McHenry Forum - Crash Reconstruction & Simulation

Q: In looking at the NHTSA crash test database site , I've noted several instances where one of the crush measurements was a negative value of significant magnitude. Can anyone explain why they report the value in this manner. All crashes are 30 mph or 35 mph rigid barrier impacts and in reviewing p...

I came across an old post (8/31/98) with some additional information in response to a question on 'MU for rotation': Aug 1998: This is prepared in response to a question on the tire model in SMAC and equations to use in a spreadsheet program. As Monday mornings normally go, the stuff is hitting the ...

Q: What is the mSMAC SNAG option and why do i need it? A: Intervehicle friction, as simulated by original SMAC and EDSMAC, is in the form of simple Coulomb friction. It requires the existence of a force perpendicular to the contact region and it is proportional to that force. (For additional informa...

A couple additional considerations when calculating or checking CRASH A,B crush stiffness coefficients: 1) Once you acertained the year/make/model, use medit32->Database->NHTSA Crash Tests w/Extended Data to check for your year/make/model of vehicle. (non McHenry Software users should check NHTSA Ve...

Q: How do I calculate CRASH Damage Analysis A & B coefficients? A: medit32 now includes a utility for the calculation of the CRASH damage analysis A,B coefficients for use with CRASH or other damage analysis programs. The utility program is contained on Tools->Lsqft - A,B Coeff Calculator . The ...

1) If you have updated to medit32 Thank you for your support! Starting 1 year from your initial receipt of medit32 (July/August 2009 or later) and 30 days prior to the renewal date, the software will notify you that you need to renew. Please be sure to renew before the expiration date and you can ta...

The following are some references on Heavy Truck Crash Tests. This is no way comprehensive. Please add to the list. Just a few references I found within arms reach. Truck Crash Testing, E. Franchini, SAE 700411 Truck Tests on Texas Concrete Median Barrirer, T.J. Hirsch, PB 220 853 Heavy Truck Pilot ...

There have been some experimental tests run on the effects of vehicles in proximity to trucks. A quick look brings the following reference: Aerodynamics of Passenger Vehicles in Close Proximity to Trucks and Buses Robert Heffley, Systems Technology (STI), SAE paper 730235 The full report was perform...

New: Use this link to go to the latest post on this thread To approximate the drag factor for a rotating vehicle, we caution against attempting to use any arbitrary % drag factors like: "50% to 80% of the standard drag factor" or "70-75% of the full drag". In our paper " CR...

The conventional form of vehicle damage analysis in the case of a central collision with a fixed, rigid object is based on the assumption of a full-term collision, during which the vehicle velocity is reduced to zero (e.g., figure 1). full term collision.jpg Figure 1 Full-Term Collision For the case...