Comparative Study between Small Punch Tests and Finite Element Analysis of Miniature Steel Specimens

The experimental method of small punch tests (SPT) using miniature specimens has great advantages and broad application prospects for material research in space, nuclear plants and other extreme environments. However, at present, the application of this method lacks unified standards and norms, which affects its application effect. Based on these, the mechanical properties of phi 3 mm disks miniature specimens of SIMP steel with different thicknesses are investigated through SPT experiments, finite element modeling (FEM) analyses and scanning electron microscopy observations. All the results demonstrate that the relationship of the mechanical properties of standard tensile test samples derived from the data of small punch test is established, and the method of establishing this mechanical relationship is also provided. Most importantly, based on the shear stress analyses of FEM calculations, most mechanical properties, such as yield strength, ultimate strength, fracture toughness and elastic modulus, can be obtained directly through SPT experiments. These findings may improve the possibility of establishing a widely accepted program for obtaining basic materials properties from SPT experimental data by using FEM simulations and provide a new comparison scheme (or norm) for obtaining accurate data from miniature specimens.