Tensile modulus (3D fiber) (overmolding) results

The Tensile modulus (3D fiber) (overmolding) results indicate how much stress is needed to cause a unit of movement in the overmolded part.

Mesh type:

• 

Analysis sequences that include:

• Overmolding Pack

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 you don't see these result, 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.

The tensile modulus is calculated for every tetrahedral element, through the thickness of the part, at the end of the analysis, using the fiber orientation tensor at that tetrahedral element. These results are used by the CRIMS shrinkage correction model and the uncorrected residual stress model. You can view the expansion coefficient at each node by animating the default contour plot, which will animate the result through the part.

• Tensile modulus in first principal direction (3D fiber) (overmolding)
• Tensile modulus in second principal direction (3D fiber) (overmolding)
• Tensile modulus in third principal direction (3D fiber) (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.

The Orthotropic set option is set by default and 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. In a Fiber analysis, the complete set of thermo-mechanical properties with orthotropic assumption is necessary for a Warp analysis. These properties are element-based, so each tetrahedral or beam element has its own orthotropic set of properties.

Note: To access the Orthotropic set option ensure you have selected an analysis sequence that includes Fill+Pack.

1. Click Home 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

The first principal direction coincides with the fiber orientation first principal direction, and is determined by the Fiber orientation Fill+Pack analysis. The second principal direction is perpendicular to the first principal direction. You should expect more pressure to be required in the first principal direction, and less pressure in the third principal direction, as the fiber orientation increases. If the molecules are randomly aligned, then the results will be similar in all directions.

View these results in conjunction with one another to determine the average tensile moduli pressures (MPa) in all three principal directions.