10.1 Segment Stiffness


A segment is a straight line joining 2 nodes in the drawing that represents the cross section of the beam as shown in Figure 10.1.

From the material’s point of view, each segment represents a panel, also called webs and flanges. Each panel is composed of a number of laminates, each having a number of laminas. All the properties of those laminates put together into a panel are summarized by the Segment Stiffnesses, as follows:

Ai is the membrane axial stiffness of the panel/segment along the length x of the beam.

Di is the bending stiffness of the segment.

Bi is the bending-extension coupling of the segment that appears when the panel in not symmetric through its thickness.

Fi is the inplane shear stiffness of the segment.

Hi is the twisting stiffness of the segment when subjected to shear flow q. This is better explained in the textbook.

Ci is the twisting-shear coupling of the segment.

Segment stiffnesses are to panels what A, B, D, H matrices are to laminates. Laminates are analyzed in chapter Macromechanics.