As the extensive applications of thick steel plate and the rapid development of steel structures in cold regions, low temperature and large plate thickness become important factors for the brittle fracture of steel plate. The current design code still adopts impact toughness index to guide the material selection. However, fracture toughness index based on fracture mechanics can make a more accurate evaluate on the fracture failure. A quantitative method for selection of thick plate considering the brittle fracture is proposed in this paper after the results of fracture toughness index CTOD tests at low temperatures. Adverse effects of plate thickness and the concept of ductile-brittle transition temperature are supplemented to the quantitative selection method. This paper provides references and ideas for further discussions and researches of material selection methods.%随着国内钢结构厚板的大量应用和我国大范围低温区域的建筑业快速发展,低温环境和板厚增大逐渐成为钢板脆性断裂的重要因素.现行规范中仍采用冲击韧性指标来指导选材,而基于断裂力学理论的断裂韧性指标能更准确地评定断裂破坏的发生.本文在钢结构厚板低温断裂韧性指标CTOD试验结果的基础上提出了一套定量化的钢厚板防脆断的选材方法,并从厚度因素的不利影响以及引入韧-脆转变温度等方面对该定量方法进行补充和完善,为选材方法的进一步研究提供了依据和思路.
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