Fatigue behavior of damaged steel beams repaired with CFRP strips
Fatigue behavior of damaged steel beams repaired with CFRP strips
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DOI：
10.1016/j.engstruct.2011.01.019
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发表时间：
2011-05
影响因子：
5.5
通讯作者：
Y. J. Kim;K. Harries
中科院分区：
文献类型：
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作者：
Y. J. Kim;K. Harries
研究了碳纤维布加固损伤钢梁的抗弯性能。损坏是通过在梁的张力凸缘上开槽而故意造成的。通过对6根加固梁的静力和疲劳性能的试验研究，重点分析了加固梁的局部塑性和CFRP-钢界面的力学性能。一个三维有限元分析（FEA）进行预测的实验行为。基于应变寿命法和累积损伤理论，提出了一种模拟修复梁疲劳响应的建模方法。CFRP加固后，损伤梁的静承载力恢复到未损伤梁的水平。损伤处的应力范围影响修复梁的疲劳寿命、损伤扩展和塑性应变发展。裂纹在梁腹板上的扩展在其疲劳寿命的50%以下并不显著，而脆性腹板断裂则在超过阈值之后发生。在CFRP-钢界面处观察到双线性疲劳响应，其幅度取决于疲劳循环次数和施加的应力范围。提出了一个经验模型来预测界面的疲劳行为。
This paper presents the flexural behavior of damaged steel beams repaired with carbon fiber reinforced polymer (CFRP) strips. The damage is intentionally created by notching the tension flange of the beams. Six beams are tested to evaluate the static and fatigue performance of the repaired beams with emphasis on local plasticity and the CFRP–steel interface. A three-dimensional finite element analysis (FEA) is conducted to predict the experimental behavior. A modeling approach is proposed to simulate the fatigue response of the repaired beams, based on the strain-life method and cumulative damage theory. CFRP-repair results in a recovery of static load-carrying capacity of the damaged beam to that of an undamaged beam. The stress range at the damage influences the fatigue life, damage propagation, and plastic strain development of the repaired beams. Fatigue-crack propagation across the web of the beams is not significant up to 50% of their fatigue life, whereas brittle web fracture follows beyond the threshold. A bilinear fatigue response is observed at the CFRP-steel interface, whose magnitudes are dependent upon the number of fatigue cycles and the applied stress range. An empirical model is proposed to predict the fatigue behavior of the interface.