Today's KNOWLEDGE Share : 𝗔 𝗦𝗺𝗮𝗹𝗹 𝗧𝗵𝗶𝗰𝗸𝗻𝗲𝘀𝘀 𝗗𝗲𝘃𝗶𝗮𝘁𝗶𝗼𝗻 𝗧𝗵𝗮𝘁 𝗘𝘃𝗲𝗿𝘆 𝗖𝗼𝗺𝗽𝗼𝘀𝗶𝘁𝗲 𝗘𝗻𝗴𝗶𝗻𝗲𝗲𝗿 𝗘𝗻𝗰𝗼𝘂𝗻𝘁𝗲𝗿𝘀

Today's KNOWLEDGE Share

💡 𝗔 𝗦𝗺𝗮𝗹𝗹 𝗧𝗵𝗶𝗰𝗸𝗻𝗲𝘀𝘀 𝗗𝗲𝘃𝗶𝗮𝘁𝗶𝗼𝗻 𝗧𝗵𝗮𝘁 𝗘𝘃𝗲𝗿𝘆 𝗖𝗼𝗺𝗽𝗼𝘀𝗶𝘁𝗲 𝗘𝗻𝗴𝗶𝗻𝗲𝗲𝗿 𝗘𝗻𝗰𝗼𝘂𝗻𝘁𝗲𝗿𝘀 (𝗦𝗼𝗼𝗻𝗲𝗿 𝗼𝗿 𝗟𝗮𝘁𝗲𝗿)

In composite design, one of the most common sources of deviation between FE predictions and real component behaviour is not modelling error, not boundary conditions, and not manufacturing defects. It is simply this:

👉 𝗧𝗵𝗲 𝗰𝘂𝗿𝗲𝗱 𝗽𝗹𝘆 𝘁𝗵𝗶𝗰𝗸𝗻𝗲𝘀𝘀 𝘂𝘀𝗲𝗱 𝗶𝗻 𝘁𝗵𝗲 𝗮𝗻𝗮𝗹𝘆𝘀𝗶𝘀 𝗱𝗼𝗲𝘀 𝗻𝗼𝘁 𝗺𝗮𝘁𝗰𝗵 𝘁𝗵𝗲 𝗮𝗰𝘁𝘂𝗮𝗹 𝗰𝘂𝗿𝗲𝗱 𝘁𝗵𝗶𝗰𝗸𝗻𝗲𝘀𝘀 𝗼𝗳 𝘁𝗵𝗲 𝗹𝗮𝗺𝗶𝗻𝗮𝘁𝗲 (𝘩𝘰𝘸 𝘮𝘢𝘯𝘺 𝘵𝘪𝘮𝘦𝘴 𝘸𝘦 𝘧𝘢𝘤𝘦 𝘪𝘵..!)

This issue appears across aerospace, defence, UAV and industrial composites….especially when changing prepreg supplier, fibre type, or impregnation method. And it is fully measurable: the laminate behaves differently because 𝗶𝘁𝘀 𝗯𝗲𝗻𝗱𝗶𝗻𝗴 𝘀𝘁𝗶𝗳𝗳𝗻𝗲𝘀𝘀 𝗶𝘀 𝗱𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝘁.

𝘛𝘩𝘪𝘴 𝘪𝘴 𝘢 𝘷𝘦𝘳𝘺 𝘵𝘺𝘱𝘪𝘤𝘢𝘭 𝘦𝘯𝘨𝘪𝘯𝘦𝘦𝘳𝘪𝘯𝘨 𝘴𝘤𝘦𝘯𝘢𝘳𝘪𝘰:

A laminate nominally defined as 4 × 0.20 mm = 0.80 mm ends up curing at 0.88 mm.

The part is within process tolerances, visually perfect, and mechanically sound. However, from a structural standpoint, the difference is significant.

For thin laminates, bending stiffness scales approximately with the third power of thickness:

D ∝ t³

If the laminate increases from 0.80 mm → 0.88 mm:

• Thickness ratio: 0.88/0.80=1.10

• Bending stiffness ratio: 〖1.10〗^3≈1.33

➡️ ≈ +𝟯𝟯% 𝗯𝗲𝗻𝗱𝗶𝗻𝗴 𝘀𝘁𝗶𝗳𝗳𝗻𝗲𝘀𝘀

This is not a secondary variation.....it's a structural shift. It can modify:

• deformation under operational loads,

• load distribution across bonded interfaces,

• flutter / frequency response,

• and geometric fit at assemblies relying on nominal laminate thickness.

💰 𝗣𝗿𝗮𝗰𝘁𝗶𝗰𝗮𝗹 𝘁𝗮𝗸𝗲𝗮𝘄𝗮𝘆 𝗳𝗼𝗿 𝗰𝗼𝗺𝗽𝗼𝘀𝗶𝘁𝗲 𝗲𝗻𝗴𝗶𝗻𝗲𝗲𝗿𝘀

To ensure correlation between FEM and physical behaviour:

• Use validated ply cured thickness values, not catalogue nominal values.

• Perform early PCT measurements during material qualification.

• Update laminate definitions in the FEM accordingly.

• Revalidate PCT when switching supplier, fibre architecture or cure process.

• Treat PCT as a primary design parameter, not a secondary output.

𝗧𝗵𝗶𝘀 𝘀𝗶𝗻𝗴𝗹𝗲 𝗱𝗶𝘀𝗰𝗶𝗽𝗹𝗶𝗻𝗲 𝗰𝗹𝗼𝘀𝗲𝘀 𝗮 𝗹𝗮𝗿𝗴𝗲 𝗽𝗼𝗿𝘁𝗶𝗼𝗻 𝗼𝗳 𝘁𝗵𝗲 “𝗙𝗘𝗠 𝘃𝘀 𝗿𝗲𝗮𝗹𝗶𝘁𝘆” 𝗴𝗮𝗽 𝗼𝗯𝘀𝗲𝗿𝘃𝗲𝗱 𝗶𝗻 𝗰𝗼𝗺𝗽𝗼𝘀𝗶𝘁𝗲 𝗰𝗼𝗺𝗽𝗼𝗻𝗲𝗻𝘁𝘀.

𝗙𝗿𝗼𝗺 𝗯𝗼𝗼𝗸:

👉 Composite Materials for Technical Education

https://lnkd.in/eWR_dV4k

source : M.Eng. M.Sc. GABRIELE C.

#composites #carbonfiber #compositeengineering #FEM

#FEA #materialsengineering