This paper introduces a novel digital twin solution for unlocking the elasto-plastic fatigue crack growth within an S550 steel under negative load ratios. The digital twin transforms solely strain data from a strain-interfaced welded plate joint specimen to the load–displacement curve to compute cyclic -integral values using the approach, eliminating the need for load and displacement measurements. The accurate computation of the elasto-plastic Δ effectively extends the fatigue crack growth relationship derived from standard fracture specimens. The extended fatigue crack growth relationship accurately predicts the fatigue life of specimens under separate step-up and step-down variable amplitude loading regimes.

中文翻译：

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解锁负载荷比下弹塑性疲劳裂纹扩展速率的数字孪生方法

本文介绍了一种新颖的数字孪生解决方案，用于解锁负载荷比下 S550 钢内的弹塑性疲劳裂纹扩展。数字孪生仅将应变界面焊接板接头样本的应变数据转换为载荷-位移曲线，以使用该方法计算循环积分值，从而无需进行载荷和位移测量。弹塑性Δ的精确计算有效地扩展了从标准断裂试样导出的疲劳裂纹扩展关系。扩展的疲劳裂纹扩展关系准确地预测了单独的逐步递增和递减变幅加载状态下样本的疲劳寿命。