In this lecture Prof. C. Kassapoglou covers the results of the Euler-Lagrange equation, which were constructed in the previous lecture, followed by sandwich structures.

The lecture takes off with a discussion of the methods that were used to solve the second assignment, after which the final steps of the Euler-Lagrange solutions are derived. A thorough discussion of the results then follows, where different parts of the solution are analyzed and compared with different solution methods to draw conclusions about the design of stiffened panels and the validity of the method.

The second part of the lecture covers sandwich structures, ranging from the theoretical function to practical implications. This subject is concluded with a discussion of the different failure modes that exist for sandwich structures.