Chap.5 Load Transfer in Stiffened Panel Structure • Point loads acting on idealized wing and fuselage str. can not be applied directly to the shear panels. • Shear panels – capable of supporting only pure shear exerted in their plane. • Stiffeners – direct loads are applied to the stiffeners. → the loads are diffused to the shear panels. Wing- rib Fuselage – frame Semimonocoque structures → shear panels + stiffeners

Chap.5 Load Transfer in Stiffened Panel Structure ① load transfer 개념 해석 ② cutout 이 있는 경우의 해석 Statically determinate – Fig. 5. 1. 2 (treated as a truss) Statically indeterminate – Fig. 5. 1. 1 (Chapter.7) Semimonocoque structures 5.2 Rib and Bulk head Shear Flow. Jump in the shear flow

The change in between 1 and 2 along the bond line (5.2.2) : positive if it acts (negative y-direction) : positive if acts in the negative z-direction. • interface shear flow the loads applied directly to the stiffener remind identical

(4.8.2) (4.8.3) : jump in the flange load gradient across a stiffener for longitudinal stiffeners where

Example (Load gradient)

Example 5.2.1 Ring stiffener No longitudinal stiffeners • shear flow on the ring stiffener depends only on the loads applied directly to the stiffener

Example 5.2.2 Panel shear flows in each of the two bays adjacent to section C The shear flow around the perimeter of frame C Stringer areas (a) Load gradients

Between B and C Between the section C and D

Aft of section C Shear flows in the bay immediately ahead of section C

(b) At section C Check

Example 5.2.3 Calculate the shear flow distribution around the frame.

Example 5.2.4 Calculate the average shear flow in each of the four rib webs and the axial loads in the rib flanges at the location just to the right of the vertical stiffeners ef, cd, and ab Figure 5.2.17 Wing box rib with a point load applied to the leftmost vertical stiffener

Figure 5.2.17 Wing box rib with a point load applied to the leftmost vertical stiffener Eq. 2.5.4