A simplified analytical solution for strain conversion in miniaturized thin-plate creep tests

This study examines the steady-state creep behavior of miniaturized thin-plate specimens (MTPS) with varying geometries to assess the influence of fillet regions on high-temperature uniaxial creep. Specimens with different geometry configurations were tested under constant stresses of 70, 85, and 100 MPa at 600 °C. A simplified analytical method was developed to account for fillet contributions, enabling conversion of measured crosshead displacements to equivalent uniform-section strain values, and its accuracy was validated through finite element (FE) simulations. The experimental results indicate that an increase in the uniform gauge section length generally leads to a higher steady-state creep rate, whereas larger fillet sizes also tend to slightly increase the secondary-stage creep deformation, though the effect is less pronounced. Comparisons between the experimentally measured and converted data confirm that the proposed method effectively compensates for fillet effects, yielding stress exponents and minimum creep rates consistent with those of standard specimens. These findings highlight the significant role of specimen geometry in high-temperature creep and demonstrate the method's reliability for interpreting MTPS creep data.