Back Plate Thickness Research Articles

The optimization of two component composite armours

Summary This paper draws attention to the potential of two component composite armours for providing lightweight protection for vehicles and seeks to establish a method for optimizing the design of such systems. Using an existing theoretical model, expressions are developed for the optimum value of the front plate to back plate thickness ratio. The results of a programme of trials in which 7.62 mm ammunition was fired at a range of alumina/aluminium targets are presented. A good level of correlation is observed between the experimental results and the theoretical predictions.

Disc Brake Interface Pressure Distributions

The nature of the contact and pressure at the interface between the friction material pad and the disc rotor of a ‘spot’-type disc brake affects the performance of a brake in terms of torque, temperature distributions and wear. Interface contact and pressure distributions have been predicted for a particular design of floating caliper passenger car disc brake, using three-dimensional finite element analysis under static and dynamic brake actuation conditions. The influence of friction material compressibility, pad backplate thickness, coefficient of friction, caliper flexure, disc stiffness and actuating piston contact with the piston bore on the interface pressure distribution is examined. The effect upon brake performance is discussed in terms of ‘centre of pressure’ and corresponding braking torque, and in terms of observed effects such as temperature and wear distribution. The results confirm that in order to ensure consistent disc brake performance the interface pressure distribution should be carefully controlled by designing in mechanical rigidity, compliant friction materials and minimum compliance during brake operation.