A Model of Life Prediction for Fatigue-creep Interaction and Its Experimental Verification

Abstract

Abstract:

Based on the ductility exhaustion theory and damage mechanics, the correlation among the ductility consumption, damage, cycles and failure life of materials under fatigue-creep interaction was analyzed herein.And then, a model for fatigue-creep interaction life prediction was established.This model was very convenient for practical engineering applications because of its simple formation.Through fatigue-creep interaction experiments with smooth specimens of 1.25Cr0.5Mo steel at 540℃ and 520℃ under stress control, which used a trapezium waveform with the hold-time per cycle, the prediction of the failure life was carried out by this model. Compared with the experimental data, it is found that the predicted results are in good agreement with the experimental ones.Besides,this model can explain the life fluctuation under the same temperature and loading condition well.

Key words: fatigue-creep;ductility;damage;mean strain;life , prediction

摘要：

基于延性耗竭理论和损伤力学，对材料疲劳-蠕变交互作用下的延性消耗、损伤、循环周次和失效寿命之间的关系进行了分析，在此基础上,建立了一种疲劳-蠕变交互作用的寿命预测模型,模型形式简单,非常便于实际工程应用。通过1.25Cr0.5Mo钢光滑试样540℃和520℃环境下应力控制的梯形波加载试验，用该模型进行了失效寿命的预测，可以很好地解释相同温度和加载条件下的寿命波动，预测结果与实测结果符合较好。

关键词: 疲劳-蠕变, 延性, 损伤, 平均应变, 寿命预测

CLC Number:

Chen Ling, Zhang Xianming, Ouyang Ping. A Model of Life Prediction for Fatigue-creep Interaction and Its Experimental Verification[J]. China Mechanical Engineering, 2015, 26(10): 1356-1361.

陈凌, 张贤明, 欧阳平. 一种疲劳-蠕变交互作用寿命预测模型及试验验证[J]. 中国机械工程, 2015, 26(10): 1356-1361.

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