Search found 1792 matches
- Fri Jun 19, 2009 11:34 am
- Forum: Specs, Crash Tests, Etc.
- Topic: Friction decrement at high speeds?
- Replies: 0
- Views: 2065
Friction decrement at high speeds?
The friction decrement with speed is normally associated with wet pavement. From a discussion from our m-smac user's manual on friction loss with speed: In general, on wet surfaces, the effective tire-surface friction coefficient decreases with speed and c (card 12:field 7) can be used to simulate t...
- Fri Jun 19, 2009 11:26 am
- Forum: Damage Analysis, CRASH
- Topic: Should a CRASH type damage analysis include induced damage?
- Replies: 4
- Views: 11448
Should a CRASH type damage analysis include induced damage?
2 words of wisdom on CRASH type damage analysis (whatever flavor: EDCRASH, WinCRASH, etc): Be Careful! In 1988, Tumbus and Smith wrote SAE paper 880072: Measurement protocol for quantifying vehicle damage from an energy basis point of view ]. In the paper they presented some ideas for a standardized...
- Fri Jun 19, 2009 11:11 am
- Forum: Simplified Momentum Analysis, PC-Crash, Virtual Crash
- Topic: Some Simplified Momentum Assumption Misconceptions
- Replies: 6
- Views: 23867
Some Simplified Momentum Assumption Misconceptions
New: Use this link to go to the latest post on this thread Some Simplified Momentum Misconceptions: And please note this is not to dismiss simplified momentum analysis, it is to help all who use it to understand the assumptions, to encourage that they test a range of assumed input numbers to reveal...
- Fri Jun 19, 2009 11:11 am
- Forum: Simplified Momentum Analysis, PC-Crash, Virtual Crash
- Topic: Some Momentum Misconceptions
- Replies: 3
- Views: 2040
Some Momentum Misconceptions
Some comments on Momentum analysis: (1) The collision between two vehicles is not the same as a collision between two pool balls. More like two crushable rectangular boxes on wheels. And vehicles are not 'balls' or 'points', they are finite dimensioned crushable objects which may behave quite differ...
- Fri Jun 19, 2009 11:05 am
- Forum: Highway Safety
- Topic: Effects of Speed on Accident Frequency?
- Replies: 5
- Views: 13310
Effects of Speed on Accident Frequency?
CASR Speed Study In 1994 & 1998 McHenry Software participated in a study of crashes with the Road Accident Research Unit (RARU) of the University of Adelaide, Australia. They now go by the name Centre for Automotive Safety research (CASR) Summary The Road Accident Research Unit at Adelaide Univ...
- Fri Jun 19, 2009 11:01 am
- Forum: Specs, Crash Tests, Etc.
- Topic: Coefficient of friction of soft soils?
- Replies: 0
- Views: 2718
Coefficient of friction of soft soils?
For historical information, check out " Roadside Design for Safety " by Stonex (1960). It may be in other Stonex papers (some published through SAE since they include a lot of history on crash safety research). In the 1960 paper he towed vehicles sideways through wet and dry sod. In the St...
- Fri Jun 19, 2009 10:31 am
- Forum: General Topics
- Topic: Location of Gouges relative to Point of Impact?
- Replies: 0
- Views: 2556
Location of Gouges relative to Point of Impact?
Q: Assuming that a t-boned vehicle created a rim gouge from the impact, how far (laterally) would you expect the vehicle to have traveled prior to commencing the gouge? A: Some things to consider in relation to the location of a gouge mark to the initial point or area of impact: 1) Impact/separation...
- Fri Jun 19, 2009 10:23 am
- Forum: Damage Analysis, CRASH
- Topic: Does CRASH/EDCRASH include restitution?
- Replies: 1
- Views: 3091
Does CRASH/EDCRASH include restitution?
Q: Does CRASH/EDCRASH include restitution? A: NO! Restitution is not included in the fundamental equations of CRASH. Restitution is NOT included in any commercial version of CRASH. Restitution consists of two separate aspects: A partial dimensional recovery and A partial restoration of kinetic ener...
- Fri Jun 19, 2009 10:17 am
- Forum: General Topics
- Topic: Photogrammetry transformation matrix?
- Replies: 0
- Views: 2071
Photogrammetry transformation matrix?
The fundamental principle used by photogrammetry is that through "known" distances into and across a photograph, you can traingulate to determine "unknown" distances in a photograph. Check out Northwestern and look for 'Perspective Grid for Photographic Mapping of Evidence' it to...
- Fri Jun 19, 2009 10:07 am
- Forum: General Topics
- Topic: DeltaV in terms of G's?
- Replies: 0
- Views: 3733
DeltaV in terms of G's?
Q: I am used to discussing Delta -V for the forces on a person in a crash. Another expert is using G's. What is the conversion from one to the other? A: DeltaV, or Impact speed change, is normally associated with a collision. (to avoid those among you who will say `but you encounter a DeltaV when br...