Approximate computational model for the local postbuckling of omega‐stringer‐stiffened composite panels

Typical thin‐walled structures are found in applications like aircraft, spacecraft and marine vessels. For this type of structure, stability behaviour is crucial. The better this behaviour is understood, the better the full lightweight potential can be exploited. For composite structures especially, new fast analysis tools for preliminary design are required to address this issue. Therefore, the local postbuckling of omega‐stringer‐stiffened composite panels is the subject of a new computational model. The analysis method is computationally highly efficient because it is based on a closed‐form analytical approach. The explicit solution is derived based on the principle of the minimum of the total elastic potential. Furthermore, the solution assumes that the initial eigenform does not substantially change in the early postbuckling regime. In this way, the plates of the skin and stringer can be included explicitly in the analysis. Compared to finite element analysis and a closed‐form computational model found in the literature, the new analysis tool is assessed. The results indicate excellent agreement for panels, where the bay plate is the most critical element of the panel. The new computational model promises to be a highly efficient tool in the preliminary design framework.