06.3.1 / CDS Training Manual
Predict T700/PR520
effective lamina properties.
A bottom-up micromechanics study using constituent values and three fiber-volume regions published for a NASA triaxial-braid model.
06.1 Manuals · read online, preview or download →
Current Workbench, reference editions and downloads
Use the online User Guide for current controls, the released model directory for selectable models and compatibility, and the Training Manual for connected exercises. Wider theory references do not mean every formulation is enabled in Workbench.
Screenshots and download editions carry revision dates; consult the current chapter for updated Workbench instructions. Find the overview PDF, guides and exercise databases in Your CDS library.
All blocks keep the CREATE / DISCOVER / SIMULATE positions, with Equipment below Geometry; unused records remain disconnected. This changes the view only, not the exercise records.
∑ Used models & submodels
Only models assigned to records used by this exercise are listed here. The full-layout option preserves the supplied starter records; no Workbench records are changed.
Halpin–Tsai · T700 / EP180 UD · Unidirectional lamina
One compatible homogenization model per Micro recipe. Separate recipes compare models; their predictions are not blended.
∑ Theory & assumptionsData travelling between blocks
Materials → Micro
Constituent stiffness, strength, density and thermal / moisture properties.
Models → Micro
Applied model assignment: Halpin–Tsai. Model parameters and formulation are used by Micro.
Reference validation · 2026-09-20
Not benchmark validated
No matched quantitative reference comparison completed for the full exercise.
Recorded baseline only—not a certification of the current database, edited inputs, or every output. Analytical agreement is not experimental material or failure validation.
Source validation, comparisons and tested inputs
Execution: Completed (not validation)
The copied T700/EP180 database is a connected starter, not T700/PR520. Complete the constituent setup below before comparing with NASA.
- NASA/TM—2015-218814 — Experimental and Numerical Analysis of Triaxially Braided Composites Utilizing a Modified Subcell Modeling Approach ↗Tables 3–4, printed page 7 / PDF page 11. MAC/GMC calculated effective ply data, not measured UD coupon properties.
Tested inputs
Input SHA-256: 98f09a9b013eb9fdb5252ce3245d15829776d94ac0390f4c85b46c581c424865
Solver source SHA-256: 21b57ba5585334998ad98a0b2bac916764c93739a20e81f92e8e37cd50006f4a
- Constituent-to-lamina screening only. The NASA braid subcells, calibrated LS-DYNA damage and coupon validation are not reproduced.
Separate published-data fixture: Benchmark discrepancy
Source-matched constituent fixture compared with NASA MAC/GMC, 1% exploratory equivalence criterion declared before running. A different homogenization model need not match; mismatch is retained, not fitted away.
| Quantity | CDS | Reference | Error % | Tolerance (relative + absolute) | Result |
|---|---|---|---|---|---|
| E1 at Vf=0.375 (GPa) | 88.75 | 88.5 | 0.2824859 | 1% + 0.00002 GPa | Pass |
| E2 at Vf=0.375 (GPa) | 5.51724 | 6.22 | -11.29839 | 1% + 0.00002 GPa | Discrepancy |
| G12 at Vf=0.375 (GPa) | 2.23256 | 2.6 | -14.13231 | 1% + 0.00002 GPa | Discrepancy |
| E1 at Vf=0.733 (GPa) | 169.658 | 169.5 | 0.09321534 | 1% + 0.00002 GPa | Pass |
| E2 at Vf=0.733 (GPa) | 8.64927 | 9.9 | -12.63364 | 1% + 0.00002 GPa | Discrepancy |
| G12 at Vf=0.733 (GPa) | 4.70445 | 7 | -32.79357 | 1% + 0.00002 GPa | Discrepancy |
| E1 at Vf=0.8 (GPa) | 184.8 | 184.7 | 0.05414185 | 1% + 0.00002 GPa | Pass |
| E2 at Vf=0.8 (GPa) | 9.67742 | 10.9 | -11.21633 | 1% + 0.00002 GPa | Discrepancy |
| G12 at Vf=0.8 (GPa) | 5.93407 | 6 | -1.098833 | 1% + 0.00002 GPa | Discrepancy |
- NASA/TM—2015-218814 — Experimental and Numerical Analysis of Triaxially Braided Composites Utilizing a Modified Subcell Modeling Approach ↗Tables 3–4, printed page 7 / PDF page 11. MAC/GMC calculated effective ply data, not measured UD coupon properties.
Fixture inputs
{
"fiber": {
"E1": 230,
"E2": 15,
"G12": 27,
"nu12": 0.2
},
"matrix": {
"E": 4,
"G": 1.44,
"nu": 0.38
},
"volumeFractions": [
0.375,
0.733,
0.8
],
"voidFraction": 0,
"model": "Rule of mixtures"
}Separate published-data fixture: Benchmark discrepancy
Source-matched constituent fixture compared with NASA MAC/GMC, 1% exploratory equivalence criterion declared before running. A different homogenization model need not match; mismatch is retained, not fitted away.
