中文摘要：

对N18锆合金和SAPH440板材采用薄片漏斗试样进行了室温下的等幅低周疲劳试验，基于局部应力、应变相等的疲劳损伤等效原理，建立了用于估算N18和SAPH440材料疲劳寿命的Manson．Coffin模型和循环应力一应变方程。对于符合Masing律的材料，提出了一种获得循环本构关系的新方法，用转子材料B65A．S在300℃高温下的低周疲劳试验进行了验证。通过基于标定循环本构关系的有限元分析，建立了两种材料薄片漏斗试样平均应力到漏斗根部轴向应力、测试应变到漏斗根部轴向应变的转换模型。完成了SAPH440材料等直圆棒试样的低周疲劳试验，证明了采用薄片漏斗试样的低周疲劳测试新方法具有较高的精度。

英文摘要：

A series of constant amplitude low cycle fatigue tests for thin funnel-like plates of N18 zircaloy and SAPH440 steel were carried out. Based on the principle of fatigue damage equivalent on local stress and strain, Manson-Coffin model of strain fatigue life prediction and the equation of cyclic stress-strain relationship for the two materials were established. A new method to obtain cyclic constitutive relationship for a material obeying Masing law was proposed, and experiments on low cycle fatigue of a turbine rotor steel B65A-S at 300~C were employed to verify the validity of this method. According to the finite element analysis on the basis of calibrated cyclic constitutive relationship, two types of transforming models from mean stress of a thin funnel-like plate to local axial stress at the root of the funnel and from measuring strain to local axial strain at the root of the funnel for the two materials were set up. Finally, low cycle fatigue tests for straight round bars of SAPH440 steel were completed, and the accuracy of the new test method for low cycle fatigue of thin funnel-like plates was completely certificated.