TY - GEN
T1 - Nonlinear ultrasonic phased array imaging of closed cracks using global preheating and local cooling
AU - Ohara, Yoshikazu
AU - Takahashi, Koji
AU - Ino, Yoshihiro
AU - Yamanaka, Kazushi
PY - 2015/10/28
Y1 - 2015/10/28
N2 - Closed cracks are the main cause of underestimation in ultrasonic inspection, because the ultrasound transmits through the crack. Specifically, the measurement of closed-crack depth in coarse-grained materials, which are highly attenuative due to linear scatterings at the grains, is the most difficult issue. To solve this problem, we have developed a temporary crack opening method, global preheating and local cooling (GPLC), using tensile thermal stress, and a high-selectivity imaging method, load difference phased array (LDPA), based on the subtraction of phased array images between different stresses. To demonstrate our developed method, we formed a closed fatigue crack in coarse-grained stainless steel (SUS316L) specimen. As a result of applying it to the specimen, the high-selectivity imaging performance was successfully demonstrated. This will be useful in improving the measurement accuracy of closed-crack depths in coarse-grained material.
AB - Closed cracks are the main cause of underestimation in ultrasonic inspection, because the ultrasound transmits through the crack. Specifically, the measurement of closed-crack depth in coarse-grained materials, which are highly attenuative due to linear scatterings at the grains, is the most difficult issue. To solve this problem, we have developed a temporary crack opening method, global preheating and local cooling (GPLC), using tensile thermal stress, and a high-selectivity imaging method, load difference phased array (LDPA), based on the subtraction of phased array images between different stresses. To demonstrate our developed method, we formed a closed fatigue crack in coarse-grained stainless steel (SUS316L) specimen. As a result of applying it to the specimen, the high-selectivity imaging performance was successfully demonstrated. This will be useful in improving the measurement accuracy of closed-crack depths in coarse-grained material.
UR - http://www.scopus.com/inward/record.url?scp=84984569939&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84984569939&partnerID=8YFLogxK
U2 - 10.1063/1.4934455
DO - 10.1063/1.4934455
M3 - Conference contribution
AN - SCOPUS:84984569939
T3 - AIP Conference Proceedings
BT - Recent Developments in Nonlinear Acoustics
A2 - Sparrow, Victor W.
A2 - Dragna, Didier
A2 - Blanc-Benon, Philippe
PB - American Institute of Physics Inc.
T2 - 20th International Symposium on Nonlinear Acoustics, ISNA 2015, including the 2nd International Sonic Boom Forum, ISBF 2015
Y2 - 29 June 2015 through 3 July 2015
ER -