pdf
HIC predictions with ATB
McHenry.pdf
HIC%20and%20the%20ATB.pdf
Occupant Kinematics in Forensics: Evaluating an ATB Application by Brian
G McHenry
J&J Technologies CVS/ATB Occupant Simulation model
2015_Order_Form.pdf
m-smac: Erroneous Statements about SMAC
Table 1 Summary of RICSAC tests
Table 2 Summary of m-crash reconstructions* of RICSAC tests:
McHenry SAE papers
J&J Technologies CVS/ATB Occupant Simulation model
McHenry%20Spiral%20Jump%20Patent%20US3814021.pdf
Text of SMAC-97 Presentation at 1997 SAE Congress
Questions/Answers related to SAE 97-0960
Questions/Answers related to SAE 97-0949
Authors’ Reply for McHenry SAE paper 97-0960
February 21, 2001 letter to Gustav Nystrum
Nystrom.pdf
March 18, 1997
970960%20Erroneous%20Reviewers%20Discussion.pdf
SAE Paper 97-0960 Appendix 3
McHenry Technical Reports Sorted by Subject
SMAC questions
2012%20McHenry%20Short%20History%20article.pdf
McHenry%20Response%20to%20Crash3%20paper.pdf
Explanation of errors in book by Watts on Low Speed Automobile Impacts
Hack job IPTM paper

medit32

default.htm
Medit32 by McHenry Software
Medit32 by McHenry Software
2010_Order_Form.pdf
Medit32 by McHenry Software
Medit32 by McHenry Software
Medit32 by McHenry Software
Medit32 by McHenry Software
Medit32 by McHenry Software
McHenry%20Software%20Training%202008.pdf
2012_Order_Form.pdf

