We have thus far looked at In-plane loads torsional loads In addition, structures can carry loads by bending. The 2-D case is a plate, the simple 1-d case is a beam. Let's first review what you learned in Unified as Simple Beam Theory
Before we look specifically at thin-walled sections, let us consider the general case (i.e, thick-Walled) Hollow thick-walled sections Figure 12.1 Representation of a general thick-walled cross-section 中=c2 on one boundary φ=c1 on one boundary This has more than one boundary(multiply-connected do=0 on each boundary
Need to study structural mechanics to design properly to prevent failure There is no doubt that any of the disciplines of Aeronautics and Astronautics can contribute to an accident -engine failure -etc. But, the vast majority of non-human induced accidents is due to structural