JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech III VEHICLE DYNAMICS Previous Question Paper (November/December - 2018 - R13)

What do you understand by modeling and simulation?

Explain the meaning of the following tire size codes: i) 10.00R20 14(G) ii) 480/80R46155A8

Explain the variation of longitudinal tire force with various slip angles in detail.

Describe about the tire vibration with suitable sketches.

State the importance of the eigen value and eigen vectors.

How will you compute the effective spring rate of a given vehicle?

Consider a car with the following specification, and find the axles load. m = 1245 kg, a= 1100 mm, a1= 1323 mm.

Define Tire Deflection.

What is roll axis?

Briefly explain the transient response characteristics of road vehicles.

Write a note on camber and camber thrust.

Discuss about the directional stability of Vehicle.

What is roll axis? Discuss vehicle under the action of side forces.

Derive a suitable expression to calculate the under steer coefficient. With that expression, compute the characteristics speed of an under steer vehicle.

Determine the longitudinal mass centre assuming the force under the front wheels is 2FZ1.

What are the tire coordinate frame and tire force system.

Prove the tire stiffness in the Z-direction.

A passenger car has a weight of 20.105 KN and a wheel base of 3.2 m. The weight distribution on the front axle is 53.5% and that on the rear axle is 46.5% under static condition. Determine the steady state handling behavior of the vehicle: (i) If the cornering stiffness of each of the front tyres is 38.92 kN/rad and that of the rear tyre is 38.25 kN/Rad (ii) If the front tyres are replaced by a pair of radial tyres each of which has a cornering stiffness of 47.82 kN/rad and the rear tyres remain unchanged.

Use the Lagrange method and find the equation of motion for the pendulum shown in Figure. The stiffness of the linear spring is k.

Discuss the stability of vehicle on a slope and running on a curved track.

Discuss the effect of roll axis and side forces acting on the vehicle.

A passenger car weighs 20 kN and has a wheel base of 2.8m. The center of gravity is 1270 mm behind the front axle. If a pair of radial ply tyres, each of which has a cornering stiffness of 45.88 kN/rad, are installed in the front and a pair of bias ply tyres each of which has a conrnering stiffness of 33.13 kN/rad are installed in the rear. (i) Determine whether the vehicle is understeer (or) oversteer. Also calculate the critical speed of the vehicle as appropriate. (ii) What would happen to the steady state handling characteristics of the vehicle, if the front and rear tyres are interchanged. (iii) Derive the formula used.

Write short notes on: i) Yaw velocity gain ii) Lateral acceleration gain iii) Curvature response gain for over steer, neutral steer and under steer.

Explain in detail i) Under steer ii) Over steer and iii) neutral steer applicable to steady state handling characteristics of a vehicle.

A car of total weight 19620 N runs at 72 km/hr round a curve so that its C.G. moves in a circle of 80m radius with its wheel axes at an angle of 10° to the horizontal. The C.G. of the car is 1 m above the ground and is midway between the axes. The wheel track is 1 m and the diameter of the wheels is 0.6 m and each pair of axle weighs 1962 N, and the radius of gyration is 0.25 m. Determine the normal reactions on each wheel taking into account the centrifugal and gyroscopic effect.

Explain about the distribution of weight of a three wheeled vehicle.

Derive an expression to compute the steer angle required to negotiate the given curve under steady state condition. With that explain under steer, neutral steer and over steer.

Explain in detail the directional stability of a vehicle.

Write short notes on steady state cornering.

Determine the load carried by wheels at the outer and inner sides and the max value of coefficient of adhesion if there is no side slipping when the vehicle weighing 17.795KN runs at 96KMPH round a circular path so that the C.G moves in a circle of 122 m with its wheel axes at angle of 120 to horizontal. Its C.G is 1.06 m above the ground level and wheel track is 1.3 m. Explain the forces or couple acting.