| Quantity | CDS | Reference | Error % | Tolerance (relative + absolute) | Result |
|---|---|---|---|---|---|
| E1 at Vf=0.375 (GPa) | 88.75 | 88.5 | 0.2824859 | 1% + 0.00002 GPa | Pass |
| E2 at Vf=0.375 (GPa) | 6.62252 | 6.22 | 6.471383 | 1% + 0.00002 GPa | Discrepancy |
| G12 at Vf=0.375 (GPa) | 2.90406 | 2.6 | 11.69462 | 1% + 0.00002 GPa | Discrepancy |
| E1 at Vf=0.733 (GPa) | 169.658 | 169.5 | 0.09321534 | 1% + 0.00002 GPa | Pass |
| E2 at Vf=0.733 (GPa) | 10.47761 | 9.9 | 5.834444 | 1% + 0.00002 GPa | Discrepancy |
| G12 at Vf=0.733 (GPa) | 7.00011 | 7 | 0.001571429 | 1% + 0.00002 GPa | Pass |
| E1 at Vf=0.8 (GPa) | 184.8 | 184.7 | 0.05414185 | 1% + 0.00002 GPa | Pass |
| E2 at Vf=0.8 (GPa) | 11.43662 | 10.9 | 4.923119 | 1% + 0.00002 GPa | Discrepancy |
| G12 at Vf=0.8 (GPa) | 8.80865 | 6 | 46.81083 | 1% + 0.00002 GPa | Discrepancy |
- NASA/TM—2015-218814 — Experimental and Numerical Analysis of Triaxially Braided Composites Utilizing a Modified Subcell Modeling Approach ↗Tables 3–4, printed page 7 / PDF page 11. MAC/GMC calculated effective ply data, not measured UD coupon properties.
Fixture inputs
{
"fiber": {
"E1": 230,
"E2": 15,
"G12": 27,
"nu12": 0.2
},
"matrix": {
"E": 4,
"G": 1.44,
"nu": 0.38
},
"volumeFractions": [
0.375,
0.733,
0.8
],
"voidFraction": 0,
"model": "Halpin–Tsai model"
}Download source-validation results (JSON) · Full 138-exercise study
Predict how T700/PR520 effective ply stiffness changes across the three local fiber-volume regions used in NASA’s absorbed-matrix braid model.
CDS reproduces a constituent-to-lamina comparison. It does not reproduce the report’s complete braid subcell, LS-DYNA damage calibration, or coupon validation.
Published basis
1 primary sourceStarting data
Enter in the displayed units| Variable | Value | How it is used |
|---|---|---|
| T700 density | 1.80 g/cm³ | Fiber physical property |
| T700 E1 / E2 | 230 / 15 GPa | Fiber axial and transverse modulus |
| T700 ν12 / G12 | 0.20 / 27 GPa | Fiber coupling and shear |
| PR520 density | 1.25 g/cm³ | Matrix physical property |
| PR520 E / ν / G | 4.0 GPa / 0.38 / 1.44 GPa | Isotropic matrix elasticity |
| Fiber volume fractions | 37.5%, 73.3%, 80.0% | Three separate micromechanics evaluations |
Review checkpoints
Comparison, not certification| Result | Published reference | Interpretation |
|---|---|---|
| Vf 37.5%: E1 / E2 / G12 | 88.5 / 6.22 / 2.60 GPa | B-braider effective ply |
| Vf 73.3%: E1 / E2 / G12 | 169.5 / 9.90 / 7.00 GPa | A/C-braider effective ply |
| Vf 80.0%: E1 / E2 / G12 | 184.7 / 10.9 / 6.00 GPa | A-axial effective ply |
138 exercises, examples and case studies → · Your CDS library: overview, manuals and database downloads →
Create traceable constituent records
Duplicate the nearest carbon-fiber and thermoset records so the library baselines remain unchanged.
Step-by-step instructions · 3 steps
- Name the records T700 — NASA case study and PR520 — NASA case study.
- Enter the density and elastic values from the starting-data table. For the isotropic matrix, use E = 4.0 GPa, ν = 0.38 and G = 1.44 GPa.
- Add the NASA report as the source, mark the values as published research inputs, and leave unsupported strength or transport terms visibly incomplete.
Link a continuous-fiber micromechanics model
Create or duplicate a unidirectional micromechanics record and link the T700 fiber and PR520 matrix.
Step-by-step instructions · 3 steps
- Choose a model that reports the full orthotropic lamina stiffness.
- Set void fraction to zero for the baseline comparison and keep empirical closure parameters at their documented defaults.
- Confirm Live Microstructure and the dependency summary point to the two case-study constituent records.
Sweep the three published fiber fractions
Use Lamina / Micro optimization or three duplicated model records to evaluate Vf = 37.5%, 73.3% and 80.0%.
Step-by-step instructions · 3 steps
- Hold all other inputs fixed and evaluate each volume fraction.
- Plot Vf against E1, E2 and G12; use a line view for the trend and the table for exact values.
- Save one optimization snapshot or export one comparison table containing all three cases.
Compare the effective lamina response
Compare CDS output with NASA’s MAC/GMC values in the checkpoint table. Expect the longitudinal trend to be strongest and model-dependent differences in transverse and shear response.
Step-by-step instructions · 3 steps
- Calculate percent difference as 100 × (CDS − reference) / reference for each modulus.
- Inspect the selected model’s assumptions before attributing differences to input data.
- Repeat with another supported homogenization model to show model-form sensitivity.
Save the predicted lamina for downstream work
Create a new lamina material from the selected prediction and retain the model and source links.
Step-by-step instructions · 3 steps
- Choose the fiber fraction appropriate to the intended region rather than averaging the three NASA subcells without justification.
- Save the generated material with Prediction status.
- Open the new record and verify that its provenance identifies both constituents and the micromechanics model.