EFFECT OF GEOMETRY ON THE PREPARATION OF FATIGUE SPECIMENS WITH PREDETERMINED SURFACE ROUGHNESS

Abstract

In the present study, the applicability of the design of experiments (DOE) approach to the design of the long fatigue specimens of austenitic stainless steels with controlled surface roughness has been studied. The response surface models which can predict the surface roughness parameters Ra and Rz as a function of the final cutting conditions (axial feed rate and radial cutting depth) of the lathe were obtained by the analysis of variance (ANOVA) for the experimental data. It was found that the surface roughness parameters Ra and Rz obtained by the model prediction were in good accordance with the experiments. However, special care should be taken to minimise the specimen deflection generated during the machining process. It was concluded that the response surface models obtained were applicable to design the long fatigue specimens with controlled surface roughness.