Global/local postbuckling failure analysis of composite stringer/skin panels

A finite element methodology for postbuckling failure analysis of composite stringer/skin panels is presented, The methodology employs a global two-dimensional plate finite element model for representing overall panel deformation and a local three-dimensional solid finite element model for representing stress within a critical panel region. Global and local models are connected with a two-dimensional/three-dimensional coupling methodology that is based on multipoint constraints. Analyses are carried out for two different panel designs utilizing both linear and nonlinear material models. Computational results for failure load, failure location, and failure mode compare favorably with results from earlier experimental test programs. The findings suggest that failure initiation in postbuckled composite stringer/skin panels can be effectively modeled with the developed finite element methodology.