Name a strategy to reduce delamination risk.

Name a strategy to reduce delamination risk.

• A. Use a well-designed stacking sequence with gradual thickness transitions and/or interleaves, choose toughened resin, and ensure proper bonding and cure
• B. Use very thick plies with abrupt thickness changes and brittle resin
• C. Avoid pre-curing steps
• D. Increase cure temperature to extremes

Answer: (A)

Reducing delamination risk comes from improving interlaminar toughness and minimizing peel stresses at ply interfaces. A strategy that combines a well-designed stacking sequence with gradual thickness transitions and/or interleaves, plus using a toughened resin and ensuring proper bonding and cure, directly addresses those factors. Gradual thickness changes lessen sharp stress concentrations that occur during bending or impact, while a thoughtful stacking sequence helps distribute loads to avoid high interlaminar stresses. Interleaves can interrupt crack growth and absorb energy, and a tougher resin raises the energy needed for a delamination to propagate. Ensuring good bonding and a proper cure avoids weak interfaces from voids, poor wetting, or residual stresses. Using very thick plies with abrupt thickness changes and brittle resin increases the likelihood of stress concentrations and offers little resistance to crack growth. Skipping appropriate pre-curing steps or pushing cure temperatures to extremes can introduce residual stresses or degrade interlaminar toughness, both of which make delamination more likely.

Reducing delamination risk comes from improving interlaminar toughness and minimizing peel stresses at ply interfaces. A strategy that combines a well-designed stacking sequence with gradual thickness transitions and/or interleaves, plus using a toughened resin and ensuring proper bonding and cure, directly addresses those factors. Gradual thickness changes lessen sharp stress concentrations that occur during bending or impact, while a thoughtful stacking sequence helps distribute loads to avoid high interlaminar stresses. Interleaves can interrupt crack growth and absorb energy, and a tougher resin raises the energy needed for a delamination to propagate. Ensuring good bonding and a proper cure avoids weak interfaces from voids, poor wetting, or residual stresses.

Using very thick plies with abrupt thickness changes and brittle resin increases the likelihood of stress concentrations and offers little resistance to crack growth. Skipping appropriate pre-curing steps or pushing cure temperatures to extremes can introduce residual stresses or degrade interlaminar toughness, both of which make delamination more likely.