PhD. Transactions of Machine Elements Division. Lund 1976

The following papers are included in this dissertation:

• On Optimum Design of Disc Brakes. Journal of Engineering for Industry. Trans. ASME, vol. 96, no 3,pp 863-869.
• Temperature Distribution in Disc Brakes. Transactions of Machine Elements Division. Lund 1976.

Abstract:

The temperature distribution in brake discs is studied. Mainly the maximum surface temperature is given as a function of the disc width, the braking time, and the retardation all in non-dimensional form.

Also such phenomena as varying thermal properties, varying brake torque, and different pad shape are considered. The temperature variation in peripheral direction is calculated, and diagrams showing the distribution of heat among the disc and the pads given.

Experiments were made to verify the theoretical calculations. For thick discs the temperature was measured by a thermocouple , and in other tests an infrared thermometer was used for both thin and thick disc.

Optimum design methods are given. Here either the extension or the weight is the limiting factor.

• Stresses and Cracks in Brake Disc. Transactions of Machine Elements Division. Lund 1976.

Abstract:

Stresses in brake discs are studied. Mainly stresses due to temperature differences are treated, but diagram over stresses due to the rotational velocity and the brake torque are also given.

Both pure elastic and elasto-plastic thermal stresses are treated. The elastic stresses are given for different disc widths, braking times, and retardations, all in non-dimensional form, while for the elasto-plastic stresses different materials are studied also. The material parameter is the inclination of the stress-strain curve in the plastic region over the modulus of elasticity.

The maximum tensile stresses in the disc surface after plastic deformations are given. If these stresses are above the tensile rupture limit cracks will arise. Crack might also appear from fatigue.

Tests, where theoretical and experimental crack limit stresses were compared, are made. The agreement between calculations and tests is good.