考虑加载次序影响的改进M-H模型

AN IMPROVED M-H MODEL CONSIDERING LOADING SEQUENCE EFFECT

  • 摘要: 传统的M-H模型不能考虑加载次序对后续疲劳累积损伤模型的影响,目前考虑加载次序对模型影响的改进M-H模型大多通过修改寿命比特征指数实现,可推广性受限。为此,文中建议了一种更易推广的考虑加载次序影响的方式,即等效循环比,进而给出了改进M-H模型的一般形式;并建议了可实用的等效循环比表达式,提出了一种新的改进M-H模型。借助已有试验数据验证了建议的改进M-H模型的准确性,且通过与现有模型的对比体现了文中模型的较优精度与广泛适用性。

     

    Abstract: The traditional M-H model cannot consider loading sequence effect, and in most of the improved M-H models, one parameter of traditional M-H model, namely the life ratio characteristic exponent, is modified to consider the effect of loading sequence. Naturally, the generalizability of this modification is limited. In this paper, a more generalized framework for considering loading sequence effect by the equivalent cycle ratio is presented for improving the M-H model. Further, based on a feasible formula of the equivalent cycle ratio, a new and practical improved M-H model is proposed. The accuracy of the proposed model is verified by existing experimental data, and better accuracy and wider applicability of the proposed model are demonstrated through a comparison with the existing models.

     

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