Resultants | ||||||||

Force and moment resultants are convenient quantities for tracking the | ||||||||

Perfect Bonding between Layers | ||||||||

For a laminated composite plate, the material properties can be quite different from layer by layer, and the stress distribution may be significantly different between layers. As a result, it is desirable to express the moment and force resultants in terms of the normal and shear stresses In lamination theory, a laminate composed of two or more laminae (usually in several different directions) acts as
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Recall that the stress tensor has nine components at any given point. Each little portion of the direct stress acting on the cross section creates a moment about the neutral plane ( M, _{y}M, and _{xy}M,
_{yx}where y direction; M is along the -_{y}x direction; M is along the -_{xy}x direction; and M is along the _{yx}y direction.
Summing the shear forces on the cross-section is the definition of the transverse shear resultants _{y},
There is one more set of force resultants that we need to define, the N, _{y}N, and _{xy}N.
_{yx}
N, _{y}N, and _{xy}N are the total in-plane normal and shear forces acting within the plate at point (_{yx}x, y). However, they do not play a role in the (linear) plate theory since they do not cause an out-of-plane (transverse) displacement w.
These force and moment resultants should be in equilibrium with all external forces and moments. |