基于激光超声的钛合金裂纹合成孔径组合成像研究
Synthetic aperture combination imaging of cracks in titanium alloy based on laser ultrasonics
陈涛 1张洪伟 1闫锡超 1袁俊2
作者信息
- 1. 北京石油化工学院,机械工程学院,北京 102617
- 2. 北京翔博科技股份有限公司,北京 101312
- 折叠
摘要
针对钛合金内部疲劳裂纹激光超声成像问题,提出了一种基于合成孔径聚焦技术的多模式组合成像方法.采用扫描激光源法,通过提取不同探测位置的时域模式回波信号,根据B-scan图中反射纵波与反射横波的幅值分布,将裂纹回波时域特征进行分区重组,对其进行反演聚焦完成了对内部裂纹的识别及图像重构.使用COMSOL Multiphysics对钛合金板材内部裂纹成像过程进行数值模拟并通过MATLAB图像算法验证了其可行性.与单一模式波成像相比,采用反射纵波与反射横波组合的成像方法有效减少了伪像,实现了对内部裂纹的定位及图像重构,重构裂纹位置X轴与Y轴相对误差均在3％以内.
Abstract
In this paper,a multi-modal combination imaging method based on synthetic aperture focusing technique is proposed to address the laser ultrasonic imaging problem of internal fatigue cracks in titanium alloy.The scanning la-ser source method is employed to extract time-domain mode-echo signals from different detection positions.By analy-zing the amplitude distribution of reflected longitudinal waves and reflected shear waves in the B-scan image,the tem-poral characteristics of crack echo signals are partitioned and recombined.Furthermore,inversion focusing is applied to accomplish the recognition and image reconstruction of internal cracks.The feasibility of this approach is demon-strated by conducting numerical simulations of the internal crack imaging process in titanium alloy plates using COM-SOL Multiphysics,and its viability is further validated using MATLAB image algorithms.Compared to single-mode wave imaging,the imaging method that combines reflected longitudinal wave and reflected shear waves effectively re-duces artifacts,enabling accurate localization and image reconstruction of internal cracks.The relative errors of the re-constructed crack positions in the X-axis and Y-axis are both within 3％.
关键词
合成孔径聚焦技术/钛合金/方向性/内部裂纹Key words
SAFT/titanium alloy/directivity/internal cracks引用本文复制引用
基金项目
北京市高等学校高精尖学科建设机械工程项目(21010221002)
国家级大学生创新创业训练计划(2022J00180)
出版年
2024
NETL
NSTL
万方数据