ABSTRACT

An experimental investigation has been undertaken to determine the effects of fatigue on the high strain-rate material properties of high-performance steel used in modern naval vessel structures. A novel methodology to conduct tensile testing at low and high strain-rates on fatigued specimens was developed. A bespoke Split Hopkinson’s Tension Bar clamping arrangement was designed to undertake the necessary high strain-rate testing of flat dog-bone specimens. Analysis of the microstructure of the specimens was performed alongside a comparison on the strain-rate sensitivity of the tested DH36 steel against other literature sources. Testing revealed no statistically significant effect of high cycle fatigue at high strain-rate as determined by a two-sample t-test, but revealed a possible effect on quasi-static material properties. The findings of this novel comparison between fatigued and virgin material properties of shipbuilding steel provides decision-makers and researchers with an understanding on the effect of fatigue on high strain-rate material properties.

摘要

已经进行了一项实验研究，以确定疲劳对现代海军舰船结构中使用的高性能钢的高应变率材料性能的影响。开发了一种在疲劳样品上以低应变率和高应变率进行拉伸测试的新方法。定制的Split Hopkinson张力杆夹紧装置设计用于对扁平的犬骨标本进行必要的高应变率测试。对样品的微观结构进行了分析，同时对测试的DH36钢与其他文献资料的应变率敏感性进行了比较。测试表明，在高应变率下，高循环疲劳在统计学上没有显着影响，这是由两个样本的t确定的。试验，但揭示了对准静态材料性能的可能影响。船用钢的疲劳和原始材料性能之间的这种新颖比较的发现为决策者和研究人员提供了关于疲劳对高应变率材料性能的影响的理解。