SUS 304鋼の高温多軸疲労寿命に及ぼす引張圧縮-ねじり負荷位相の影響
SUS 304鋼の高温多軸疲労寿命に及ぼす引張圧縮-ねじり負荷位相の影響
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拉压扭加载阶段对SUS 304钢高温多轴疲劳寿命的影响
DOI：
10.2472/jsms.36.376
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
和夫 桑原
中科院分区：
文献类型：
--
作者：
明人 新田;隆志 緒方;和夫 桑原
为了研究轴向扭转应变阶段对高温双轴低周疲劳寿命的影响，在550°C下对SUS 304不锈钢进行了轴向扭转应变控制的疲劳试验，试验条件为轴向和扭转应变同相和异相。在试验结果的基础上，提出了双轴低周疲劳的一个判据，在Mises等效应变范围或最大剪应变范围相同的情况下，异相应变下的疲劳寿命比同相应变下的短。通过复型法观察试样表面的滑移带和微裂纹，这似乎是由于同相和异相应变之间宏观应变条件的差异引起的断裂模式的变化。因此，可以通过扩展Brown-Miller的等效剪应变理论来获得同相和异相双轴疲劳寿命的统一关联，该理论包含最大剪应变和最大剪切平面上的法向应变作为双轴载荷下控制疲劳裂纹萌生和扩展的因素。
In order to investigate the effect of axial-torsional straining phase on the elevated-temperature biaxial low-cycle fatigue life, axial-torsional strain controlled fatigue tests were conducted on SUS 304 stainless steel at 550°C under in-phase and out-of-phase conditions between axial and torsional straining. Based on the experimental results, a criterion of biaxial low-cycle fatigue was discussed in this study.The fatigue life under out-of-phase straining was found to be shorter than that under in-phase straining when compared at the same Mises equivalent strain range or maximum shear strain range. From the observation of slip-bands and micro-cracks on the specimen surface by means of a replica method, this appeared to be due to the change in fracture mode arising from the difference in macroscopic strain condition between in-phase and out-of-phase straining. Accordingly, a unified correlation for both the in-phase and out-of-phase biaxial fatigue lives could be obtained by expanding the Brown-Miller's theory of equivalent shear strain which contains the maximum shear strain and the normal strain across the maximum shear plane as the factors controlling the fatigue crack initiation and propagation under biaxial loading.