Abstract
A typical pulsed thermography procedure results in a sequence of infrared images that reflects the evolution of temperature over time. Many features of defects, such as shape, position, and size, are derived from single image by image processing. Hence, determining the key frame from the sequence is an important problem to be solved first. A maximum standard deviation of the sensitive region method was proposed, which can identify a reasonable image frame automatically from an infrared image sequence; then, a stratagem of image composition was applied for enhancing the detection of deep defects in the key frame. Blob analysis had been adopted to acquire general information of defects such as their distributions and total number of defects. A region of interest of the defect was automatically located by its key frame combined with blob analysis. The defect information was obtained through image segmentation techniques. To obtain a robustness of results, a method of two steps of detection was proposed. The specimen of polyvinyl chloride with two artificial defects at different depths as an example was used to demonstrate how to operate the proposed method for an accurate result. At last, the proposed method was successfully adopted to examine the damage of carbon fiber-reinforced polymer. A comparative study between the proposed method and several state-of-the-art ones shows that the former is accurate and reliable and may provide a more useful and reliable tool for quality assurance in the industrial and manufacturing sectors.
Highlights
The health monitoring of materials and structures plays a vital role in the fields of aerospace, industry, medical, and construction [1,2]
Each composition image was synthesized by 10 random frames experiment were randomly selected, too
We developed an effective approach to accurately detect defects with different depths on a polyvinyl chloride (PVC) specimen
Summary
The health monitoring of materials and structures plays a vital role in the fields of aerospace, industry, medical, and construction [1,2]. Even minor material defects may cause major hidden danger. Nondestructive testing (NDT) technology provides a strong technical guarantee for the safety of material structure. As a new nondestructive testing technology, pulsed thermal nondestructive testing (TNDT) is widely used in the detection of defects in materials and structures due to its large detection area, fast detection speed, detection convenience, and cheap equipment [3]. Researchers can obtain the continuous change process of the transient temperature field on the material surface through the infrared thermal imager. A sequence of infrared images expresses the evolution of temperature intuitively. The method of digital image processing is applied to assess
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
