Truss core

The primary structural role of the face/core interface in sandwich construction is to transfer transverse shear stresses between faces and core. This condition stabilizes the faces against rupture or buckling away ftom the core. It also carries loads normally applied to the panel surface. They resist transverse shear and normal compressive and tensile stress resultants. For the most part, the faces and core that contain all plastics can be connected during a wet lay-up molding or, thereafter, by adhesive bonding. In some special cases, such as in a truss-core pipe. 

Wicks, N. and Hutchinson, J.W. (2004) Performance of sandwich plates with truss cores. Mechanics of Materials, 36, 739-751. 

Brogan, J., Walsh, K., 16 September 1980. Truss core panels. Patent US 4,223,053. The Boeing Company, Seatle, WA. 

The described 3DNCOW approach is also suitable for producing some relatively complex net-shaped preforms, such as I, T, II, H, Y, as well as integral truss core and pile structures. Examples of such structural shapes designed and manufactured by 3TEX, Inc., can be found in Mohamed et al. (2001, 2003, 2005), Mohamed and Wetzel (2006), and Bogdanovich et al. (2008). Specific directions of those efforts have been determined by the practical industrial and military market needs and resulted in a broad spectrum of manufactured composite products. 

Spacer preforms, such as truss core, double truss core... 

An interwoven triangular truss core with face sheets is shown in Figure 9.28. A double interwoven truss core with face sheets is shown in Figure 9.29. The integrally woven cells were made to reduce the delamination of the composite materials and to enable them to withstand multiple impacts. 

Figure 9.28 Triangular truss core (Courtesy of Bally Ribbon Mills).

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