msmac

MSMAC
MSMAC-toc.htm
_d2h_theme_nav_left_top.htm
_d2h_theme_nav_left_bottom.htm
Blank
m-smac Input Manual
Introduction
Analytical Approach: Collision Routine
Analytical Approach: Tire Forces
Extensions and refinements
Background
Notes on Input Instructions
Simulation Program control
Card 1 – Simulation Program control
Card 1, Seq 1 – Print Interval Change Option
Example – Print Interval Change
Initial Conditions
Card 2 – Initial Conditions – Veh1
Card 3 -Initial Conditions: Veh2
Dimensional and Inertial Properties
Card 4 – Dimensional and Inertial Properties: Veh1
Card 5 – Dimensional and Inertial Properties: Veh2
Tire Properties
Card 6 – Tire Properties: Veh1
Card 7 – Tire Properties: Veh2
DISCUSSION: Cornering Stiffness
Further Reading
Examples – Tire Cornering Stiffness Calculation
DISCUSSION: Moment of Inertia
Braking/Tractive Force Tables
Card 8 – Braking/Tractive Force Tables: Veh1
Card 9 – Braking/Tractive Force Tables: Veh2
Example: Braking/Tractive Force input tables
Example: Braking/Tractive Force input tables
Example: PCTOPT (% Force inputs option) inputs
Example: Variable increment (VARINC) inputs
Steer Tables
Card 10 – Steer Tables: Veh1
Card 11 – Steer Tables: Veh2
Terrain Friction Coefficients
Card 12 – Terrain Friction Coefficients
DISCUSSION: Friction decrement with speed
Collision Model, Crush Properties
Card 13 – Collision Model, Crush Properties
Card 14 – Coefficient of Restitution
Card 14, Seq 1 – Coefficient of Restitution – Veh2
DISCUSSION: Collision Model Inputs
Friction “Null Band”
Impulsive Constraint “Snag”
Card 16 – Impulsive Constraint “Snag” – Veh1, Veh2
Card 16, Seq 1 – Impulsive Restraint “Snag” – Veh3
Card 18 – Impulsive Restraint “Snag” Additional Options
Card 19 – Pole Impact Option
Example: Snag Option inputs
Example: Pole Impact inputs
DISCUSSION: Snag Option
Refinement in the Simulation of Structural Interactions During Collisions
DISCUSSION: Pole Impacts
Articulated Vehicle Option
Card 20 – Articulated Vehicle Option: Veh1
Card 22 – Articulated Vehicle Option: Veh1
Card 21 – Articulated Vehicle Option: Veh2
Card 23 – Articulated Vehicle Option: Veh2
Example: Tractor-trailer option inputs
DISCUSSION: Articulated Vehicle Option
TRACTOR MOMENT OF INERTIA
TRAILER MOMENT OF INERTIA
TRUCK/TRAILER TIRE PROPERTIES
DISCUSSION: Bus Properties
Dual & Tandem Tire Options
Card 24 – Dual & Tandem Tire Options
Steer Degree-of-Freedom
Card 25 – Steer Degree-of-Freedom: Veh1
Card 25, Seq 1 – Steer Degree-of-Freedom: Veh 1
Card 26 – Steer Degree-of-Freedom: Veh2
Card 26, Seq 1 – Steer Degree-of-Freedom: Veh 2
Example: Steer degree-of-freedom option inputs
Barrier Option
Card 27 – Barrier Option
Card 28 – Barrier Option
Card 29 – Barrier Option
Example: Barrier option inputs
Polygon Friction Zone Option
Card 30 – Polygon Friction Zone Option
Card 31 – Polygon Friction Zone Option
Card 32 – Polygon Friction Zone Option
Example: Polygon friction zone option
Cornering Stiffness Tables
Card 40 – Cornering Stiffness Tables: Veh1
Card 45 – Cornering Stiffness Tables: Veh2
TIRMU Tables
Card 44 – TIRMU Tables: Veh1
Card 49 – TIRMU Tables: Veh2
3rd Vehicle Option
Cards Required to Add a 3rd Vehicle in m-smac
Card 52 – Initial Conditions: Veh3
Card 54 – Dimensional and Inertial Properties: Veh3
Card 56 – Tire Properties – Veh3
Card 58 – Braking/Tractive Force Tables: Veh3
Card 60 – Steer Tables – Veh3
Card 98 – Secondary Collision Model – Veh1 Trailer or Veh3
Card 99 – Veh#3/Trailer Release Option
DISCUSSION: Damage Measurements
Damage Measurements, POI & POR Targets
Card 80 – Damage Measurements – Veh1
Card 85 – Damage Measurements – Veh2
Card 86 – Positions of Impact
Card 87 – Positions of Rest
SMAC/EDSMAC Compatibility Options
Card 90 – SMAC/EDSMAC Compatibility Options
SMAC Compatibility Options – (Card 90) (cont.)
Card 91 – SMAC Compatibility Options
DISCUSSION: Side-Slaps & Secondary Collisions
Impact Configuration SetIND Option
Card 92 – Impact Configuration SetIND Option
Card 93 – Outputs for CVS/ATB,Lightwave
Card 94 – Refined Collision Model Inputs
Refined Collision Model Inputs for Vehicle 1 – (Card 94)
Card 95 – Refined Collision Model Inputs for Veh2
Optional Center of Collision Interface (CCI)
Card 96 – Center of Collision Interface (CCI)
Gravitational Forces Simulation
Card 97 – Gravitational Forces Simulation
Driver Model/Path Following Option
Card 402 – Driver Model/Path Following
Card 403 – Driver Model Path-Generator Option
Card 404 – Driver Model Path-Generator Option
Card 405 – Driver Model Path-Generator Option
End of Input, Misc. Options
Card 9999 – End of Input, Misc. Options
DISCUSSION: Pedestrian and Occupant Trajectories
Pedestrian Impact Accident Investigations
Pedestrian Impact Accident Reconstruction
References
Appendix A:CRASH3 Table 8-1 (ref 28)
Appendix A:CRASH3 Table 8-2 (ref 28)
CONVERSION FACTORS
Error Codes

Reports

samplestockreportlandscape02.pdf
samplestockreportlandscape02
samplestockreportlandscape02.rtf
samplestockreportlandscape.pdf
samplestockreportlandscape
samplestockreportlandscape.rtf
sampleinputsreport.pdf
sampleinputsreport
sampleinputsreport.rtf
customerreportfromchartpresetwithmultichart.pdf
customerreportfromchartpresetwithmultichart
customerreportfromchartpresetwithmultichart.rtf

Forum

Proceedings2008_TOC.pdf
McHenry%20NATO%20Presentation.pdf

220801Nystrum_files

filelist.xml

Available with LEASE Pricing!

