Bump Stop
Bump Stop
(OP)
Am I right in thinking that the load on a bump stop from say a large pothole or brick at speed would be the vertical G value multiplied by the wheel assy mass, rather than the wheel load. Would 3G not seem unreasonable?





RE: Bump Stop
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Bump Stop
RE: Bump Stop
TTFN
RE: Bump Stop
RE: Bump Stop
TTFN
RE: Bump Stop
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Bump Stop
RE: Bump Stop
Based on later life experience with heavy duty tractor/trailer axles/suspensions, I can tell you that once the bump stop is encountered, irrespective of whatever spring effect of the bump stop rubber might have, there is no suspension, and the axle in question begins to lift the entire trailer load by itself, while unloading the other axles, and if carried to infinity, would then support the entire trailer weight and transmit to that trailer any acceleration loads that the wheel encountered (pothole is a step function) that it could survive with or without bending or breaking said wheels, tires, or axles.
I've seen some pretty stiff axles badly bent when this problem was encountered.
Problem was fixed when the suspension was redesigned so that the parts that made contact with the frame were modified. The 'nuts up' U-bolts that held the suspension spring packs were the offending parts, not the bump stops-there were none. They became bump stops with no spring constant other than what it took to do the mushrooming that was evident, however. Changing to a 'nuts down' U-bolt type of suspension and taller spring shackles did away with the bent axles and mushroomed U-bolts.
rmw
RE: Bump Stop
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.