Uniaxial fibers

Hashemi, S., Kinloch, A.J. and Williams, J.G. (1990b). The analysis of interlaminar fracture in uniaxial fiber polymer composites. Proc. Roy. Soc. Lond. A427, 173-199. 

Fig. 2.14 Fracture mechanism map for uniaxially fiber-reinforced ceramic composites under tensile loading.72...

The properties of the composite laminate are strongly dependent on the orientation sequence. Successive layers of uniaxial fibers are frequently oriented in appropriate directions so that the properties of low-pressure laminates will meet particular requirements. 

Samples were cut from 3-mm-thick sheets of the following 15-ply uniaxial fiber-reinforced composites 0.14-mm boron/6061 aluminum S-901 glass/NASA Resin 2 type AS graphite/NASA Resin 2 and 0.14-mm boron/5505 epoxy. The mechanical properties of these materials, which had been selected by the National Bureau of Standards, Boulder, Colorado, as candidates for low-temperature structural applications, have been discussed in detail by Schramm and Kasen [ ]. NBS supplied the samples for the thermal expansion measurement [" ] and calorimetric studies conducted at Battelle. 

Mechanical Properties. Naphthalate presence improves mechanical properties such as modulus and tensile strengths. Like PET, PEN can be oriented uniaxially (fiber) or biaxially (film and bottle) and heat-treated in a variety of ways. Consequently, mechanical properties vary over a wide range depending upon the exact fabrication parameters used. Furthermore, in films, mechanical properties may differ between the machine (MD) and transverse (TD) directions balanced films have very similar properties between the MD and the TD, whereas in... 

Fig. 4.3 Reflected light micrographs of polished composite specimens show the carbon fibers (white) and their orientation within the polymer matrix. Black regions are voids. In (A) various layers are oriented normal to one another while in (B) two uniaxially fiber tows are shown.

Spinning continuous uniaxial fiber bundle yams from electrospun fibers, demonstrated. 

The total result of crystallization and orientation is a measurable overall orientation in the fiber direction, uniaxially. Fibers are always birefringent the index of refraction in the axis direction (w//) is larger than the index crosswise (wx). The difference is the birefringence An = n// — n , and is a measure of fiber orientation. Orientation factors can be calculated from birefringence measurements (/ = 0 for random orientation, / = 1 for complete orientation), and are often split into crystalline orientation fc 1) and amorphous orientation (0 < < 1). 

The orientation of chopped fibers developed during flow/processing can strongly influence various properties of compounds, such as modulus and tensile strength. In 1974 Brody and Ward [79] described fiber orientation in uniaxial fiber filled composites using Hermans orientation factors [80 to 82] originally developed to measure polymer chain orientation in man-made fibers (see Fig. 2.5(a)). 

University, continuous uniaxial fiber bundle yarns are obtained by... 

Step-profile planar waveguide 12-20 Step-profile uniaxial fiber... 

Table 12-12 Step-profile uniaxial fiber. Parameters not defined in the table are given inside the back cover. Prime denotes differentiation with respect to argument. 

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