ASC Paper Notes
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The distance of the NSP from the front axle is determined by the following equation   Assuming the tires in the front and back are the same model, and thus the cornering stiffness values are the same, the equation simplifies down to 1/3WB. |
The location of the CG relative to the NSP determines the characteristic of the yaw response. This can be summarized in variables known as the static margin and the understeer coefficient
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This means that the K value CAN be negative at the start but quickly become positive given increasing lateral acceleration.
This is still indicative of a stable vehicle.
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The diagram that will be used for reference here is as follows.
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The vehicle pictured above is in a right-hand turn, with subscript “i” denoting inside and “o” denoting outside. The height of the CG is HG and the distance from the front axle to the CG is LG.
Although slipping can occur before tipping (somehow, the paper says the largest value of a_y that the vehicle will experience is equal to the coefficient of lateral friction at the tires), it is still wise to design the vehicle to a higher a_y since tires can bump while sliding which can cause tipping.
In the analysis done in the paper, it was assumed the tires were not sliding, therefore allowing us to isolate and examine the lateral forces needed to tip the car. When this happens, WFi will be 0. This lateral acceleration can be expressed as Fc, measured in g’s (note this could be gravity using imperial units)
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The paper also explores how this lateral acceleration value, Fc, can be determined using the tipping table angle outlined in the regulations.
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For ASC regulations, the car must be able to withstand a 45-degree tipping table. This gives us an Fc of at least 1.
Braking Weight Transfer
Reading List
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