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为研究筋条截面形式和多部位损伤对整体加筋板裂纹偏转行为和断裂特性的影响,采用断裂力学和有限元方法对其进行分析.首先建立整体加筋板疲劳裂纹扩展模型,通过与裂纹扩展速率试验进行比较验证模型可靠性;在此基础上讨论筋条截面形式对裂纹断裂参量和转折行为的影响;最后对多裂纹问题进行研究.结果表明:筋条截面形式对断裂参量的影响并不显著,裂纹偏转行为在远离筋条区域扩展时发生的可能性最大;多裂纹情况下裂纹并不会转折,而是笔直扩展进而连通成一条大裂纹,同时由于相邻裂尖的强烈干涉,造成应力强度因子剧增,加速裂纹扩展,进而严重缩短了扩展寿命,因此需采用有效的修补手段来提高结构的剩余强度和使用寿命.
In order to study the effect of section and multi-site damage on the crack deflection behavior and fracture characteristics of the whole stiffened plate, the fracture mechanics and finite element method are used to analyze the model.Firstly, the fatigue crack growth model of the stiffened plate is established, And the extended rate test to verify the reliability of the model.On this basis, the influence of the cross-section of the bars on the fracture parameters and the transition behavior of the crack is discussed.Finally, the multi-crack problem is studied.The results show that the influence of the cross-section of the bars on the fracture parameters The cracks are most likely to occur when they extend away from the rib area. In the case of multi-crack, the crack will not turn, but the straight crack expands and becomes a large crack. At the same time, due to the strong interference of the adjacent crack tip, As a result, the stress intensity factor increases sharply and accelerates the crack growth. As a result, the service life is greatly shortened. Therefore, an effective repair method is needed to improve the residual strength and service life of the structure.