Model β-turn inducers were prepared from constrained oxazanorbornene aminols. Taking advantage of the starting materials geometry, new diastereoisomeric compounds were synthesized, introducing different amino acidic residues. The products were spectroscopically characterized (VT and NMR titration). Temperature coefficients in dimethyl sulfoxide denote the existence of an intramolecular hydrogen bond. Chiroptical properties disclosed a β-turn arrangement of the synthesized compounds. The fused isoxazoline ring constraints the cyclopentane moiety, stabilizing a boatlike conformation that ensures the turn efficiency but limiting the accessibility to hindered amino acids.

This paper describes an innovative methodology which automatically creates a 2D-axisymmetric finite element (FE) model of a quasi-axisymmetric component from its 3D CAD model. The process has been implemented as a script and uses the API to a commercial FE package. The calculation of a volume shape coefficients to be applied in the non-axisymmetric regions of the FE model, to account for the fact the region is not fully axisymmetric, is also described. In the paper, the methodology is demonstrated for a rotating blade of tapered profile analyzing and comparing both stresses and displacement. Excellent results are shown.

Design and manufacturing of composite structures are driving the next generation innovation cycles for the aerospace, automotive and energy markets. Automated fiber placement (AFP) is quickly becoming the preferred manufacturing method of those structures as it offers manufacturing automation, reduces production cycle times, and decreases human induced errors. One of the major steps towards manufacturing structures with AFP technology is the selection of the optimal layup strategy. This is limited by, not only geometrical and process parameters, but certification allowable and guidelines. This paper outlines a systematic review of the multiple layup strategies practices currently used and/or investigated for the AFP manufacturing process. The optimal layup strategy needs to be selected and verified to obtain laminates with little to no manufacturing defects. Through a methodical description, the different layup strategies found in the literature are described as well as their mathematical implementation. Following, a geometrical benchmark is presented so that new layup strategies can be compared to others based on the same reference. The article can be the foundation for any new layup strategy investigation.

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