Estimation of Residual Stresses in Railroad Commuter Car Wheels Following Manufacture

Abstract

Abstract A finite element simulation is presented for the prediction of residual stresses resulting from the heat treatment of railroad commuter car wheels during manufacture. The quenching and annealing segments of the wheel manufacturing process are simulated using a decoupled heat transfer and stress analysis. A set of baseline parameters which characterize geometry, material properties and quench characteristics is developed which are representative of current rim-quenching practice. Results indicate the formation of a layer of residual circumferential (hoop) compression to a depth of about 4 cm (1.5 inch) from the tread surface. Variations of these parameters which account for expected ranges in the manufacturing process are shown to have little influence on this finding. The as-manufactured net rim compressive residual stress may be reversed when subjected to service loading in railroad commuter operations. This situation is examined in a companion paper. Tensile stresses at the wheel tread create an environment conducive to the formation of surface cracks that may threaten the safety of train operations. The results of the studies presented in this paper are required to define the initial conditions for analyses of how service conditions may act to change the as-manufactured residual stress state.