Considerations on stress triaxiality variation for 2P armor steel

Innovative Ideas in Science 2016

Zichil, V.^1 ; Coseru, A.^2 ; Nedeff, F.^2 ; Tomozei, C.^3

Vasile Alecsandri University of Bacau, Department of Economical Engineering, Mechatronics, Bacau

600115, Romania^1

Vasile Alecsandri University of Bacau, Bacau

600115, Romania^2

Vasile Alecsandri University of Bacau, Department of Environmental Engineering and Mechanical Engineering, Bacau

600115, Romania^3

关键词: Equivalent stress;    Hydrostatic stress;    Invariant of stress;    Lightweight armors;    Stress triaxiality;    Tensile specimens;    Variation function;    Von mises criterion;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/200/1/012066/pdf
DOI  :  10.1088/1757-899X/200/1/012066

来源: IOP

【 摘 要 】

Stress triaxiality is considered an invariant of stress, defined as the ratio of hydrostatic stress (hydrostatic pressure by other authors) and the equivalent stress (usually calculated using von Mises criterion). If the values of the main three stresses have comparable sizes, stress triaxiality can be also calculated using the first invariant of the stress tensor. Despite that the stress triaxiality is an invariant, the authors have determined experimentally and analytically its variation with the force at the tensile test, but also with the radius of notches caused in the specimen. 2P armor steel being used in lightweight armor, these notches occur after shocks with foreign objects. Furthermore, the authors have revealed the stress triaxiality variation function of the test type. The tests were performed on tensile specimens loaded for tensile test, pure torsion test, 25% tensile - 75% torsion test, 50% tensile - 50% torsion test, 75% tensile - 25% torsion test. The mathematical model used was designed by Xue.