2006 Volume 13 Issue 51 Pages 49-60
Thin steel plates, which have initial cracks at the center, are used as "the Sacrificial Test Pieces" in this study. The purpose is to investigate the practical applicability of the Sacrificial Test Piece for estimation of the fatigue damage parameter on bridge members and remote measurement of crack length by the self reference lock-in thermography. Main results are summarized as follows. 1) The fatigue damage parameter can be estimated by the Sacrificial Test Piece by the accuracy within 15% under fluctuating amplitude loads measured in highway bridge, although the delay and acceleration of the crack propagation are observed under fluctuating amplitude loads. 2) It is suggested that the crack length of the Sacrificial Test Piece can be measured from a long distance by the self-reference lock-in thermography.