License for 3, 6 or 12 months, Affordable! Convenient!

See Pricing

FAQ (Technology, Licenses, Offers and others)

Read FAQ

2017 Jaguar Spiral Jump

Jaguar E-Pace Rollout includes McHenry Spiral Jump designed with msmac3D

Read more

Why consider msmac3D?

In Crash Reconstruction it is important to test and refine conclusions. msmac3D is that tool. Like running a mathematicl full scale test.

Please read more

1974 James Bond Spiral Jump

An auto stunt invented and designed by Raymond R. McHenry US Patent No. 3,814,021]

Read more

McHenry Software, Inc. (MSI) was formed in 1994 with the explicit intent to create, distribute and support accident reconstruction and vehicle simulation software. The McHenry’s have 90 years of cumulative experience and research on simulation and reconstruction

Thank you for your interest in McHenry Software, Inc.

We are social:

Contact Us:

McHenry Software®, m-edit, m-smac, m-crash, m-hvosm are trademarks of McHenry Software Inc. All rights reserved.

A SiteOrigin Theme

Realistic

We added the All New Animulation (Ani-mulation is our new word). You define the path as easy as Animation, with multiple segments as you intend, add the speed etc. and the program does the Simulation calculation and plots the simulated path keeping the Target Position as you define. This is not equivalent to Simulation, it is your path with Simulated terrain response. It is not simple terrain following, it is simulated terrain response.

And as you know, we are very strong in Simulation.

The principals at McHenry Software, Inc. (MSI), Raymond & Brian McHenry, have been active in the field of highway safety research for a combined period of over 90 years. In that time they have performed research for NHTSA, FHWA, NTSB, public and private research organizations and MSI internal development through which they have invented, developed and enhanced the state-of-the art of collision and rollover simulation programs and other reconstruction tools. The programs include CRASH, SMAC and HVOSM which are acronyms for accident simulation and collision reconstruction programs invented by Ray McHenry and on which Ray and Brian have extensively researched, developed and published. These programs form the foundation for many of the accident reconstruction and simulation tools in widespread use today.

Msmac3D is simulation, not animation, so the results correlate with reality. Please review our sample validation simulations and our recent paper “The Proper Use of Simulation Technology for Collision and Rollover Reconstructions and Highway Safety” for additional examples.

From our McHenry Forum topic: What is the difference between animation and simulation? We repeat the following to clarify the difference between animation and simulation:

Q: What is the difference between animation and simulation?
A: This is a frequently asked question particularly with the current capabilities of computers and animation. We cover the topic in 3D or Not 3D In accident reconstruction,

Animation is often used to illustrate an opinion. Animations generally use spline fit techniques to visually match movements of vehicles. Animation by itself does not test whether the movements and responses are physically possible, meaning whether or not they obey Newton’s Laws of Motion
Simulation is used in accident reconstruction to test and refine an opinion.
Simulations are mathematical models which attempt to apply and follow Newton’s laws of Motion.
Simulations can be used as the basis for an Animation meaning the mathematically simulated motion can be used in an animation to move the objects (for example, to move vehicles colliding, etc).

CAUTION: Simulations and Animations can also be used inappropriately!

The inputs should be fully revealed and checked. See 3D or Not 3D for a presentation of what you need to request when faced with a Simulation or Animation. For simulations you also need to verify if the model has been tested and validated and if the type of vehicle movement or collision interaction are consistent with the validations. All too often we find ‘experts’ misusing simulation models. For example see our discussion on the ATB simulation model and our discussion 3D or Not 3D for some related discussion on validation and simulation models.

Some additional information:

From the web Animation “is the rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement. It is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in a number of ways. The most common method of presenting animation is as a motion picture or video program, although several other forms of presenting animation also exist”.

From the web Simulation “is the imitation of some real thing, state of affairs, or process. The act of simulating something generally entails representing certain key characteristics or behaviors of a selected physical or abstract system. Simulation is used in many contexts, including the modeling of natural systems or human systems in order to gain insight into their functioning.[1] Other contexts include simulation of technology for performance optimization, safety engineering, testing, training and education. Simulation can be used to show the eventual real effects of alternative conditions and courses of action. Key issues in simulation include acquisition of valid source information about the relevant selection of key characteristics and behaviors, the use of simplifying approximations and assumptions within the simulation, and fidelity and validity of the simulation outcomes”.

