Optimization of Hollow Specimen Dimensions in Torsion Testing of AISI 1020 Steel using Grey Relational Analysis

This paper investigates the effects and parametric optimization of specimen dimensions for torsion testing of AISI 1020 steel using grey relational analysis. Four dimension parameters viz. outer diameter, inner diameter, useful length, fillet radius are considered and experiments are conducted based on L9 orthogonal array (OA).Torsion testing responses viz. modulus of rigidity (G), yield shear stress (�y), ultimate shear stress (�ut) of hollow specimen are calculated for every experimental runs. For maximum �y and minimum G and �ut, specimen dimensions are optimized based on Taguchi method coupled with grey relational analysis. Analysis of variance (ANOVA) is performed to investigate contribution of each specimen dimension on the output parameters and observed that outer diameter is significant specimen dimension that affects the responses. Confirmation test using optimal specimen dimensions shows good agreement to the predicted value.