Weight Critical Structures

• Account for the assumptions for first and higher order beam and plate theories for both unstiffened and stiffened layered laminates and sandwich structures.
• Formulate relevant boundary conditions for plate fields in lightweight structures.
• Perform theoretical stress and deformation analyses of unstiffened and stiffened plates in lightweight structures by use of Navier’s, Levy’s and Rayleigh-Ritz’s solution methods.
• Perform theoretical stress and deformation analyses of sandwich beams with shear deformations.
• Perform theoretical stress and deformation analyses of layered sandwich plates based on classical lamination theory and basic sandwich theory with shear deformations.
• Perform theoretical stability analysis of unstiffened and stiffened laminate and sandwich plates.
• Analyze and design cohesive joints in laminate and sandwich constructions.
• Calculate progressive failure of rectangular and laterally loaded sandwich plates using failure criteria for composite materials.
• Perform fracture mechanics analysis of typical damage scenarios for laminate and sandwich structures.
• Use a commercial FEM program to analyze and design both unstiffened and stiffened plate structures consisting of laminate and sandwich composite materials.
• Compare analytical, numerical and experimentally achieved results for a given lightweight plate structure and evaluate the quality of the respective results.
• Write a technical report containing analysis including the above mentioned points applied on a practical design example from an aircraft, ship, automotive or space vehicle.

1) Unstiffened and stiffened plates: Differential equations, stiffness behavior of stiffened plate panels, stress calculation, boundary conditions, analysis methods (Navier and Rayleigh-Ritz methods).

2) Layered sandwich beams and plates: Differential equations, stiffness properties and their connection to classic lamination theory, stress calculation, basic sandwich theory with shear deformations and first order sandwich beam and plate theories and their analysis methods.

3) Stability of composite plates: Analytical buckling analysis methods, energy method, stiffened plates, buckling of layered sandwich plates and the influence of imperfections.

4) Progressive failure analysis of laminate and layered sandwich plates.

5) Analysis and design of joints between composite plates and other structural elements.

6) Fracture mechanical analysis of typical damages in laminate and sandwich plates.

7) Design principles and practical application of analytical solutions and FEA for plate structures within typical weight critical constructions such as aircrafts, ships, automotive and space vehicles.

8) Experimental methods for plate structures consisting of composite materials.

41516/41815/41812/41958/41239/02002/02003, or similar.

Lectures and project work in groups of max. 2 students.
Throughout the course students will work with two practical design projects, which will be supported by the theoretical lectures.