Extracting ductile fracture toughness from small punch test data using numerical modeling

This paper presents a numerical method to extract ductile fracture toughness from notched small punch test data using FE ductile damage analysis based on the stress-modified fracture strain model. To validate the proposed method, analysis results are compared with series of mechanical (notched tensile, fracture toughness and small punch) test data for three different materials; low alloy steel SA508 Gr.3, TP316L austenitic stainless steel and CF8M cast austenitic stainless steel. Comparison with experimental fracture toughness data shows that the proposed method can predict fracture initiation values relatively well and tearing resistance conservatively.