Saw a post on Facebook in June 2020 NAPARS page about damage measurement:
- damage measurement.png (361.26 KiB) Viewed 116 times
- Measuring Crush.
- An investigator for NHTSA came to an inspection of this car which experienced a serious frontal impact. He brought a pair of folding music stands, and set them at a common distance from the undamaged rear axle to serve as a reference baseline. He tied a string at bumper height and used tape on the string to flag the locations for his 6 crush measurements (equidistant on the original face, now distorted on the car). Low tech, but also low cost, easily transportable on a plane, highly adjustable, easy to explain, and repeatable enough for the task of measuring crush. He let me take a picture of it. Thanks, NHTSA-guy!
- (i just browsed down to the page...LOTS of informative posts by Wade on that Facbook thread...here's the specific thread on Facebook to Measuring Crush)
- An investigator for NHTSA came to an inspection of this car which experienced a serious frontal impact. He brought a pair of folding music stands, and set them at a common distance from the undamaged rear axle to serve as a reference baseline. He tied a string at bumper height and used tape on the string to flag the locations for his 6 crush measurements (equidistant on the original face, now distorted on the car). Low tech, but also low cost, easily transportable on a plane, highly adjustable, easy to explain, and repeatable enough for the task of measuring crush. He let me take a picture of it. Thanks, NHTSA-guy!
- Love it! I'll take on ANY cloud scan in damage analysis with my plumb bob and ruler! There have been tests/papers on comparing different measurement techniques when applying damage analysis and it all boils down to that a cloud scan for data in crush analysis is like using an electron microscope to measure something to the nearest inch!! what's the point? Whole lotta gigabytes for a crude technique.(yea they sure make purdy looking pictures which has jury appeal!!)
CRASH (on which all damage analyses techniques are based) was invented by Ray McHenry as a quick/fast way to get starting speeds for NHTSA to start a SMAC analysis!- ...and yea, NHTSA decided crude was OK and Good enough for their NASS statistical studies mainly because they simply wanted/needed uniform interpretation of crash evidence so they could look for trends, etc. etc. (see our many papers on CRASH
..now fast forward 40+ years and software vendors and others peddle CRASH and CRASH clones as primary reconstruction techniques for individual cases...sure the convenience of ONLY needing to look at the damage (whereas actually
- ...and yea, NHTSA decided crude was OK and Good enough for their NASS statistical studies mainly because they simply wanted/needed uniform interpretation of crash evidence so they could look for trends, etc. etc. (see our many papers on CRASH