How is self alignment torque calculated?
The self-aligning torque (SAT) may be defined as the product of the cornering force and the pneumatic trail.
What are the differences between aligning torque and self aligning torque?
Self-aligning torque is also referred to as aligning torque as well as SAT and Mz. At its essence, self-aligning torque is the torque (a force that produces rotation) developed by the tire when you’re cornering (which means turning). It’s your turn to go, so you rotate your steering wheel to make a simple turn.
What is cornering force and self righting torque?
Cornering force is generated by tire slip and is proportional to slip angle at low slip angles. Because the tire deformation tends to reach a maximum behind the center of the contact patch, by a distance known as pneumatic trail, it tends to generate a torque about a vertical axis known as self aligning torque.
What causes pneumatic trail?
Pneumatic trail is caused by the progressive build-up of lateral force along the length of the contact patch, such that lateral forces are greater towards the rear of the contact patch (though less so when the rear of the contact patch begins sliding) and this creates a torque on the tire called the self aligning …
What is meant by self aligning torque?
Self aligning torque, also known as aligning torque, aligning moment, SAT, or Mz, is the torque that a tire creates as it rolls along, which tends to steer it, i.e. rotate it around its vertical axis.
How do you calculate cornering force?
Like if you are taking a turn of radius r with velocity v and the mass of car is m then the cornering force will be mv^2/r and if you can provide this much force as a traction force between tyre and road then car will definitely take turn without sliding.
What is tire slip angle?
Slip angle This is defined as the angle (degrees) formed between the actual direction of travel of the wheel and the ‘pointing’ direction of the wheel (perpendicular to the axis of rotation). Whenever slip angle is introduced, the contact patch deforms as lateral forces act on the tyre.
How is camber thrust generated?
Camber thrust is generated when a point on the outer surface of a leaned and rotating tire, that would normally follow a path that is elliptical when projected onto the ground, is forced to follow a straight path while coming in contact with the ground, due to friction.
What is Caster trail?
Caster trail, also called mechanical trail, geometric trail, or simply trail, is the side view horizontal distance from the ground intercept of the steering axis to the contact patch center. This distance is partly determined by caster angle, which is the side view inclination of the steering axis from vertical.
What is self righting torque?
How do you calculate cornering stiffness?
The nominal cornering stiffness is equal to the side force in pounds divided by the slip angle in radians for small angles. For larger angles the rate of increase of perpendicular force with increasing angle falls off as “saturation” is approached.
What is self aligning torque?
Self aligning torque are also shown. Self aligning torque, also known as aligning torque, aligning moment, SAT, or Mz, is the torque that a tire creates as it rolls along, which tends to steer it, i.e. rotate it around its vertical axis.
How does inertia affect aligning torque?
In the low frequency range, n < 10 Hz, the aligning torque appears to be affected most by the inertia of the tire. A simple addition to the kinematic model may approximately describe the dynamic changes in the response of the moment.
When is the torsional angle of a tire the largest?
The tire torsional angle is largest at the instant when the side-slip angle, β, occurs, and its magnitude is the same as the side-slip angle, but after that decreases with tire rotation and becomes zero at steady state.
How do you calculate the magnitude of the torque?
The magnitude of this torque can be calculated as the product of the lateral force generated at the contact patch and the distance behind the wheel centre at which that force acts. This distance is known as the pneumatic trail.