0128 Detection of Back Surface Cracks by Self-Reference Lock-in Thermography

Izumi, Yoshiharu; Sakagami, Takahide; Kubo, Shiro; Tamakoshi, Takashi; Ishio, Mari

doi:10.1299/jsmemm.2008._0128-1_

Cited by 1 publication

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The present authors developed a self-reference lock-in thermography [3], which does not require any external reference signals and can be employed even under random loading. Nondestructive inspections of fatigue cracks in steel bridges were conducted by the proposed selfreference lock-in thermography in the previous paper [4]. In this paper, detection of through-deck type fatigue cracks in a steel deck specimen is conducted by the self-reference lock-in thermography.…”

Section: Introductionmentioning

confidence: 99%

Detection of Through-Deck Type Fatigue Cracks in Steel Bridges by Self-Reference Lock-in Thermography

Izumi

Sakagami

Kubo

et al. 2010

EPJ Web of Conferences

View full text Add to dashboard Cite

Abstract.A new remote nondestructive inspection technique, based on thermoelastic temperature measurement by infrared thermography, is developed for detection and evaluation of fatigue cracks propagating from welded joints in steel bridges. Fatigue cracks are detected from localized high thermoelastic temperature change at crack tips due to stress singularity under variable loading from traffics on the bridge. Selfreference lock-in data processing technique is developed for the improvement of signal/noise ratio in the crack detection process. The technique makes it possible to perform correlation processing without an external reference signal. It is very difficult to detect through-deck type fatigue cracks in steel decks by the conventional NDT technique, since they are not open to the inspection. In this paper, self-reference lock-in thermography is applied for detection of through-deck type fatigue cracks. Experiments are carried out to steel deck sample, which simulates an actual steel bridge, during crack propagation test. It is found that significant stress concentration zone can be observed near the crack front, which enabled us to detect through-deck type fatigue cracks and to estimate its size.

show abstract

Section: Introductionmentioning

confidence: 99%