Abstract Fatigue design assessment is a crucial step in the design process of ships and offshore structures. To date, the stochastic approach is commonly used to calculate the total lifetime accumulated fatigue damage and the probability of fatigue failure for the structures. Meanwhile, the details of damage initiation and propagation are infrequently investigated. In terms of predicting crack growth, the traditional approaches face conceptual and mathematical difficulties in terms of predicting crack nucleation and growth, especially for multiple crack paths because the equations in classical continuum mechanics are derived by using spatial derivatives. Peridynamics is a non-local theory using the integral equations rather than differential equations which makes it suitable for damage prediction. In this study, a novel energy-based peridynamic model for fatigue cracking is proposed. The definition of cyclic bond energy release rate range and the energy-based peridynamic fatigue equations for both phases crack initiation and crack growth phases are introduced. For validation, first, a problem of mode-I fatigue crack growth is investigated. Next, different mixed-mode fatigue damages are also investigated and the peridynamic results are compared with the experimental results.

中文翻译：

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基于能量的疲劳开裂近场动力学模型

摘要 疲劳设计评估是船舶和海上结构设计过程中的关键步骤。迄今为止，随机方法通常用于计算结构的总寿命累积疲劳损伤和疲劳失效概率。同时，很少研究损伤引发和传播的细节。在预测裂纹扩展方面，传统方法在预测裂纹成核和扩展方面面临概念和数学上的困难，尤其是对于多裂纹路径，因为经典连续介质力学中的方程是通过使用空间导数推导出来的。近场动力学是一种使用积分方程而不是微分方程的非局部理论，这使其适用于损伤预测。在这项研究中，提出了一种新的基于能量的疲劳开裂近场动力学模型。介绍了循环键能释放率范围的定义以及裂纹萌生和裂纹扩展阶段的基于能量的近场动力学疲劳方程。为了验证，首先研究了 I 型疲劳裂纹扩展问题。接下来，还研究了不同的混合模式疲劳损伤，并将近场动力学结果与实验结果进行了比较。