NUMERICAL SIMULATION OF C-141 LOWER WING PANELS WITH AND WITHOUT SIMULATED EXFOLIATION CORROSION UNDER COMPRESSION

摘要

In-plane compression studies of full-scale integrally stiffened C-141 lower wing panels were carried out both experimentally and numerically. Two different wing panels were compressed until failure: one panel was pristine and the other had a centrally located artificial grindout simulating an aggressive removal of exfoliation or other corrosion damage. Two C-channel anti-buckling stiffeners were installed along the edges of the panels on the lower wing front/outer surface, which represented the support normally provided by the adjacent wing panels. For the numerical simulation, a three-dimensional finite element model was developed to simulate the experimental setup. Both linear Eigen-value buckling analysis and nonlinear post-buckling analysis were performed. Out-of-plane buckling deflection was observed in both the numerical post-buckling and experimental results. Full-field stress contours showed that the largest stresses were generated in the panel central section, especially for the damaged panel. The numerical post-buckling results showed that the assumed material parameters, I.e., initial yield and stress-strain curve beyond the initial yield stress, had a considerable influence on the calculated in-plane compression strength.