Reliable and practicable analysis methods for the postbuckling behaviour of thin composite plates and shells with longitudinal stiffeners under complex loading conditions

• Applicant: Professor Dr.-Ing. Christian Mittelstedt
• Subject Area: Mechanics ; Lightweight Construction, Textile Technology
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 399128978

In many technical applications in which thin-walled structures in the form of stiffened plates and shells are employed (i.e. aeronautics and astronautics, marine engineering, civil engineering, and general lightweight engineering), the last decades have seen a revolutionary shift from traditional metallic structures to the application of composite materials, e.g. in the form of fiber reinforced plastics. Very often, composite structures are being applied in the form of thin layered structures, so-called laminates. Quite naturally, due to their thin-walled nature the analysis and design of such laminated composite structures requires an in-depth analysis of their stability behavior where the investigation of the stability behavior of composite materials is still a rather new field where a good number of open questions still exists the investigation of which is the focus of the present research proposal. For plates and shells with various stiffening patters (using open-profile and close-profile stiffeners) and boundary conditions under uniaxial and biaxial compressive load, shear load, transverse pressure and the combinations thereof, closed-form analytical and semi-analytical analysis methods for the assessment of the buckling and postbuckling behavior shall be developed, based on adequate formulations for the buckling and postbuckling modes in conjunction with the Ritz-method.

• DFG Programme: Research Grants