核电站常用管道材料J-C本构模型参数识别及验证

Identification and verification of J-C constitutive model parameters for pipeline materials commonly used in nuclear power plants

针对核电站管道在受到地震等灾害产生的偶然冲击载荷作用时的应力流动与变形情况,采用电子万能试验机和高速拉伸试验机,分别对碳钢A106(A-106 GR.B)、不锈钢304L(A-312 TP304L)、合金钢A335(A-335 GR.P11)3种核电站常用的管道材料进行准静态拉伸与动态拉伸试验,并根据试验所得结果拟合建立了3种材料的Johnson-Cook(J-C)本构模型。利用Abaqus有限元分析软件建立管道的冲击模型,并通过冲击试验台架对仿真结果进行验证。结果表明,3种材料都出现了明显的应变率强化效应,A335的抗冲击能力更好一些,304L与A106抗冲击能力差别不大。试验结果与仿真结果吻合度良好,拟合得到的J-C本构模型参数可靠性较高,能够准确地描述材料在冲击载荷下的应力流动与变形行为,对核电站常用管道受冲击载荷作用仿真分析研究具有十分重要的意义。

In order to study the stress flow and deformation of nuclear power plant pipeline under the action of accidental shock load caused by earthquake and other disasters,the quasi-static and dynamic tensile tests were conducted on commonly used pipeline materials in nuclear power plants,namely carbon steel A106(A-106 GR.B),stainless steel 304L(A-312 TP304L),and alloy steel A335(A-335 GR.B)using an electronic universal testing machine for the quasi-static tests,and a high-speed tensile testing machine for the dynamic tests.Based on the test results,and the J-C constitutive model was successfully fitted and established for these three different materials.The impact model of the pipeline was established using Abaqus finite element analysis software,and the simulation results were validated through an impact test conducted on a test bench.The results show that obvious strain rate strengthening effect can be observed in the three materials.The impact resistance of A335 is better,and there is little difference between 304L and A106 in impact resistance.The test results are in good agreement with the simulated results.The parameters fitted in J-C constitutive model have excellent reliability,which can accurately describe the stress flow and deformation behavior of materials under impact load,and have important significance for simulation analysis of the commonly used pipelines in nuclear power plants under the action of impact load.