Tensile modulus (overmolding) results

The Tensile modulus (overmolding) results indicate how much stress is needed to cause a unit of movement in the overmolded component.

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.

For a Midplane or Dual Domain overmolding analysis of a fiber filled material, the tensile modulus is calculated in the three principal directions of the fiber orientation tensor. Two types of results are then published:

Tensile modulus (averaged) (overmolding) results

For each element, the tensile modulus is calculated using an orientation average across the thickness, using the fiber orientation tensor of that element. Although data is calculated in all three principal directions, it is only written into the results file for the first and second principal directions. These results are used by the legacy residual strain shrinkage model, which does not use the data from the third principal direction.
  • Tensile modulus in first principal direction (averaged) (overmolding) result
  • Tensile modulus in second principal direction (averaged) (overmolding) result

Tensile modulus results

For each element of the overmolded component, the tensile modulus is calculated at each laminate for the duration of the analysis, using the fiber orientation tensor of that element. Therefore, each laminate in the overmolded component will have a different tensile modulus result. These results are used by the CRIMS shrinkage correction model and the uncorrected residual stress model. You can check the results in each laminate by animating the default contour plot, which will animate the result over the Normalized Thickness.
  • Tensile modulus in first principal direction result (overmolding)
  • Tensile modulus in second principal direction result (overmolding)
  • Tensile modulus in third principal direction result (overmolding)

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 these results

Compare the results in each of the different principal directions. You should expect more force to be required in the direction of flow (first principal direction) than perpendicular to the flow direction (second principal direction). If the molecules are aligned in the first and second principal directions, then the tensile modulus will be different in each principal direction. If the molecules are randomly aligned, you would expect to see a uniform tensile modulus result in each principal direction.

The first principal direction coincides with the fiber orientation first principal direction, and is determined by the Fiber orientation analysis. The second principal direction is perpendicular to the first principal direction.

Tip: You can view the contour plot at a single laminate on the model. To do so, click Plot PropertiesResults tab > Properties panel > Plot Properties. The Plot properties dialog opens. Select the Animation tab, and from the Animate result over drop-down list, select Single dataset.
Tip: Click New PlotResults tab > Plots panel > New Plot and under Plot type, click XY plot or Path plot, so that you can view the tensile modulus in the first or second principal direction at a particular element.

Tensile modulus is a mechanical property value. The distribution of this mechanical property is used by the structural analysis for its performance evaluation in a Stress analysis.

Parent topic: Overmolding results