Coupling Behavior in Composites

Composite laminates exhibit coupling behavior which is required to interpret the deformation and stress results. The coupling behavior for example makes the composite laminates an attractive choice for use in aircraft as forward swept wings.

• An unsymmetric laminate shows different couplings in response to external loading. For example, a tensile load can cause bending or twisting. The following couplings are possible for tensile and bending loads:

• • Extension-Bending, Extension-Twisting, Extension-Shearing-Bending-Twisting.

• • Bending-Extension, Bending-Shearing, Bending-Twisting-Extension-Shearing.

• A symmetric laminate generally shows the following couplings for tensile and bending loads:

• • Extension-Shearing.

  • Bending-Twisting.

Examples of Extension-Bending coupling and Extension-Twisting coupling are shown below. Extension in one direction causes bending or twisting.

You can customize the behavior of laminates to suit specific applications by carefully selecting the ply layup.

Related Topic

Composite Shells