GLOBAL LOCAL POSTBUCKLING FAILURE ANALYSIS OF COMPOSITE STRINGER/SKINPANELS/

A finite element methodology for postbuckling failure analysis of comp osite stringer/skin panels is presented, The methodology employs a glo bal two-dimensional plate finite element model for representing overal l 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-dimensiona l coupling methodology that is based on multipoint constraints. Analys es are carried out for two different panel designs utilizing both line ar and nonlinear material models. Computational results for failure lo ad, failure location, and failure mode compare favorably with results from earlier experimental test programs. The findings suggest that fai lure initiation in postbuckled composite stringer/skin panels can be e ffectively modeled with the developed finite element methodology.