Nondestructive Testing of Polymeric Composite Sandwich Panels Via the Thermographic Halo

摘要

A two dimensional thermogmphic nondestructive testing (NDT) model of a polymeric composite sandwich panel containing a planar discontinuity within its core is presented and the model's surface temperature distributions in the discontinuity's thermographic transition zone are obtained via the finite element method. A characteristic length of the surface temperature transition zone is defined for discontinuities that can be modeled as semiinfinitely long. The effect on the characteristic length of varying the geometrical and thermal discontinuity parameters is investigated numerically. Thermographic NDT procedures are devised to characterize the geometrical and thermal parameters of the discontinuity.