8 understeering and over steering

8 understeering and over steering

• 1.
  UNDERSTEERING AND OVERSTEERING EFFECTS
• 2.
  • While takinga turn the centrifugal force acting on the vehicle which produces a side thrust. • To sustain that force, the plane of wheel must make some angle with the direction of motion of the vehicle. • This is achieved by the distortion of the tyre which is flexible.
• 3.
  SLIP ANGLE orCREEP ANGLE CORNERING FORCE
• 4.
  Slip Angle: • Theangle through which the wheel has to sustain the side force is called slip angle or creep angle. In other words • The angle between direction of the motion of the vehicle and the center plane of the tyre is known as Slip Angle. • It ranges from 80 to 100 Direction of Heading Direction of Travel Contact Patch Slip Angle, Fy M z Pneumatic Trail, P Slip Region
• 5.
  CORNERING FORCE • Theforce produced due to this side thrust is known as cornering force. Cornering power=side force sustained/slip angle
• 6.
  Understeer: • When thefront slip angle is greater than that of rear, the vehicle tends to steer in the direction of side force. •Then it is known as understeer.
• 7.
  OverSteer: • When therear slip angle is greater than that of front slip angle, the vehicle tends to mover away from the direction of center path. •This is known as over steer.