The curved composite structures are popularly used in the aerospace field for their superior properties. Complexity of structure and geometry generally limit the inspection or monitoring effect of different types of defects in the curved composite structure. A feasible damage probabilistic tomography algorithm combined with ultrasonic guided wave technology is necessary to be developed for the structural health monitoring of curved composite structures. In this paper, defect zones in a curved composite structure are characterized using the modified probabilistic tomography (MPT) method and fusion of damage index (DI). The MPT with the defect shape factor ${\beta }_M$ at each damage-impaired path and hybrid DI schemes are proposed to indicate the location and propagation of defect zones in tested sample. The feasibility of proposed approaches is verified on the curved carbon/epoxy composite structure, experimentally. The results show that the MPT and fusion DI methods successfully represent the extension of defect zones in a quantitative manner. It is suggested that the accuracy and reliability of localization results of the MPT algorithm is better than those obtained by the probabilistic tomography (PT) algorithm with the averaged $\beta$.

弯曲的复合结构因其优异的性能而广泛用于航空航天领域。结构和几何形状的复杂性通常限制了弯曲复合结构中不同类型缺陷的检查或监视效果。对于弯曲复合结构的结构健康监测，有必要结合超声导波技术，提出一种可行的损伤概率层析成像算法。在本文中，使用改进的概率层析成像（MPT）方法和损伤指数（DI）融合来表征弯曲复合结构中的缺陷区域。具有缺陷形状因数的MPT${\beta }_{\mathrm{中号}}$在每个损伤受损的路径上，提出了混合DI方案以指示测试样品中缺陷区域的位置和传播。实验证明了该方法的可行性。结果表明，MPT和融合DI方法成功地代表了缺陷区域的定量扩展。提出MPT算法定位结果的准确性和可靠性优于概率层析成像（PT）算法得到的结果的准确性和可靠性。$\beta$。