Occurrence of Dynamic Shear Bands in AISI 4340 Steel under Impact Loads

• 作者: Akindele Odeshi Daniel Odoh Gbadebo Owolabi Horace Whitworth
• 来源期刊: 力学国际期刊(英文)
• 学科: 工学
• 关键词: ADIABATIC Shear Band Finite Element MODEL Strain HARDENING Thermal SOFTENING Johnson-Cook MODEL AISI 4340 STEEL
• 年，卷（期）: lxgjqkyw,（2）
• 页码范围: 139-145
• 页数: 7页
• 分类号: TG14

摘要

In this study, occurrence of adiabatic shear bands in AISI 4340 steel under high velocity impact loads is investigated using finite element analysis and experimental tests. The cylindrical steel specimen subjected to impact load was divided into different sections separated by nodes using finite element method in ABAQUS environment with boundary conditions specified. The material properties were assumed to be lower at the section where the adiabatic shear bands are expected to initialize. The finite element model was used to determine the maximum flow stress, the strain hardening, the thermal softening, and the critical strain for the formation of adiabatic shear bands. Experimental results show that deformed bands were formed at low strain rates and there was a minimum strain rate required for formation of transformed band in the alloy. The experimental results also show that cracks were initiated and propagated along transformed bands leading to fragmentation under the impact loading. The susceptibility of the adiabatic shear bands to cracking was markedly influenced by strain-rates. The simulation results obtained were compared with experimental results obtained for the AISI 4340 steel under high strain-rate loading in compression using split impact Hopkinson bars. A good agreement between the experimental and simulation results was obtained.