A Three-Dimensional Finite Element Approach to Drum Brake Analysis

Abstract

This paper outlines the extension of the ‘GAPFRIC’ concept to model in three dimensions the frictional interface between brake linings and drum. Analyses have been completed to investigate the combined axial and circumferential expansions on the local surface temperatures, interfacial pressure distributions and consequent brake performance. Predicted results of the simulation applied to a S cam-operated brake indicate that in the circumferential direction higher pressures are attained at the ends of the linings of the leading shoe than in its central region. Higher pressures are also reached at the cam end of the trailing shoe. Axial pressure variations also exist across both shoes. The coupling of pressure and temperature variations together with the effects on frictional changes over the lining surface produce changes that result in the frictional drag per unit area tending to be reasonably constant over the interface between drum and lining. These results have been validated by comparison of the calculated brake performance with that measured on a brake mounted on a dynamometer.