Construction of whole stress-strain curve by small punch test and inverse finite element

Small punch test is applied to estimate mechanical properties and damage evolution by a miniature specimen. Combining small punch test and inverse finite element, the elastoplastic parameters in Hollomon model and damage parameters in Gurson-Tvergaard-Needleman (GTN) model were identified by the undamaged and damaged stages of the load-displacement curve. Then, the whole stress-strain curve of 316L austenitic stainless steel was constructed based on finite element simulation of a tensile specimen considering the constructed Hollomon model and GTN model. To validate the constructed whole stress-strain curve, standard tensile test was performed as a control group. The result demonstrates that the constructed stress-strain curve is in agreement with the experimental data obtained by standard tensile test. Finally, the plastic damage distribution and fracture mechanism of the miniature specimen were analyzed to understand the damage evolution of small punch test.