How can I calculate CRASH A & B Coefficients?

Questions/Topics Related to the CRASH computer program
#CRASH #EDCRASH #PC-CRASH
MSI
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Joined: Thu Jun 18, 2009 12:37 pm

How can I calculate CRASH A & B Coefficients?

Post by MSI »

Q: How can I caculate A&B CRASH coefficients for Damage Analysis?
A: In the Tools menu of medit32 is a tool LSqft- A B Coefficient Calculator.
  • Lsqfit is a Least Square Fit routine for creation of A & B Crush Coefficient fits:
    • For b0,b1 fits, enter Crash test results in form: Residual Crush (in), Speed change (mph)
      For CRASH A,B coefficients calculated: Residual Crush (in), Speed change (mph), Test weight(lbs), Damage Width(in)
    An optional no damage intercept (mph) is then input
Program assumptions:
  • Speed change is to point of common velocity, Single point Crush is average crush
    • Program will calculate the natural and forced intercept b0,b1 fits
    If weight & width given, program will then calculate A,B CRASH coefficients
    • A graphical display of results can then be printed
CAUTION: Use of a single crash test is discouraged due to variations in crash test results. Damage analysis accident reconstruction techniques should be viewed as a Tool. Damage analysis should be used in combination with other accident reconstruction Tools.
We are adding a section in the Getting Started Manual on detailed instructions of the Tool and will post a link to this forum when completed.
The following is a sample output (shrunk to 50%)
lsqfit.jpg
lsqfit.jpg (22.98 KiB) Viewed 6745 times
CAUTION: The use of a single full-scale crash test data point for a given vehicle, combined with an assumption regarding a “no-damage” intercept, to calculate custom fitted CRASH coefficients for a particular vehicle must be recognized as a crude “first-approximation” procedure.

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