We Belong to You

When you become a McHenry Software licensee you become our reason for bringing our technology direct to you: to serve you. We will work to make this product what you want. We will work to make our product exceed your expectations. We belong to you to provide you our accident reconstruction and simulation products to help you conveniently obtain an accurate accident reconstruction and simulation.

We appreciate your interest in McHenry Software and look forward to serving you.

Thank you for your support of McHenry Software.

We’ve said it on our websites more than once, we repeat it once again:

The principals at McHenry Software, Inc. (MSI), Raymond & Brian McHenry, have been active in the field of highway safety research for a combined period of over 90 years. In that time they have performed research for NHTSA, FHWA, NTSB, public and private research organizations and MSI internal development through which they have invented, developed and enhanced the state-of-the art of collision and rollover simulation programs and other reconstruction tools. The programs include CRASH, SMAC and HVOSM which are acronyms for accident simulation and collision reconstruction programs invented by Ray McHenry and on which Ray and Brian have extensively researched, developed and published. These programs form the foundation for many of the accident reconstruction and simulation tools in widespread use today.

Ray and Brian have devoted our professional lives working to create and improve accident reconstruction and simulation tools for highway safety and litigation purposes. We have created a user friendly, easily understandable and quickly presentable product. We plan to continually improve and extend the capabilities of the program for you, our McHenry Software licensee.

We can best improve our programs if we listen to you, our clients. Let us know what you like about the product, what you don’t like, any suggestions for improvement will be considered and prioritized.

Thank you for your interest in McHenry Software technology.

Testimonials

These are few of the comments and testimonials from our users:

“
So far, everything is work pretty good. I just opened the software and quickly explored some of the stuff. I love the vehicle database that you have. Anyway, I am enjoying the new additions and am thankful for how familiar it is to the 2D version.
”

“
I think this is great that you did these training videos and I hope you keep it up. It is especially helpful when you are jumping between softwares all the time like I am and you need to quickly recall how to use the software. I think its great tool for both newcomers and occasional users.
”

“
OK, I’ve watched about 6 or 7 videos up to an including the old 5-minute demo. They’re great: instructional, informative, succinct, and well thought out. Some of the sound is louder or quieter between them, but that’s honestly no big deal.Then I loaded/installed the program. All went well and basically installed itself (and kindly even discarded old/unneeded files; thank you.).

The projects I’ve tried so far work well and worked as shown in the videos. Changing views and tire tracks and other stuff I’ve tried so far works well.

Very good so far! Lots of work there! Looks and works well.

”

Free Trial Available

McHenry Software will be offering a free 2 week trial of the new msmac3D simulation and reconstruction program.

Simply fill out and send in the order form and request a free 2 week trial.

We won’t charge your credit card or cash your check. You will be provided a full working version for 2 weeks! At the end of two weeks you simply let us know what you like about the program, what you don’t like, and then whether you’d like to keep the program!

Also, we can arrange payment over time programs. Please let us know if you’d like to pay for the license over time and we will send you some options.

Value for Money

The pricing for msmac3D and msmac2D is contained in the Order Link at the top.

We believe you will find our pricing is value for your money. The principals at McHenry Software, Inc. (MSI), Raymond & Brian McHenry, have been active in the field of highway safety research for a combined period of over 90 years. We have been and will remain at the cutting edge forefront of accident reconstruction technology. With our development of the 3D graphical capabilities we now can directly provide to you our 3D simulation technology. Each and every enhancement and extension will be included in the automatic updates you will receive as a McHenry Software msmac3D licensee.

