桥梁缆索金属损伤无损检测方法

缆索广泛应用于斜拉桥、悬索桥和拱形桥等桥梁结构中,其有效金属承载面积直接关系到桥梁安全。在分析桥梁缆索自身结构和使用工况的基础上,论述了桥梁缆索无损检测中遇到的难点,分析了可能应用于桥梁缆索金属损伤的无损检测方法的特点和局限性,其中声发射法可用于缆索的长期监测,但仅能给出相对检测结果;射线法和磁性检测法可用于缆索的逐点扫描检测,但检测移动辅助装置复杂;磁致伸缩导波检测方法可实现远距离的包括锚固区在内的金属损伤检测,但信号解释复杂。最后,提出了桥梁缆索磁致伸缩导波快速扫查和磁性精细扫查相结合的无盲区检测方法,该研究将促进桥梁缆索无损检测技术的深入发展。

Nondestructive Testing Method for Metallic Flaws of Bridge Cables

Cables and wire ropes are mostly employed in the structure of cable-stayed bridges, suspension bridges and arch bridge. Its effective metallic loading area determines the safety of the bridge. Based on the analysis of the bridge cable structure and its working condition, main problems in nondestructive testing of bridge cables are described in this paper. Then, the possible method for NDT of bridge cables including their characteristics and limits are given. The acoustic emission testing method can be used in the cable on-line condition and only can give relative results of different cable conditions. The radiography and magnetic testing methods can scan along the cable, but the complicated auxiliary apparatus is required. The magnetostrictive guided wave testing method can detect far flaws of cables, which include the anchorage zone, but its signal interpretation requires complex knowledge. In the last, a blind zone free NDT method for the bridge cable which is to combine rapid scanning and magnetic precise testing together is proposed. The above research work will advance further development of nondestructive testing technique for the bridge cables.