Low Cycle Fatigue Life Prediction of Notched DZ125 Component Based on Combined Critical Distance-Critical Plane Approach
Low Cycle Fatigue Life Prediction of Notched DZ125 Component Based on Combined Critical Distance-Critical Plane Approach
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DOI：
10.3901/jme.2013.22.109
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发表时间：
2013
影响因子：
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通讯作者：
Jia Huang
中科院分区：
文献类型：
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作者：
Jia Huang
(CID：3)考虑到镍基定向凝固高温合金滑移系统的塑性流动和裂纹萌生机制，将“热点”概念和临界距离理论相结合，对DZ125缺口850(CID：145)的低周疲劳寿命进行了预测。滑移面上的损伤参数是最大可分辨剪切应变范围∆γmax。结果表明，“热点”法的预测能力是保守的，与Kt有关。分析结果表明，临界距离不仅与材料、破坏次数、应力比有关，而且与应力集中程度有关。以尖端缺口为标准样本或用统计平均法对临界距离进行处理，预测寿命的散布带均大于10，而以Kt修正的临界距离为基础，散布带增加到2。
(cid:3)Considering the plastic flow and crack initiation mechanism occurred on the slip systems of ni-base directionally solidified (DS) supealloy, the critical plane method with the combination of “hot point” concept and theory of critical distance(TCD) is conducted on low cycle fatigue (LCF) life prediction of notched DZ125 at 850 (cid:145). The damage parameter on slip planes is the maximum resolved shear strain range ∆γ max . The obtained results exhibits that the prediction ability of the “Hot point” method is conservative and K t related. Furthermore, TCD is introduced and the analysis results show that the critical distance is not only related to material, failure cycles and stress ratio, but also related to the degree of stress concentration. Using the sharp notch as standard sample or dealing critical distance with statistics average method, the scatter band of predicted life is more than 10. However, based on the K t modified critical distance, the scatter band is increased to 2.