To summarize:

The 1st year for msmac3D will be somewhere between $5000 and $7000 (see the price list in the Order Link) which provided full 3D simulation technology and graphics capability. The msmac3D license also automatically includes msmac2D.
McHenry Software charges a reasonable annual license renewal fee to support our continued research and development of simulation, reconstruction and graphical components so ALL our users are using the latest version and we don’t waste time trying to support older versions. For each and every update, fix, enhancement, extension you as an msmac3D user will immediately get notified of an update to download and install.
- Our msmac3D/msmac2D combo annual renewal fee after the first year will be around $1000.
- For msmac2D only users the annual renewal will remain $500.
- Our renewals always include 20% discounts for quick pay.
- For a comparison, see what some others software vendors in the AR field charge for updates/renewals:
  - Engineering Dynamics (EDC) with their HVE) charge $2000-$6000 PER YEAR for their annual renewal and advertise 30+ year old McHenry enhancements and extensions)
  - PC-CRASH, which is a momentum based collision program, hide their renewal fee in annual updates that cost $750-$1000 (think about it, if you are using an older version in litigation against someone with a newer version, who will prevail? What will you HAVE to do? UPDATE of course! So why not simply call it an annual renewal fee?)

msmac3D and msmac2D will be the main two products we sell and market. No new or differently named product to make you buy something new.
Each and every update, enhancement and extension, both of the simulation and the graphics will be included in the active license fee.

McHenry Software will work to make msmac3D the complete product for all your accident and collision reconstruction needs.

Easy to use

Few hi-lights to show it is easy to use.

Simplification of the process of applying a 3D simulation & reconstruction
3D inputs automatically created based on 2D inputs: vehicle make, model, year, & content weight (occupants & cargo)
With automatically generated 3d vehicle inputs accuracy within ± 10%
More refined inputs can be specified however not required

See the Simulation being created in 3 Minutes

<br />

Automatic Iteration

AUTOMATIC ITERATION TO IMPROVE EVIDENCE MATCH AND SIMPLIFY THE MSMAC3D PROCESS

As any SMAC user is aware, many iterations of the SMAC program may be required to go from an initial approximation to an acceptable match of the measured trajectory and damage targets. Throughout the iterative process, the impact speeds and impact speed change results may not change significantly. Also, what constitutes an acceptable match can vary widely among users. Sometimes the focus is on a detailed match of the positions of rest; sometimes the focus is on a match of damage locations and extents on the vehicles. There is currently no standardized measure of the correlation of simulation results with the accident evidence.

Since the initial development of the SMAC program, there has existed a need to simplify the application process. The ultimate simplification would entail an automatic iteration procedure. Optimization techniques applied to the evidence match can serve to reduce the required time and effort and, also, can achieve greater uniformity of the evidence interpretation.

The working hypothesis of the automatic iteration of SMAC is that a unique set of impact conditions is required to achieve an acceptable match of all of the documented evidence (both damage and trajectory). The use of quantitative measures of the overall “fit” to the documented evidence and applications to experimental crash tests provided a means of proving the hypothesis, as well as demonstrating reconstruction accuracy and convergence rates. Note that successful efforts on automatic iteration in the msmac2D case were reported in Ref 13 (Fig 20 -23). That research proved the feasibility of an automated procedure for achieving a “best match” of measured evidence, starting with CRASH-type linear momentum/damage analysis initial approximations. Small deviations from a perfect “match” are, of course, imposed by the existing limitations of the SMAC computer program and by any inaccuracies in the reported evidence.

In the reported results the automatic iteration/optimization of msmac2D was demonstrated to successfully converge toward evidence matches in a variety of impact configurations. With measured evidence from full-scale tests on flat surfaces the automatic iteration procedure of msmac2D produced correlation of impact speeds and impact speed changes with deviations in individual results of less than approximately ± 10%.

The research confirmed that the initial approximation of the CRASH program, or any proper combination of linear momentum and damage analysis solution procedures, should provide an adequate initial approximation from which an automatic iterative/optimization procedure of msmac2D can be used to determine the impact speeds and impact speed changes within ± 10%.

For 3D simulations the only change required was to add automatic iteration/optimization of msmac3D results is to simply have the control algorithms use the msmac3D program instead of msmac2D program for iterating/optimizing towards a unique solution. The msmac3D automatic iteration/optimization program is currently in testing and will be included in the msmac3D release.

The msmac3D setup automatically generates all required 3D vehicle input definitions based on the vehicle make/model and any other supplemental information and the user can easily include 3D terrain information if applicable. Upcoming extensions of the automatic iteration/optimization routine will be to include comparisons with measured tire mark information and an extension to iterate/optimize on rollover and other single vehicle accidents.

Automatic Iteration solutions of a SMAC Reconstruction of a sample RICSAC Test.

