Filament-Wound Material Characterization

For typical filament winding applications, the fiber reinforcement provides the stiffness and strength required to maintain structural integrity. Thus, material characterization for filament wound structures focuses on characterizing the fiber dominated stiffness and strength properties of the composite. The stiffness of fiber reinforced plastics (FRPs), in the fiber direction, is dominated by the fiber stiffness characteristics. The strength will be influenced by a number of factors, however, and not all of them are related to the fiber, including  

In fact, the strength variability of a given fiber-resin combination may be significantly different from the strength variability of a different combination of the same fiber with another resin system [35]. This is particularly the case when environmental and fatigue loading (long-term durability) are considered. 

Fiber-reinforced plastics have varying degrees of resistance to adverse environments such as moisture, alkali, acid, and other chemicals. The degree of resistance depends on the fiber-resin system. Moisture absorption and chemical infiltration will be different for different fiber-resin systems. The degradation of composite materials may result from several factors  

Loss of reinforcing fiber strength by stress-corrosion 

Loss of adhesion and interfacial bond strength from degradation of the fiber-matrix interface 

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This section discusses test methods applicable to filament wound structures. As discussed earlier, filament wound structures are primarily subjected to internal and/or external pressure that is resisted by the fiber. Greater attention is therefore given to fiber-dominated stiffness/strength-dominated material characterization. 

CA 83, 82252 (1975) [The system RFNA/ UDMH was examined in a rocket motor of lOOdaN thrust. The optimum pressure for this system was found to be 7 x 106 Pascals. At one atm the H2—02 flame was almost invisible, but under increased pressure a bright, bluish-white light was emitted because of a flame continuum. This flame continuum was concluded as being the emission from transient, excited species characterized by the nonequil state] Compatibility. 1) W.K. Boyd et al, Compatibility of Materials with Rocket Propellants and Oxidizers , DM C Mem 201, Battelle Mem Inst, Columbus, Contract AF 33 (615)-l 121 (1965) CA 67,23666 (1967) [UDMH compatibility data reported is summarized in Table 1. The compatibility data for UDMH/hydrazine (50/50 wt %) is summarized in Table 2. The explanation of the numeric evaluation code used in these tables for metals is presented in Table 3 for nonmetals in Table 4 2) M.J. Spanger T.J. Reinhart, Jr, Development of Filament-Wound Tankage for Rocket... 

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