Nanotures (Spain)

Partner(s) : COMPOSYST, Germany - DIAB, Spain -  FIBERTEX, Denmark – Gavazzi, Italy - MAP Yachting, France – MEL, Spain - SAERTEX GmbH & Co. KG, Germany, Sicomin, France - SKY, Hungary - Zoltek, Hungary

Three elements are mechanically joined to reach beams with a span of 75 m. The manufacturing process was infusion with double VAP membrane, avoiding the use of holes in the core and excess polymer.

The retractable roof function is described in this video: https://youtu.be/W1grwR6uSEY. Design and manufacturing of complex structural beams for the roof of the Real Madrid stadium. Three elements are mechanically joined to reach beams with a span of 75. The manufacturing process was infusion with double VAP membrane, avoiding the use of holes in the core and excess polymer. Critical parameters such as fiber linearity and core joints have been controlled in production to obtain elements with high compression resistance. Strategically, different reinforcements have been utilized in the design to meet the load case and assist in joining to the metallic elements. Finally, the lightweight composite beams allow simplification in the assembly operations on site as well as the simplification, weight and energy reduction of the displacement and elevation motors.

Main innovation:

• First, laminate innovation: laminates have been optimized to assure unidirectional carbon fiber linearity, for reinforcements equivalent thickness biaxial glass fiber is changed by biaxial carbon fiber. In this point configuration of non-crimp fabrics as well as the staggered between biaxial glass fiber and biaxial carbon fiber have been optimized and tested to achieve high compression laminate properties.
• Second, core innovation: monolithic 75 mm core is joined to a PET (or) balsa core to avoid variation in thickness. Different cores were joined and joints have been sealed to assure lineality due to thickness changes.
• Third, process innovation: to avoid excess resin weight, balsa core was sealed and finish core like holes and slots have been omitted, therefore for infusion VAP membrane was used on both faces of the sandwich to perform the infusion.

In the end, the final configurations achieved is a 7 mm carbon laminate on both faces of a 75 mm core. Joints with metallic diagonal joints to formalize the truss are made with monolithic carbon fiber with a thickness of 18 mm brackets.

Key benefits

• Weight reduction and simplification on site installation
• Excellent mechanical properties
• Environmental and energy benefit