论文部分内容阅读
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。
Aiming at the traditional time reversal (TR) method to eliminate Lamb wave propagation time and complicated operation, a virtual time reversal (VTR) method is proposed. This approach uses a change-in stimulus and a receive mechanism to preserve time information and uses signal operations instead of physical TR operations. The realization process of VTR based on step excitation to acquire damage monitoring path transfer function is discussed. A high resolution damage imaging method based on VTR is proposed. In order to reduce the effect of the anisotropy of the composite material, speed correction was performed in the imaging. The experimental results show that the VTR method can partially recombine and TR focus the scattered wave packet of Lamb wave in carbon fiber composite plate, and single and two adjacent neighbors can be clearly identified by the imaging method in this paper.