Product help with community knowledge

# Tensile modulus, principal direction (fiber) results

The Tensile modulus, principle direction (fibre) result indicates how much stress is needed to cause a unit of movement.

This help topic describes the following fiber orientation Pack analysis results, and indicates how much stress is needed to cause a unit of movement:

• Tensile modulus in first principal direction (fiber)
• Tensile modulus in second principal direction (fiber)
• Tensile modulus in third principal direction (fiber)-3D analysis technology only

## Using these results

For a Fiber and Dual Domain Fiber analysis, the Tensile modulus in first and second principal (fiber) results generate fiber-over-thickness (FOT) averaged values, which means that they are element-based values averaged over all the laminates of each element. For a 3D Fiber analysis, Tensile modulus, principal direction (fiber) results are recorded for each element in the model at the end of the analysis.

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. If the first and second principal directions are X, and Y respectively, then Z is the third principal direction.

View these results in conjunction with one another to determine the average tensile moduli pressures (Mpa) in the first, second, and third principal directions.

Note For more detailed information on the tensile modulus, view the Tensile modulus in first and second principal direction results, which are recorded for each laminate in the model using Midplane or Dual Domain technology.

## Orthotropic assumption

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 Midplane/Dual Domain models, 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.

The Orthotropic set option 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 using 3D analysis technology, the complete set of thermo-mechanical properties with orthotropic assumption is necessary for a Warp analysis using 3D analysis technology. These properties are element-based, so each tetrahedral or beam element has its own orthotropic set of properties.

NoteTo 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. The Process Settings Wizard dialog opens.
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. The Fiber Orientation Solver Parameters dialog opens
4. Click Composite property calculation options, and then from the Fiber-filled property output drop-down list, select Orthotropic set.