Zr-Sn-Nb薄片合金高温低周疲劳行为

采用Zr-Sn-Nb合金薄片漏斗试样,完成了室温和500℃高温下的低周疲劳试验,提出基于漏斗根部节点轴向应变的疲劳损伤等效假设。根据有限元分析,建立了Zr-Sn-Nb合金室温和高温下薄片漏斗试样测试应变到漏斗根部轴向应变的转换模型。结合低周疲劳试验结果,建立了在室温和500℃高温条件下用于估算Zr-Sn-Nb合金疲劳寿命的Manson-Conffin模型。结果表明:Zr-Sn-Nb合金具有循环稳定性;高温严重影响了Zr-Sn-Nb合金低应变幅下的疲劳寿命,随着应变幅的增加,温度影响趋弱。

Low Cycle Fatigue Behavior of Zr-Sn-Nb Slice Alloy at Elevated Temperature

A series of low cycle fatigue tests were carried out on small funnel-like slice-specimens of Zr-Sn-Nb alloy at room temperature and 500 ℃. Based on the local uniaxial strain of small funnel-like specimens, the fatigue damage equivalent hypothesis was given. Through finite element analysis, the strain conversion model for funnel-like specimens from uniaxial testing strain to local uniaxial strain was established, besides, the validity of finite element analysis was checked by the test results; with the results of test, Manson-Conffin model for Zr-Sn-Nb alloy strain fatigue life estimation was presented. The results show that, Zr-Sn-Nb alloy exhibites cyclic stability; elevated temperature shorten the fatigue life of Zr-Sn-Nb alloy seriously and temperature effect impairs gradully with the increase of strain amplitude.