Dynamic modelling for TWIP steel with high-strength and high-toughness

Abstract

Since the traditional rock support materials lack insufficient deformability and strength to meet the support requirements of underground caverns, the development of novel metallic materials used for rock support have drawn research attentions. This paper focuses on the mechanical behavior of a novel steel with high-strength and high-toughness (HSHT) steel, HSHT600, at different temperatures (25 °C to 700 °C) and strain rates (4.2×10⁻⁴ s⁻¹ to 4000 s⁻¹). To demonstrate the superiority of the HSHT600, the steel named MG500 was chosen as the traditional rock bolt material for comparison. HSHT600 steel has a yield strength of 613.912 MPa (approximately 1.23 times that of MG500), a tensile strength of 1181.03 MPa (approximately 1.56 times that of MG500), and an elongation after fracture of 51.9% (approximately 1.93 times that of MG500). A series tensile tests and dynamic impact tests were conducted to develop a modified Johnson-Cook (MJC) model for Steel HSHT600. The Taylor impact test and numerical simulations with an Abaqus subroutine (VUMAT) code were carried out to verify the proposed constitutive and fracture damage models. Finite element modelling (FEM) simulations reveal that the failure modes and deformation predicted by the MJC model are in better agreement with the experimental results, especially it can model the super large plastic but non-necking deformation of Steel HSHT600. In addition, in terms of mechanical properties, Steel HSHT600 exhibits remarkable superiority over traditional rock support materials in strength, deformation capacity, and energy absorption capability. Its outstanding performance makes it a promising candidate for application in deep underground projects. Meanwhile, the MJC Model obtained in this paper is helpful for both further research and engineering application when doing a numerical study of Steel HSHT600 used for rock support.