Abstract:
The growth in the number of terrorist attacks and accidental explosive events imposed
additional demand on post-blast investigation tools. Numerous research addressed the
chemical analysis of explosive residuals. Yet, limited work in the literature adhered to
quantifying the blast load depending on the existing structural damage. The structural
damage assessment is a useful data collection procedure for the post-blast analysis. This
research proposes an Inverse approach that can estimate the explosive charge weight
based on analyzing post-blast structural damage. The newly proposed approach is based
on iterative finite element (FE) analysis-using Abaqus commercial package- and
involves digital image processing techniques built-in Matlab software. Furthermore, to
effectively identify the size of the blast, the genetic algorithm (GA) is used for
optimization. At the end of each iteration, the damage contour plot is exported from
Abaqus odb file through a python script. Afterward, the binary version of both the
actual damage image and the FE damage plot is investigated and compared with the aim
to minimize the difference between the real state and finite element solution. The image
analysis is performed by virtue of edge detection operators available in Matlab. Image
comparison is done depending on the Complex Wavelet- Structural Similarity Index
(CW-SSIM). The concrete behavior under blast loading is represented using the
Johnson- Holmquist-2 (Jh-2) damage constitutive material model. Likewise, the blast
load effect is described through the Conventional Weapons Effects Blast Loading
(CONWEP) model. Finally, the approach is validated using two toy examples starting
with a forward FE solution as being the real damage state. The framework was able to
predict the detonation mass with an accuracy between 97 to 99%.
