The Poisson’s ratio (fiber) result is a fiber-over-thickness (FOT) averaged value, therefore, it is an element-based value averaged over all the laminates of each element.
This result is generated from a Fiber orientation Pack analysis.
The Poisson’s Ratio (fiber) result indicates the average strain in the second principal direction caused by the stress in the first principal direction.
The Poisson’s ratio, (v12) result is a laminate-based value, therefore, you can view the Poisson’s ratio distribution for each laminate in the model. You can check this result for more detailed information on the Poisson’s ratio distribution.
Poisson’s ratios are mechanical property values. The distribution of this mechanical property is used by the structural analysis for its performance evaluation in a Stress 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 using 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.