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通过对广义应变能损伤函数(GSEDF)法进行分析,用非弹性应变能表征低周疲劳(LCF)损伤,提出了一种高温低周疲劳-蠕变(LCF-C)寿命预测的改进型GSEDF模型,修正了GSEDF法中的能量参数,使其与工程实际更吻合。所提出的模型具有模型参数少、适用性广和试验数据利用率高等优点,且能综合反映加载方式、保载时间和平均应力的影响。最后,应用该模型对文献试验数据和轮盘用GH4133高温合金在不同温度和应变比(应力比)下的疲劳-蠕变寿命进行了预测,预测结果与实测结果吻合较好,精度明显优于GSEDF模型、SWT模型、应变能频率修正法和塑性应变能密度法。
By analyzing the generalized strain energy damage function (GSEDF) method and using the inelastic strain energy to characterize the low-cycle fatigue (LCF) damage, an improved GSEDF with high temperature and low cycle fatigue-creep (LCF-C) Model, the energy parameters in the GSEDF method are modified to make it more in line with the engineering practice. The proposed model has the advantages of less model parameters, wide applicability and high utilization of experimental data, and can comprehensively reflect the influence of loading method, loading time and average stress. Finally, the model was used to predict the fatigue-creep life of GH4133 superalloy under different temperature and strain ratio (stress ratio) for the experimental data and the roulette. The predicted results are in good agreement with the measured results and the accuracy is better than GSEDF model, SWT model, strain energy frequency correction method and plastic strain energy density method.