聚乙烯(PE)结构在制备和服役过程中,其内部可能出现埋深缺陷,严重时结构完整性会受到影响甚至结构失效,因此对PE结构埋深缺陷实施有效无损定量检测至关重要。聚焦于PE结构的无损检测,探究PE结构背面减薄缺陷和内部夹杂缺陷的微波可视化检测,提出基于奇异值分解(SVD)的直达波抑制算法以实现高精度缺陷成像。同时,综合分析比较了双脊波导、矩形波导两种微波探头在PE结构埋深缺陷定量检测中的优劣,明确了所提微波检测信号特征和直达波抑制算法在PE结构埋深缺陷可视化定量检测中的有效性和优势性。

Polyethylene (PE) structures, which poses a severe threat to structure integrity and would lead to structural failure. Therefore, it is imperative to detect and assess the buried defects in PE structures through effective nondestructive evaluation techniques. In this paper, microwave testing and imaging of the back-surface defect and inclusion in PE structures were intensively investigated. A direct-wave suppression algorithm based on singular value decomposition (SVD) was proposed for production of high-precision microwave images of defects. In parallel, two microwave probes i.e., the double-ridged waveguide and rectangular waveguide were compared in regard to quantitative evaluation of defects hidden within PE structures. The applicability as well as the superiority of the proposed signal feature of the microwave testing signal and SVD based direct-wave suppression algorithm for imaging and assessment of buried defects in PE structures was identified.