高韧性管道动态断裂的气体减压模式和材料韧性研究

天然气管道上动态裂纹扩展包含气体、结构和断裂的相互作用．因此,分析射流场分布特性及其与管壁开裂变形的相互作用是数值模拟过程的关键问题．随着钢管韧性等级的迅速提升和气体压力的不断提高,原有的经验公式乃至算法多数不再适用,亟需通过理论、试验和数值模拟给出新的扩展与止裂判据,以控制裂纹在管道上扩展的速度和距离．本文通过一系列的韧性试验校正了现行的管材韧性判定办法,并对不同工况下的裂纹动态扩展以及超声速射流场进行了数值仿真,以建立一套工程适用的评价体系。

STUDY ON DECOMPRESSION AND TOUGHNESS OF DYNAMIC FRACTURES FOR STEEL GAS PIPELINES

Dynamic crack propagation on a gas pipeline involves the interaction among fluid, structure and cracks. Understanding the aerodynamic characteristics and interactions between gas and the pipeline is a key to the construction of numerical simulation. As a result of the complication in a coupling solution of the matter, some simple empirical models have been developed to simulate the pressure distribution process, with tolerances that are acceptable in the past. However, the increase of transmission pressure makes the occurrence of supersonic jet stream only a matter of time. The previous empirical models are now facing challenges. This paper tries to simulate the state of dynamic crack propagation in reaction to supersonic jet steam, with the aim of calibrating the existing gas decompression model by simulating the flow of the jet stream interacting with the splitting pipeline.