New AMADE publication investigates the Effect of Ply Misalignment on the Notched Strength of Composite Laminates
A recent study co-authored by the Spanish CAELESTIS partner AMADE, the Analysis and Advanced Materials for Structural Design, research group at the University of Girona, quantifies how small misalignments in fibre orientation reduce strength around notches in composite laminates. The paper also introduces a hybrid modelling approach that predicts these effects more efficiently, balancing accuracy and computational cost.
Understanding a Key Challenge in Composite Design
Predicting the notched strength of carbon fiber-reinforced polymers (CFRPs) is essential in composite structure design. This process must account for uncertainties such as geometric features (e.g. holes or notches), material variability and manufacturing defects.
Traditionally, such assessments relied on extensive experimental campaigns. Today, however, advances in computational (high-fidelity) and analytical (low fidelity) modelling enable engineers to predict material behaviour with far greater efficiency.
AMADE’s Innovative Methodology
In their new publication in the Composite structures journal, AMADE researchers examined the influence of ply misalignment at the meso-scale level, a common but often overlooked manufacturing deviation.
To establish more reliable notched strength allowables, they combined analytical and computational tools within a hybrid modelling framework:
- Analytical (low-fidelity) models: Fast to run but limited in representing stacking sequence effects and ply deviations.
- Finite Element (high-fidelity) models: Computationally intensive but capable of captuing local effects with precision.
By in integrating both approaches, AMADE created a workflow that delivers accurate, detailed strength predictions while keeping computational requirements manageable for design exploration.
Key Findings
The study found that both analytical and the numerical models are well aligned with their experimental results, confirming the reliability of the hybrid approach. Notably, the analyses demonstrated that ply misalignment significantly reduces notched strength compared to perfectly aligned laminates.
Moreover, the new method enables the derivation of strength allowables that already account for realistic manufacturing deviations, supporting designs that are safer yet less conservative.
Advancing Next-Generation Aircraft Design
These new findings by AMADE CAELESTIS scientists offer valuable contributions to the digital design and manufacturing of next-generation aircraft in Europe. Their research bridges design and manufacturing by incorporating realistic manufacturing variability into predictive models, while also accelerating design exploration by reducing the need for thousands of high-cost finite-element simulations. Moreover, it enables reliability-aware design, helping engineers minimise weight penalties caused by overly conservative safety margins. Through this work, AMADE continues to advance digital twin-based approaches that bring aircraft design closer to real-world manufacturing realities, a key objective of the CAELESTIS project.
