摘要
破前漏(LBB)技术广泛应用于核电厂的高能管道上,管道在复杂工况下的裂纹稳定性是LBB研究的核心问题之一,而管道材料的断裂阻力曲线(J-R曲线)是其稳定性分析的重要基础.本文以铁素体钢A533B为研究对象,拟采用Gurson损伤模型模拟紧凑拉伸试样在拉力作用下的断裂过程,并研究Gurson模型参数对计算结果的影响.计算结果表明:材料的初始孔隙率f_0对计算结果的影响最大,当孔隙率逐渐增大,裂纹扩展向失稳发展,而临界孔隙率f_N仅影响裂纹初步扩展的J值;其次的影响参数是载荷步控制参数α,随着α增大,裂纹扩展模拟朝着稳定与收敛方向发展.本文的模拟结果可用于确定材料的Gurson模型参数,为管道的裂纹扩展分析作基础.
Leak before break （LBB） is widely used in high energy pipes of nuclear plant, and crack stability of pipe under complex loading is the key issue of LBB, for which the fracture toughness curve of pipe material is the impotent base. Ferdtic stainless steel S355B was investigated, and the failure process of contact specimen made of S355B was simulated combined with Gurson model, for which parameter study was explored. The calculation results show that the most sensitive parameter is initial void ratio f0 in Gurson model, and when f0 increases, crack develops to instable extension. The second important parameter for calculation result is load control parameter α, and crack develops to stable and convergent status with increasing α. The minor parameter is critical void ratio fN, which has almost no effect on results. The analysis process in this paper can be used to determine parameters in Gurson model, which forms the base of crack failure analysis of pipe.
出处
《力学季刊》
CSCD
北大核心
2013年第4期694-697,共4页
Chinese Quarterly of Mechanics
基金
大型先进压水堆核电站国家科技重大专项(2011ZX06002-010)
