Straightening out the Adoption of Variable Stiffness Composite Laminates in Aerospace Industry

Significant improvements in the mechanical performance of a laminated composite structure can be achieved by spatial variation of the stiffness properties within the laminate. Such a variable stiffness (VS) laminate, typically is created by steering the fibers within the laminae, resulting in an in-plane variation of stacking sequence and thus...

A finite element investigation of the mechanical effect of ply drops in blended laminates

Weight reduction in vehicles offers many advantages. Especially in aircraft, one of the advantages of weight reduction less need for power which is translated into less fuel consumption and lower emissions. Composite materials are now a popular construction material in new passenger aircraft, making them lighter by taking advantage of their high...

Stacking Sequence Retrieval of Large Composite Structures in Bi-step Optimization Strategies Using Mechanical Constraints

Multi-step optimization of large composite structures involves formulating the stiffness distribution in terms of lamination parameters that provide a continuous design space, followed by a second optimization in the discrete design space to obtain equivalent stacking sequences. The retrieval of stacking sequences is often challenging as a...

Laminate Blending Demonstrator: A buckling experimental campaign of a physical laminate blending demonstrator

The use of fiber-reinforced composites in the aerospace industry has increased over the past couple of decades thanks to their high specific properties. Fiber-reinforced composites also enable engineers to tailor the stacking sequence to satisfy the required stiffness or strength requirements. However, locally optimizing the stacking sequence of...

Overcoming the curse of dimensionality in composite laminate blending: A CA-based algorithm for blending laminated composite plates with a large amount of sections

The specific properties of fibre reinforced laminated composite plates can be optimized by tailoring the local stacking sequences to approach the locally required stiffness and strength. Blending enforces continuation of some or all plies from one stacking sequence to another to ensure structural integrity and manufacturability. Effectivity in...

Optimum lay-up design of variable stiffness composite structures

Advancements in automated fibre-placement (AFP) technology make it possible to take laminate tailoring further than just stacking sequence optimisation; they enable the designer to vary the fibre orientation angle spatially within each ply. Spatial variation of fibre orientation angles results in a variable stiffness (VS) laminate. The work...