The development of a material model for cast iron that can be used for brake system analysis

Abstract

This paper describes the methodology and reports the results of detailed thermomechanical finite element analyses of cast iron brake discs under repeated high g braking conditions. The thermal analysis allows for heat loss from the vanes in a back-ventilated disc design as well as heat transfer to other parts of the brake assembly. The cast iron material properties required for the non-linear structural analysis are generated by mechanical tests on samples cut from the brake disc. The material model developed by the authors allows for the variation of flow stress with temperature and for the different yield properties of cast iron in tension and compression. The finite element results, derived from a preliminary investigation, indicate regions of high plastic strain accumulation which may lead to disc crazing and/or cracking and enable comparisons to be made between back- and front-vented rotor designs.