Development of an Efficient Finite Element Model for the Analysis of Buckling, Debonding, and Collapse Characteristics of Composite-Stiffened Panels Under Compressive Loading

A finite element model (FEM) is developed in the commercial software ANSYS© to study the buckling, debonding, and collapse behavior of composite-stiffened panels under uniaxial compression. The main goal of the developed model is to explore, without sacrificing any accuracy of the results, the possibility to overcome the required extremely fine meshes, which are followed by large computation times, when traditional cohesive zone modeling (CZM) is used, for the study of debonded structures. An engineering method from the literature that leads to significantly coarser CZM meshes, as it is proven for simple coupons only, is extended to larger scale structures (stiffened panels). Additionally, progressive damage modeling (PDM) routines are employed to the FEM of the stiffened panel to capture its overall behavior. Eventually, by modifying certain CZ model parameters, a time-efficient yet accurate FE model is obtained with PDM capabilities. This work can provide guidelines for the numerical analyses of even larger and complicated damaged structures.