06.2 / CDS Training Manual

Exercises

Choose a question to work through. Open its connected study, change the prescribed inputs and use the checkpoints to explain the result.

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Exercise curriculum

Shared CDS database

CREATEDesign a starting point DISCOVERExplore the live laminate SIMULATELaunch Workbench

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Exercises

Choose an exercise to see its setup. Double-click or press Enter to open it in Workbench.

Exercise · 30 min

02.11 · Thin-wall pressure vessel

Level 3
IntermediateEst. 30 min

02 · Design & applications · 06-pressure

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About this workflow view

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. The diagram shows the setup, not solved results.

∑ 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 · IM7 / 8552 UD · Pressure vessel

One compatible homogenization model per Micro recipe. Separate recipes compare models; their predictions are not blended.

∑ Theory & assumptions

CLT · Linear thin-wall membrane · Cylinder — Internal Pressure · Pressure vessel

Shared laminate stiffness drives this membrane/CLT path. Failure criteria are independent comparisons, not blended models. Fatigue is a separate assessment.

∑ Theory & assumptions

Data travelling between blocks

Micro → Laminates
Predicted ply stiffness, strength, density and expansion properties.

Materials → Micro
Constituent stiffness, strength, density and thermal / moisture properties.

Mechanical → Simulation
SIMULATION selects this case and its analysis model; the case owns its applicable cycle and input references.

Laminates → Mechanical
Ply angles and thicknesses, stiffness, mass and ply properties.

Geometry → Mechanical
Part shape and dimensions, thickness or section definition, and model-specific geometric inputs. Each selected case consumes only the dimensions its model supports.

Models → Micro
Applied model assignment: Halpin–Tsai. Model parameters and formulation are used by Micro.

Models → Mechanical
Applied model assignment: CLT · Linear thin-wall membrane. Model parameters and formulation are used by Mechanical.

What this exercise will help you understand

Pressure loading produces different hoop and axial demands, and the end condition helps determine that balance. This exercise connects the vessel geometry and loading to the laminate response, then uses layup comparisons to explore how the same membrane demands are carried by different stacks.

Application: Pressure vessel
Baseline models: Halpin–Tsai · CLT · Linear thin-wall membrane
Geometry: Circular tube

Reference validation · 2026-10-31

Benchmark validated — analytical scope

Thin-wall pressure equilibrium and orthotropic biaxial strain comparison; stiffness inputs are conditional where Micro closure has not been verified.

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)

Nonzero-void closure has no matched published calibration in this study

Acceptance: absolute error ≤ absolute tolerance + relative tolerance × |reference|.
Quantity	CDS	Reference	Error %	Tolerance (relative + absolute)	Result
Hoop stress (MPa)	56.4	56.4	0	0.01% + 0.00002 MPa	Pass
Axial stress (MPa)	28.2	28.2	0	0.01% + 0.00002 MPa	Pass
Hoop strain including Poisson coupling (µε)	755.3712	755.3698	0.0001824025	0.05% + 0.01 µε	Pass
Axial strain including Poisson coupling (µε)	246.3161	246.3132	0.001149021	0.05% + 0.01 µε	Pass

MIT / David Roylance — Pressure Vessels ↗Equations 2–3, printed page 3; orthotropic strain compliance from laminated plates reference. Thin-wall, closed-end pristine cylinder. No slit, fracture or failure-pressure validation.
MIT / David Roylance — Laminated Composite Plates ↗Transformed plane-stress constitutive law and laminate extensional stiffness, equations 10–11 and 20–25. Independent strain/stress transformation and thickness integration; prescribed input elasticity is not validated.

Tested inputs

Pressure reference inputs

{"pressureMPa":2.4,"externalPressureMPa":0,"innerRadiusMm":47,"wallMm":2,"closed":true,"axialNPerM":0}

Input SHA-256: 1de482a6e7dd14f5b66f5582d58c30b5f08af6a2b097f380ed49640e2fc60fc7
Solver source SHA-256: cde316d69ee40b2714f26fd4d6d822f774242b37323c9419f2b6142aff317ca9

Thin-wall membrane theory: no through-wall radial stress profile or local end effects.

Download source-validation results (JSON) · Full 184-exercise study

Preparing a meaningful comparison

Check the radius or diameter convention and whether the ends are closed before running. Keep pressure and geometry unchanged during the ply-balance comparison. Where the exercise supplies membrane relations or published data, use them as a transparent check and document exactly which quantities are being compared.

