User:Eas4200c.f08.wiki.d/HW2

Within aircrafts, stringers, or longerons, are fastened inside the skin to resist the forces and moments that the fuselage and wings are subjected to during flight. In order to minimize the weight of the stringers while still providing the required structural properties, open-channel cross sections are used rather than solid ones because of there higher resistance to bending stress.

In order to demonstrate the increase in bending resistance by using open channel stringers, the moments of inertia of two stringers with different cross sections are compared below. In Case 1 a closed, solid, circular cross section is used, where as in Case 2 an open-channel cross section with the same area as Case 1 is examined.



Thus, the open-channel cross section stringer is about 11 1/2 times stronger the closed, solid, circular cross section one with the same area. As a result, a smaller,lighter stringer can be used to support the required load if the open-channel cross section is used.