Detection Of Cavities By An Inverse Elastostatics Boundary Element Method: Experimental Results

An inverse elastostatics boundary element approach is developed for the nondestructive detection of subsurface cavities in structures. The method relies on the overspecification of the boundary conditions at the exposed surface. The traction is specified there, and displacements are used as additional data for solving the inverse problem. These displacements are experimentally determined by the laser speckle photography technique. An iterative process is used to locate the cavity by driving surface residuals to zero. Iterative updates of the cavity geometry are kept within a physically realistic feasible region using an anchored grid pattern. The detection of a circular hole is presented