Before editing, open the exercise in Workbench and check which simulation is selected. Follow the map above to see how its inputs connect; the map shows the setup, not a solved result. Read the input summary and validation notices. Make an independent copy when you need a separate variation, so shared reference records stay available.

Working through the exercise

Step 1
Inspect the tube dimensions in Geometry and pressure/end conditions in CASES.
Step 2
Run the closed-end vessel; compare hoop and axial membrane resultants.
Step 3
Vary the hoop/axial ply balance and rerun without changing the geometry or pressure.

Understanding your results

Keep global membrane behaviour separate from local damage tolerance. If the source discusses slits, cracks or delamination that the selected model does not resolve, document those exclusions rather than inferring their failure pressure from a pristine laminate calculation. Report both the useful global result and the additional analysis needed for the local question.

Use the checkpoints to see whether your explanation fits the intended comparison. Put the relevant result beside each one. If a result differs, work back through the inputs, model assumptions and numerical settings to explain why.

For zero external pressure, closed ends and no additional axial load, hoop resultant is twice the pressure-induced axial resultant.
Verify the wall is sufficiently thin for the selected theory.

Writing your conclusion

Explain what you changed, what happened and why. Compare the baseline with your new result, and say where the behaviour agrees with the selected formulation or needs another check. Include a labelled plot or table with units and its input state so someone else can follow the work.

Save the study with the solver notices and your checks. State the limits that affect this result, including illustrative data or missing calibration. Completing the exercise shows the comparison you made; claim benchmark validation only where the source-validation panel explicitly supports it.

Theory for this exercise

CLT and the ABD constitutive equations
Follow transformed ply stiffness, thickness and angle into membrane, bending and coupled response.
Pressure and membrane resultants in a laminated cylinder
Relates pressure, axial force and torque to laminate stress resultants and the thin-wall idealization.

Model limits

Thin-wall membrane theory: no through-wall radial stress profile or local end effects.

Operating guidance and source references

How the shared curriculum works

Read the reference
Select an exercise from the shared CDS database
Trace inputs in Simulation
Run and inspect fields
Compare checkpoints and record limits

SIMULATION selects the Thermal, Moisture, Mechanical and EM cases to run, with None available in each slot. Geometry owns shared specimen dimensions; Laminate owns plies and thickness. Equipment, directly below Geometry, owns reusable laser, IR/UV lamp, heater, cooler and mold specifications. Cases link that hardware to its placement and exposure; a boundary temperature alone does not imply a hardware model. Each case owns one analysis model, its applied conditions and its applicable cycle; there is no separate Process block. Surrounding blocks manage available records. Run updates results; completed does not mean validated or passed.

You work from one shared default database across all 184 exercises, examples and case studies. Opening an exercise selects its connected records without adding duplicate materials. An edit to a shared record affects every study that uses it, so duplicate the record for an independent variation. Downloads contain self-contained subsets and require sign-in with an active CDS license. Exercise links open the guide; they do not run the solver or replace your database. Historical files remain in the separate portal archive.

Catalogue revision 2026-09-20. Source-data case studies require the setup and calibration described in their guides.

For ATP frame comparisons, use the compact ATP curriculum and retained sensitivity references.

Keep the results and checks with your saved study so you can explain how you reached the conclusion. Use the User Guide for the controls and the Theory Manual for the mathematics.

Choose the run in the SIMULATION block

SIMULATION is the control point for the run. Select a Thermal case, Moisture case, Mechanical case and EM case, or None in any slot. Each selected case shows its analysis model, laminate and applicable geometry.

Step-by-step instructions · 4 steps

Keep candidate records in the surrounding blocks. Adding a candidate does not select it for execution.
Select the required cases in SIMULATION and review their inputs before Run. At least one case is required.
Use the same laminate for a supported combined run. Run standalone studies separately with the other selectors set to None.
Run executes the selected combination. A connection or Used marker is not confirmation of a successful solve.

Review every downstream geometry dependency

A geometry record can be shared by several cases and simulations. Editing its dimensions or type affects all linked consumers, including studies that are not currently open. Unrelated records are unchanged.

Step-by-step instructions · 4 steps

After editing geometry, open Solver messages and expand Review affected cases and simulations. Select a linked name to inspect that record.
Check the selected model, load basis, dimensions and boundary conditions. Loads are not automatically replaced when the geometry changes.
Resolve incompatible geometry and model combinations before running. An I-section does not turn a plate theory into a beam theory.
Rerun affected simulations before relying on previous results. Inputs changed warnings indicate that stored results no longer match their connected inputs.

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