JEC COMPOSITES MAGAZINE - Issue #69 - November/December 2011 - 47

so that objects can be bolted onto the plates (see Figure 9). When peel forces are present, the steel plate can be bolted through the Acrosoma® plate. In this case, an extra steel plate has to be bonded on the other side of the panel and bushings need to be inserted so that the force can be transferred to the Fig. 9: Steel plate interface other side. Interface with glass-epoxy laminate plates The glass-epoxy laminate plates are bonded on the panel. The thickness of the plates ranges from 3 to 20 mm. Applications include local reinforcement or introduction of point loads, spacer panels, connection panels with threaded Fig. 10: Glass-epoxy interface holes (see Figure 10).

bonding
Base structures The large frames above are developed as bases for the jig for the A350XWB leading edge. The total Fig. 12: Assembly jig length of this combination is 40 metres and its cumulated thermal expansion is 0.25 mm per 10°C and 10 metres. The construction was glued on steel plates on top and bottom. These plates have a vertical tolerance of +/0.5 mm (see Figure 13). Fig. 13: Base frames Figure 11 and Figure 12 show the calculated winding angle and thickness of a single layer as a function of the axial coordinate, respectively. The winding angle and the thickness are necessary to properly develop the finite element model of the booster (see Figure 13). n

cost reduction (see Figure 11). Assembly equipment The transportable assembly jig above was designed to assemble the outboard flap of the A350XWB. It weighs 1,700 kg, with a 0.45-mm deflection in the middle. With a temperature difference of 10°C, its thermal expansion is 0.25 mm over a length of 13 m (see Figure 12).

High-end applications
Several composite constructions have been designed, tested and built by the Acrosoma team over the past years, using the advanced technologies described in previous paragraphs. Composites are increasingly used as structural materials in critical components. Acrosoma NV has acquired a lot of experience in this area over the past two decades. This experience is a good basis to share industrial knowledge and develop some basic rules for replacing steel structures with composite structures. New structures need to answer to following basic rules: - Retaining all former properties, without any exception; - Providing at least one extra property; - No extra price; - Start-up in small series must be possible, because that is how the market reacts.
Fig. 11: Horizontal transport tool

Transportation equipment The HTT (Horizontal Transport Tool) transports and positions the wing cover of the A350XWB in the Stade and Illescas plants. The high stiffness (7 mm bending over 33 metres under a 2.8-ton load) and the extremely low weight of the structure (3.6 tons) results in a significant

No69 November - December 2011 / jec composites magazine

More information: www.acrosoma.com

References 1. Potluri, P., Kusak, E. & Reddy, T. : “Novel stitch-bonded sandwich composite structures.” Composite structures (2003): 251-259. 2. Lascoup, B., Aboura, Z., Khellil, K. & Benzeggagh, M. : “On the mechanical effect of stitch addition in sandwich panel.” Composites Science and Technology (2006): 1385-1398. 3. Lascoup, B., Aboura, Z., Khellil, K. & Benzeggagh, M. : “Stitching effect on static and dynamic behavior of sandwich structures.” Sandwich structures 7: Advancing with sandwich structures and materials (2005): 681-690. 4. Østergaard, R. C., Sørensen, B. F. & Brøndsted, P. : “Measurement of interface fracture toughness of sandwich structures under mixed mode loadings.” Journal of sandwich structures and materials (2007): 251-259.

Research & development

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JEC COMPOSITES MAGAZINE - Issue #69 - November/December 2011

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #69 - November/December 2011