Sandwich composite

Hillger, W. Ultrasonic imaging of defects in Sandwich Composites -from laboratory reseach to in-field inspections, 7 " ECNDT 1998, Copenhagen, Conf. Proc. 

Structural Sandwich Composites, MIL-HDBK-23A, US Supt. of Documents, GPO, 1974. 

For the high-performance or sandwich composites, repairs, when they are possible, are always much more delicate. However, race boats are currently repaired after damage. 

The prices of sandwich composite cores (Figure 2.15) range from 1 (reference) for balsa to 5 for the aramid honeycombs. 

Figure 2.15. Relative costs of various cores for sandwich composites...

Rohaceir, a closed-cell PMI foam developed by Rohm of Germany to be used as cores in lightweight sandwich composites for transport, has specific advantages ... 

The compression strength of the foam and honeycomb sandwich composites can be low. 

In a sandwich structure, the foam is used as the core with two skins of reinforced resin sheets firmly stuck on the foam to obtain high rigidity. The sandwich composite behaves as an I-beam see Figure 6.11. 

Figure 6.11. Schematic principle of a sandwich composite with a foamed core...

Seats made of sandwich composite with foamed core and thermoplastic skins. 

This rigid linear foam with closed cells was developed by ATC Chemicals Company to be used as the core in lightweight structural sandwich composites particularly intended for boatbuilding. SAN foams have ... 

Generally, the sandwich composites combine light weight, good flexural stiffness and good stress distribution without weak points. Tensile and compression properties, particularly punching, can be weak. 

Table 7.6 (after Neste) displays some calorific properties of plastic wastes compared to coal. The laminates and sandwich composites are handicapped by the low heat value and carbon content. Moreover, the laminates have a high ash content. 

The composite as a unique material normally refers to hybrid or mixed materials between dispersed filler or reinforcemenf in fhe form of fiber, powder, flake, etc. and the continuous matrix. The composite applied to manufacture the plate mainly belongs to the type of nonmefallic composite with both nonmetallic filler and mafrix, alfhough research work on composite plates with metal filler has been carried ouf. This research will not be specifically introduced here because no promising results have been reported so far. The other sandwiched composite plate consists of layered metals and thermal expanded graphite and was developed by Russian scientists [11] however, no technical details were released. 

Ulven, C. A. and Vaidya, U. K. Post-fire low velocity impact response of marine grade sandwich composites, Composites Part A 2006, 37, 997-1004. 

Lattimer, B. Y., Ouellette, J., and Sorathia, U. Large-scale fire resistance tests on sandwich composites. In Proceedings of the 60th SAMPE, Long Beach, CA, May, 2004. 

Epoxy-phenolic adhesives were developed primarily for bonding metal joints in high-temperature applications. Their first major application was to join major aircraft components. They are also commonly used for bonding glass, ceramics, and phenolic composites. Because of their relatively good flow properties, epoxy phenolics are also used for bonding honeycomb sandwich composites. 

Cost Effective Infusion of Sandwich Composites for Marine Applications, RP, Dec. 2003. 

The C-C, C-SiC, and Cu-clad-Mo plates were sliced into 2.54 cm x 1.27 cm x 0.25 cm pieces, and ultrasonically cleaned in acetone for 15 min. prior to brazing. Braze powders were mixed with glycerine in a viscous paste with dough-like consistency, and a small (-0.2 g) quantity of this paste was applied to the joint region between the composite and metal. The sandwiched composite/braze/metal structure was placed under -6.0 kPa pressure (2.0 N load) in a vacuum furnace which was heated to the brazing temperature (-20°C above Tl) under a pressure of 10 torr. After a 5 min. soak at the brazing temperature, the assembly was slowly cooled at a controlled rate ( 5°C per min.) to 400°C, followed by furnace cooling. 

Diamanti K, Soutis C, Hodgkinson JM. Lamb waves for the non-destructive inspection of monolithic and sandwich composite beams. Compos A 2005 36(2) 189—95. 

Arora H, Hooper PA, Dear JP. Dynamic response of full-scale sandwich composite structures subject to air-blast loading. Composites Part A 2011 42 1651—62. 

Gardner N, Wang Em, Kumar P, Shukla A. Blast mitigation in a sandwich composite using graded core and polyurea interlayer. Expt Mech 2012 52 119—33. 

Seaver M, Aktas E, Trickey ST. Quantitative detection of low energy impact damage in a sandwich composite wing. J Intell Mater Syst Struct 2010 21(3) 297—308. http // dx.doi.org/10.1177/1045389x09347020. 

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