钛合金材料弹塑性修正因子研究

Research on Elastoplastic Strain Correction Factor of Titanium Alloy

对核级设备的疲劳分析计算通常是采用美国工程师机械学会(ASME)或法国《压水堆核岛机械设备设计和建造准则》(RCC-M)规定的简化弹塑性疲劳分析方法。进行简化的弹塑性疲劳分析需要确定弹塑性修正因子(Ke)及其相关参数。规范给出了核级设备常用材料的Ke基于大量试验数据拟合的经验公式及其相关系数。但目前,规范并没有提供钛合金材料的这些相关数据。由于试验获取钛合金材料Ke需要耗费大量时间和物力,因此,通过数值分析方法获取钛合金材料的Ke,并验证核级设备常用材料规范提供的经验公式是数值分析方法获取Ke的包络值,同时确定包络的最小保守裕量。以此为依据,确定钛合金材料Ke的表达式及其相关系数,以满足钛合金TA17的简化弹塑性疲劳分析要求。

The ASME and RCC-M codes include a detailed fatigue evaluation based on elastically predicted stresses. A prerequisite for the fatigue analysis is that the primary-plus-secondary stress range does not exceed 3Sin. If this limit is exceeded, the code provides ＂simplified Elastoplatie Analysis＂ rules for the fatigue evaluation. A Kc penalty factor is the most important parameter of this method. The ASME and RCC-M codes provides the codified expressions of Kc and material parameters for general materials of nuclear-components, but there is no expressions and material parameters for the Titanium Alloy. The determination of Kc expressions and parameters for Titanium Alloy is discussed. A exemplary verification calculations of general materials that have been performed and the conservative allowance is obtained. Based on the results, the proposed Kc factors of Titanium Alloy has been determined and deliver the same sufficiently conservative results.