The Shear modulus (G12) result shows the shear strain applied in the XY direction, coinciding with the fiber orientation direction.
The Shear modulus, sometimes called the rigidity modulus, refers to the change produced by a tangential stress, and provides a measure of how "stiff" the material is.
This result is generated from a Fiber orientation Pack analysis.
For a Midplane and Dual Domain analysis, the Shear modulus (G12) result is recorded for each laminate in the model over the duration of the analysis. Therefore, each laminate in the model will have different results. You can check the shear modulus in each laminate by animating the default contour plot, which will animate the result over the Normalized thickness.
For a 3D Fiber orientation analysis, the Shear modulus (G12) result is recorded for each tetrahedral element at the end of the analysis.
The thermo-mechanical property calculation for fiber-filled composites are based on the orthotropic assumption, that fiber-filled material properties are different in three orthogonal principal directions. Under this assumption, there are 9 independent mechanical constants and three independent thermal expansion coefficients. In models analysed with Midplane or Dual Domain analysis technologies, because of the plain stress assumption in the shell structure analysis in Warp, only 4 mechanical constants (Tensile modulus in first/second principal directions, Poisson ratio v12, Shear modulus G12) are necessary.