摘要
针对传统时间反转(TR)方法消除Lamb波传播时间和操作复杂的问题,提出了虚拟时间反转(VTR)方法。该方法采用换元激励和接收机制以保留时间信息,并运用信号运算代替物理TR操作。讨论了基于阶跃激励获取损伤监测路径传递函数的VTR实现过程。提出了基于VTR的高分辨率损伤成像方法。为了降低复合材料各向异性的影响,在成像中进行了速度修正。实验结果表明,VTR方法能对碳纤维复合材料板中的Lamb波损伤散射波包进行部分再压缩和TR聚焦,通过本文中成像方法也能清晰显示出板中单个和两个近邻损伤。
According to the problems that traditional time reversal （TR） method eliminates propagation time of Lamb waves and its procedure is complieated, a virtual time reversal （VTR） method is presented. In the method, changing-element exciting and receiving mechanism is adopted to reserve time information and the TR procedure is replaced by the signal operations. The realization involving acquiring transfer functions of damage detecting path under step pulse excitation is discussed. A high-resolution damage imaging method based on VTR is developed. To reduce the anisotropic effect in composite plates, velocity correction is carried out during the imaging. The experimental results show that damage scattered wavepaekets of Lamb waves in the carbon fiber composite plate can be partly recompressed and time reversal focused by VTR. Both the signal damage and dual adjacent ones in the plate are clearly displayed by the proposed imaging method.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2012年第1期183-189,共7页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(10872217)
国家自然科学基金重点项目(50830201)
国家高技术研究发展计划(863)(2007AA03Z117)
航空科学基金(20090952015)
