Optimal Detection of Crack Echo Families in Elastic Solids
2003 (English)In: The Journal of the Acoustical Society of America, Vol. 113, no 5, 2732-2741 p.Article in journal (Refereed) Published
Optimal detection of a striplike crack residing in an isotropic elastic solid with coarse microstructure by means of ultrasonic nondestructive evaluation (NDE) is considered. A physics-based approach to derive an optimal detector, which achieves the theoretical limitations constrained by the underlying physics, is presented. State-of-the-art physical models of crack echoes and of stochastic backscattering from the material structure in elastic solids are introduced and unified with the theory of optimal detection to yield a practically useful nonlinear filter bank implementation of the optimal detector. Monte Carlo simulations of the detection performance for the special case of a striplike crack with uncertain angular orientation are presented in the form of receiver operating characteristics (ROCs). These new results represent the physical limitations for detecting a crack under the stated conditions and serve as performance bounds to which other detectors should be compared. A physics-based generalized likelihood ratio (GLR) detector, which relies on the same nonlinear filter bank as the optimal detector, is also presented for the special case of a striplike crack. A comparison between the optimal and the GLR detectors shows that the GLR detector only slightly reduces the performance.
Place, publisher, year, edition, pages
2003. Vol. 113, no 5, 2732-2741 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-90175PubMedID: 12765391OAI: oai:DiVA.org:uu-90175DiVA: diva2:162438