Title:
Nondestructive Evaluation Using Numerical Simulation of
Impact Response
Author(s):
Craig M. Newtson and Marc O. Eberhard
Publication:
Materials Journal
Volume:
97
Issue:
3
Appears on pages(s):
343-350
Keywords:
cracking (fracturing); dynamic response; nondestructive test-ing;
pavement; and slabs.
DOI:
10.14359/4627
Date:
5/1/2000
Abstract:
A new algorithm has been developed to estimate the material proper-ties and geometry of a concrete slab or pavement by comparing meas-ured and simulated dynamic responses to a surface impact. The reconstruction algorithm consists of the following steps: 1) recording an impact and the acceleration response histories at multiple locations; 2) comparing these histories with the histories computed with a finite-difference model; and 3) varying the properties of the model until the difference between measured and computed responses is minimized. The minimization identifies an optimal solution for the material and geometric properties of the slab or pavement. A parametric study determined that Young's modulus, slab thickness, crack location, and crack depth would be the easiest properties to identify because they have the most significant influence on the acceleration response of a concrete pavement. Using experimental measurements of dynamic response, the algorithm simultaneously identified the slab thickness within approximately 11% of the actual depth and the Young’s mod-ulus of the slab within 5% of comparable values obtained from labo-ratory tests. An important advantage of the numerical simulation approach is that, as computing power increases, the method can be applied to more complex systems.