Li Anbang, Wang Hao, Li Han, Kong Deliang, Xu Shanhua
School of Civil Engineering, Xi'an University of Architecture & Technology, Xi'an 710055, China.
State Key Laboratory of Green Building in Western China, Xi'an 710055, China.
Polymers (Basel). 2022 Sep 14;14(18):3845. doi: 10.3390/polym14183845.
The purpose of this study is to investigate the stress concentration of a corroded steel plate strengthened with carbon fiber reinforced polymer (CFRP) plates. An accelerated corrosion experiment was first executed to acquire corroded steel plates, and then surface profile measurements were conducted to obtain 3D coordinate data of the corroded steel surface. Finite element models considering the surface morphology of the corroded steel plate and the interfacial bonding properties between the CFRP plate and the corroded steel plate were established to investigate the stress concentration of the corroded steel plate strengthened with and without CFRP plates. The reliability of the numerical modeling method was verified based on a mesh convergence analysis and a comparison of the fatigue test, 3D morphology scanning, and numerical analysis results. Specimens with five levels of corrosion damage, six kinds of CFRP-strengthening stiffness, five kinds of adhesive thickness, and five levels of CFRP prestress were numerically modeled. The primary indications consist of features of stress distribution, and the stress concentration factors and were analyzed. Results showed that the features of stress distribution and the stress concentration factor of the corroded steel plate strengthened with and without CFRP plates are only related to the shape, size, and position of rust pits, but not to the degree of uniform corrosion or the reinforcement parameters. The value of for the corroded steel plate with a corrosion duration of 618 months and a weight loss rate of 9.1621.78% was approximately 1.199~1.345. The converted stress concentration factor has more practical significance than the stress concentration factor in describing the influence of corrosion and CFRP reinforcement on the peak tensile stress of the corroded steel plate. The value of increased linearly with the increase of the weight loss rate of the corroded steel plate and decreased appreciably with the increase of the strengthening stiffness and prestress level of the CFRP plates, and it presented a very small increasing trend with the increase of the adhesive thickness.
本研究的目的是调查用碳纤维增强聚合物（CFRP）板加固的腐蚀钢板的应力集中情况。首先进行加速腐蚀试验以获取腐蚀钢板，然后进行表面轮廓测量以获得腐蚀钢表面的三维坐标数据。建立了考虑腐蚀钢板表面形态以及CFRP板与腐蚀钢板之间界面粘结性能的有限元模型，以研究有无CFRP板加固的腐蚀钢板的应力集中情况。基于网格收敛分析以及疲劳试验、三维形态扫描和数值分析结果的比较，验证了数值建模方法的可靠性。对具有五级腐蚀损伤、六种CFRP加固刚度、五种粘结剂厚度和五级CFRP预应力的试件进行了数值模拟。主要指标包括应力分布特征，并分析了应力集中系数 和 。结果表明，有无CFRP板加固的腐蚀钢板的应力分布特征和应力集中系数仅与锈坑的形状、尺寸和位置有关，而与均匀腐蚀程度或加固参数无关。腐蚀持续时间为6至18个月且重量损失率为9.16%至21.78%的腐蚀钢板的 值约为1.199至1.345。在描述腐蚀和CFRP加固对腐蚀钢板峰值拉应力的影响方面，转换后的应力集中系数 比应力集中系数 具有更实际的意义。 的值随腐蚀钢板重量损失率的增加呈线性增加，随CFRP板加固刚度和预应力水平的增加而明显降低，并且随粘结剂厚度的增加呈现非常小的增加趋势。
