Fracture strain of gun steel for ultra-high-pressure vessels considering triaxiality effect

Abstract

To better understand the local failure of ultra-high-pressure vessels, the ductile fracture behavior of a gun steel, PCrNi 3 MoVA used for ultra-high-pressure vessel in China, was studied through experimental and numerical investigations. Tests on smooth and notched specimens of different notch radius values were performed, and the stressstrain states of specimens in the loading history were obtained through finite element analysis. Fracture was identified by means of comparing the engineering stress versus the strain obtained from tests with the finite element analysis results. The effect of triaxiality on the ductile fracture behavior of PCrNi 3 MoVA was discussed. Finally, a new plastic design-by-analysis method considering triaxiality effect was proposed to protect against local failure of ultrahigh-pressure vessels.

Effect of void in deformation and damage mechanism of single crystal copper: a molecular dynamics study

“…In comparison, void shrinkage has been reported due to dislocation adsorption in SC aluminium and polycrystalline copper [15,16]. Analytical and experimental studies of the triaxial deformation reported that triaxial stress enhances the void growth rate in the plastic field [17,18]. In the triaxial state, the material cannot stretch so much along the particular direction; therefore, such a condition imparts sudden fracture in the materials.…”