Poisson's ratio (overmolding) results

Poisson's ratios are mechanical property values that indicate strain in a specific direction, caused by stress from another direction. These results are used in a subsequent Stress analysis.

Mesh type:
Analysis sequences that include:

To create these results, the Fiber orientation analysis if fiber material option must be selected, and a material with filler or fiber data must be chosen. This option can be found on the Fill+Pack Settings page of the Process Settings Wizard.

Tip: These results are not shown by default. To view these results, click (Result tab > Plots panel > New Plot) and select them from the list of Available results.
Important: If these results do not appear in the list of available results, check that you have a shrinkage model selected. Click (Home tab > Molding Process Setup panel > Process Settings) and click Advanced options. Click Edit associated with Molding material and select the Shrinkage Properties tab. Select a shrinkage model.

Poisson's ratio (averaged) (overmolding) result

The Poisson’s ratio (averaged) (overmolding) result indicates the average strain in the second principal direction for the overmolded component, caused by the stress in the first principal direction.

The Poisson’s ratio (averaged) (overmolding) result is a fiber-over-thickness (FOT) averaged value, which means that the Poisson's ratio is calculated for every element on every laminate and then for each of those elements, it is averaged over all the laminates.

Poisson's ratio (v12) (overmolding) result

The Poisson's ratio (v12) (overmolding) result indicates the strain in the second principal direction for the overmolded component, caused by stress in the first principal direction. This result is laminate-based, recorded for each element on each laminate in the model, over the duration of the analysis. Thus, each laminate in the model will have a different result.

In general, vi,j=Poisson's ratio for transverse strain in the j-direction when stressed in the i-direction.

Poisson's ratio (v13) (overmolding) result

The Poisson's ratio (v13) (overmolding) result indicates the strain in the third principal direction for the overmolded component, caused by stress in the first principal direction. This result is laminate-based, recorded for each element on each laminate in the model, over the duration of the analysis. Thus, each laminate in the model will have a different result.

In general, vi,j=Poisson's ratio for transverse strain in the j-direction when stressed in the i-direction.

Poisson's ratio (V23) (overmolding) result

The Poisson's ratio (v23) (overmolding) result indicates the strain in the third principal direction for the overmolded component, caused by stress in the second principal direction. This result is laminate-based, recorded for each element on each laminate in the model, over the duration of the analysis. Thus, each laminate in the model will have a different result.

In general, vi,j=Poisson's ratio for transverse strain in the j-direction when stressed in the i-direction.

Orthotropic assumption

The thermo-mechanical property calculation for fiber-filled composites is 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, and only these four are used in the (averaged) results.

The Orthotropic set option is set by default and, unless the results are averaged, selects the 9 mechanical constants (E1, E2, E3, v12, v23, v13, G12, G23, G13) and 3 CTE’s (thermal expansion coefficient in first/second/third directions) all at once.
Note: To access the Orthotropic set option ensure you have selected an analysis sequence that includes Fill+Pack.
  1. Click Process SettingsHome tab > Molding Process Setup panel > Process Settings.
  2. If necessary, click Next until you reach the Fill+Pack Settings page of the Wizard.
  3. Select the option Fiber orientation analysis if fiber material, and then click Fiber parameters.
  4. Click Composite property calculation options, and then from the Fiber-filled property output drop-down list, select Orthotropic set.

Using this result

Look at the Poisson's ratio (averaged) (overmolding) result to view the strain at a given point and compare it with the strain at other points on the model. The other results can be used for an more detailed study of the strain through the thickness.

For all but the Poisson’s ratio, (averaged) (overmolding) result, the results are laminate-based, so you can view the Poisson’s ratio distribution for each laminate in the model.

You can view the contour plot of a single laminate on the model, by clicking (Results tab > Properties panel > Plot Properties). Select the Animation tab, and from the Animate result over drop-down list, select Single dataset.

Tip: Click (Result tab > Plots panel > New Plot) and create this result as an XY or Path plot also, so you can view the Poisson's ratio distribution at a particular element, or with respect to the model geometry.
Parent topic: Overmolding results