- #1
olechampion
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Hi, Working on my vehicle and have a theoretical question I'd like a 2nd opinion on. The physics question is how much influence the force of a bump has in conjunction with a perfectly tuned spring rate can have on ride quality (as crudely defined in vertical acceleration z force m/s squared). I.e. how important is spring rate in ride quality? To look at this problem I have outlined three bump scenarios each with different heights.
The objective is to keep vertical acceleration constant at .5 m/s squared
Solving For: Spring Rate
Three scenarios:
bump height: 0.25 inch
bump height: 1 inch
bump height: 2 inchIn all scenarios the bump width is the entire road (ie like going onto a new road or bridge)Constants
vertical acceleration m/s squared: .5
vehicle speed: 60 mph
Tire Stiffness:
Tire Diameter: 32.2 inches
Tire Overall Width: 9.3 inches
Tire Loaded Radius: 15.2 inches
Coefficient of Rolling Resistance: 0.012 (10.00 -20 BIAS)
Coefficient of Rolling Resistance: 0.008 (10.00 -20 RADIAL)
Cornering Coefficient (deg -1): 0.1370
Camber stiffness: 40 lb / deg
Vertical stiffness: 4935 lb / in
Rolling Circumference: 89.33071 in
Front Axle Weight: 6900 pounds
Rear Axle Weight: 13500 pounds
Suspension Travel: 4 inches
Length of shock extended: 18 inches
Length of shock compressed: 14 inches
Wheelbase: 241 inches
Dual Tires rear axle
Side question, any decent suspension calculators to estimate problems like this? Would be great to do a sensitivity analysis.
The objective is to keep vertical acceleration constant at .5 m/s squared
Solving For: Spring Rate
Three scenarios:
bump height: 0.25 inch
bump height: 1 inch
bump height: 2 inchIn all scenarios the bump width is the entire road (ie like going onto a new road or bridge)Constants
vertical acceleration m/s squared: .5
vehicle speed: 60 mph
Tire Stiffness:
Tire Diameter: 32.2 inches
Tire Overall Width: 9.3 inches
Tire Loaded Radius: 15.2 inches
Coefficient of Rolling Resistance: 0.012 (10.00 -20 BIAS)
Coefficient of Rolling Resistance: 0.008 (10.00 -20 RADIAL)
Cornering Coefficient (deg -1): 0.1370
Camber stiffness: 40 lb / deg
Vertical stiffness: 4935 lb / in
Rolling Circumference: 89.33071 in
Front Axle Weight: 6900 pounds
Rear Axle Weight: 13500 pounds
Suspension Travel: 4 inches
Length of shock extended: 18 inches
Length of shock compressed: 14 inches
Wheelbase: 241 inches
Dual Tires rear axle
Side question, any decent suspension calculators to estimate problems like this? Would be great to do a sensitivity analysis.