Automatic Iteration Results with Crash Test results on Impact Velocity (first) and Impact Speed Change (second).

Comparison of msmac automatic iteration correlation factor “score” with maximum error.

Validated

An obstacle to detailed and scientific simulations in the past has been the complexity of highway vehicles (3D inertial properties, suspensions, tires, structural crush behavior) and the highway environment (geometrics, topography, obstacles). Proprietary extensions of mSMAC3D include routines that automatically generate default approximations for the required three-dimensional vehicle inputs (e.g., suspension & tire properties, roll and pitch moments of inertia) from the plane-motion 2D simulation inputs combined with the vehicle make, model and loading. These initial input approximations combined with the ability to overwrite any inputs for which measured values are available provides a comprehensive and efficient setup to evaluate motor vehicle collisions.

Msmac3D has achieved impressive accuracy in the general case using automatically approximated vehicle properties as it provides impact speed and impact speed change results that correlate within +/‑10% of the corresponding measurements in more than 25 instrumented collision and rollover tests. These tests come from a variety of sources including the following:

Smith, R. A., Noga, J. T.
“Examples of Staged Collisions in Accident Reconstruction“,
from Highway Collision Reconstruction,
The American Society of Mechanical Engineers, Nov. 1980
McHenry, B.G, McHenry, R.R.,
“RICSAC-97, A Reevaluation of the Reference Set of Full Scale Crash Tests“,
SAE Paper No 97-0961, Detroit 1997
Larson, Smith, Werner and
Fowler, “Vehicle Rollover Testing, Methodologies in Recreating Rollover Collisions“,
SAE Paper 2000-01-1641
2002 SCARS Test2
2010 ARCCSI Test8
Toyota PU Rollover Test
2014 NAPARS Test 2
2011 SATAI Offest
2008 SCARS Crash 3
2013 Tennessee Highway Patrol
2007 SCARS Crash 4
2007 NYStars
http://tucrrc.utulsa.edu /,
University of Tulsa’s Crash Reconstruction Research Consortium

A paper will be published by McHenry Software providing more information and documentation on these validation tests shortly after the official release of the msmac3D program.

Also please read paper prepared for the 2015 IPTM Special Problems Conference

“The Proper Use of Simulation Technology for Collision and Rollover Reconstructions and Highway Safety”

The following are some time history plots of comparisons of msmac3D time history predictions from that IPTM paper with the full scale test measurements. These comparisons demonstrate good correlation of the predicted roll, pitch and yaw responses with the full scale test measurements.

In the Graphs, Blue Solid lines are full scale test measurements and the other dashed lines are the predicted results of mSmac3D.

SMAC3D: Combining SMAC and HVOSM into one program

In 1998, Brian McHenry was hired by CBS News to reconstruct the Princess Di accident for the television program “48 Hours”. At that same time Brian had been working on a 3D collision simulation program which combined the collision capabilities of SMAC with the 3 dimensional vehicle dynamics simulation capabilities of HVOSM.

Brian was provided the survey information for the tunnel, the vehicle information and we used the program, mSMAC3D, to simulate the vehicle traveling into the Pont de l’Alma road tunnel in Paris, France, and striking the support post (In that tunnel they do not have guardrails in front of the support posts). The results were presented and Brian answered questions in interviews on 48 Hours broadcast on June 11, 1998 and August 31, 1998.

The eighteen-month French judicial investigation which concluded in 1999 correlated closely with the speeds and findings of McHenry’s investigation and with the simulated reconstruction with the prototype mSMAC3D.

Until the early 2000s, the limitations in processing speed of personal computers limited the continued development of the mSMAC3D model to simple internal research. Since 2000, we have been testing and refining a 3D simulation and reconstruction tool which merges the strengths of SMAC and HVOSM into a single program.

Additionally, McHenry Software has added the following enhancements:

New 3D Graphics and graphical Interface for easy input and output and display of results.
Automatic generation of 3D inputs based on vehicle make, model and year.
- Validation comparisons of simulations based on the automatic inputs have accuracy within ±10% of the measured full scale tests.
Msmac3D includes the ability to edit any and all 3D inputs and override the automatically generated inputs.

For additional information, please see the features page. For any questions please use the Contact link in the top menu.