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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.
The broken front leakage (LBB) technology is widely used in high-energy pipelines of nuclear power plants. The crack stability of pipe under complicated working conditions is one of the core issues in LBB research. The fracture resistance curve (JR curve) of pipe materials is stable The main basis of this paper is to investigate the fracture process of compact tensile specimens under the action of tensile force by using the Gurson damage model and to study the effect of Gurson’s model parameters on the calculation results.The calculation results show that : The initial porosity f 0 of the material has the greatest effect on the calculation results. When the porosity increases gradually, the crack growth progresses to the instability, while the critical porosity f_N only affects the J value of the initial crack propagation. The second influencing parameter is the load step control The parameter α, as α increases, simulates the propagation of the crack propagation in the direction of stability and convergence.The simulation results of this paper can be used to determine the Gurson model parameters of the material, which can be used as the basis for crack propagation analysis.