Composite strength properties

Matrix cracking in the SFC tests in the case of low modulus resins has been observed recently by Netravali et al. [19], who have concluded that the SFC technique is experimentally simple but analytically complex. It can be expected that composite strength properties can show different degrees of improvement on silane treatment than indicated by IFSS measurements by the SFC test. 

TIME. SERVICE LIFE, PROCESSING CONDITIONS Figure 5-7. Degradation in the composite strength property during service life. 

Table 15. Strength Properties of Phenolic—Carbon-Fiber Composites...

Fig. 5. The immediate effect of temperature on strength properties of clear wood, expressed as percentage of value at 20°C. Trends illustrated are composites from studies on three strength properties modulus of mpture in bending, tensile strength perpendicular to grain, and compressive strength parallel to grain. VariabiUty in reported results is illustrated by the width of the bands. MC = moisture content.

Proper reinforcement of rubber matrix using hllers can be achieved only if there exists adequate adhesion between the hller and the mbber. Rubber-mbber adhesion and rubber-hller adhesion both without and with adhesion promoters have been studied extensively [125-127]. Fiber-matrix adhesion in short fiber-rubber composites is always a field of extensive research. If the fibers are not bonded properly with the rubber matrix, fibers will shde past each other under tension deforming the matrix, thereby reducing the strength properties. In the case of short fiber-reinforced rubber composites, loads are not directly applied to the fibers, but are apphed to the matrix. To obtain a high-performance composite, the load must be effectively transferred to the fibers, which is possible only when the fiber-matrix interphase is sufficiently strong. In addition, the adhesion between the fiber and the matrix should be such that the failure occurs in the matrix rather than at the interphase [92]. 

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