Based on Micromechanical Damage of Experimental Study on 20 Steel Notched Specimen's Acoustic Emission Characteristics

Abstract

Based on the Gurson-Tvergaard-Needleman micromechanical damage model, taking void growth ratioVGas the damage variable established acoustic emission (AE) quantitative evaluation model. Taking steel 20 notched bar specimens tensile process as example, get AE information from yield to fracture process. Using ABAQUS analyzed the meso-damage process during tensile process of the specimens, and get the numerical solution of meso-damage parameters. Based on AE testing and the results of Finite Element Simulation, established the quantitative evaluation formula ofVGand AE cumulative hitsNduring 20 steel notched specimens tensile process. Result shows that, 20 steel from yield to fracture damage, the relationship betweenNandVGis divided into two stage, namely linear damage stage and nonlinear damage stage. When theNreaches 61, the material is at the transition stage from linear damage stage to nonlinear damage stage.

Thermally Activated Crack Growth and Fracture Toughness Evaluation of Pipeline Steels Using Acoustic Emission

“…The study of the accumulation of microcracks with the help of AE before the initiation of a macrocrack is the subject of many scientific papers [18,25,[56][57][58]. However, the AE method is still often used only as an indicator of the catastrophic destruction of real bodies, and the diagnostic results are compared with some standards.…”