Postbuckling of composite-structures

Purpose and goal

The overall aim of the project was to improve the competence of SAAB and FOI within the field of post buckling. The results achieved have provided SAAB and FOI with entirely new conditions for applying and further developing the framework for analysis of post-buckling composite structures developed within WP1-3. This consequently improves SAAB´s ability to design lightweight and cost effective composite structures. Hence, the previously identified technology gap at SAAB has been significantly reduced. The project has also further developed the network between SAAB and FOI.

Results and expected effects

The software package developed within WP2, which forms the core of the achievements within POSCOS, will be a valuable tool in further studies of the structures in which post-buckling is allowed. In the near term, the tool will be ideal for applications in the research programs Clean Sky and GF Demo. GF Demo aims to demonstrate new concepts for cargo doors with reduced weight where post-buckling can be permitted. Furthermore, SAAB participates regularly in concept studies with Airbus and Boeing, for which this methodology can make a contribution and strengthen SAAB´s business case.

Approach and implementation

The initial phase of the project consisted in a literature survey of previous research projects. This included the identification of state-of-the-art analytical methods (program TEW). In order to guide the study a design space for analysis was defined, and also two associated demonstrators. The corresponding test specimens were manufactured. Work on WP1-4 proved to be of a somewhat more iterative nature than assumed. Also, the complexity and volume of work within WP1 was underestimated. This led to a request for a six month extension, to complete the analysis and testing.