Inspection & Testing · Component review guide · Litian Yunde
Identify what the test represents. Original explanatory schematic; not to scale and not a product test result.
A composite test coupon provides evidence for the specimen and test conditions recorded. It does not automatically qualify every finished part made from similarly named carbon fiber. Connect the test report to material, layup, process, geometry and the requirement being assessed.
Identify the specimen before reading the number
Check the material system, specimen orientation, preparation and conditioning reported. Confirm the test method and the measured property. A result for fibre, laminate or a bonded coupon describes a different object from a complete component. If the report does not identify the specimen sufficiently, request clarification before using it as an acceptance basis.
Compare the variables that matter
A production part may include holes, curves, joints, inserts, thickness transitions and a different loading arrangement. List the differences between the specimen and the part, then ask the responsible engineer what additional evidence is needed. Do not apply a coupon value directly as a permitted load on a finished component without the necessary analysis and validation.
Use witness samples for a defined purpose
A witness coupon can accompany a production process, but its role should be agreed beforehand. Identify whether it supports material verification, process monitoring or a particular bond review. Keep its batch relationship and processing record. A witness label alone does not establish that the coupon experienced every relevant condition of a complex finished part.

Example: a machined bracket offered with a laminate report
The supplier provides a laminate test report with a bracket quotation. The buyer checks the report’s material and orientation, then asks how the bracket’s holes, geometry and service loading are addressed. The laminate result stays in the evidence package as background; the bracket’s acceptance requirements remain tied to its own drawing and validation plan.
Scénario à titre d'exemple ; il ne s'agit ni d'un cas client ni d'un résultat de production avéré.
Éléments à convenir avant de passer commande
| Article à évaluer | Consigner pour accord |
|---|---|
| Specimen identity | Material, layup/orientation and specimen geometry. |
| Test conditions | Method, conditioning and reported property. |
| Part comparison | Geometry, process, joints and loading differences. |
| Evidence role | What the report supports and what remains unverified. |
Questions posées par les acheteurs
Can a material certificate replace a finished-part test?
Only where the agreed acceptance plan permits that evidence for the stated requirement.
Is a supplier’s high strength number enough?
No. Its specimen, direction, test conditions and relevance to the part must be clear.
Contexte technique et lectures complémentaires
Document d'information : Hexcel : Technologie des préimprégnés. La liste de contrôle du projet et l'exemple ci-dessus constituent des recommandations rédactionnelles ; ce document ne certifie pas un composant Litian Yunde.
- Comment lire la fiche technique d'un matériau en fibre de carbone sans en exagérer les propriétés
- Vérification des gabarits pour les pièces en fibre de carbone : que signifie un résultat « conforme/non conforme » ?
- Parcourez le centre de connaissances sur la fibre de carbone
Passez en revue votre composant avec Litian Yunde
Veuillez nous communiquer la version révisée du plan, l'application prévue ainsi que la question relative à l'interface ou au contrôle que vous souhaitez voir résolue. Les exigences de construction et de réception mentionnées sont validées pour ce projet spécifique.
