Table 2-3. Material properties of fibers used in the verification problem.
 E-Glass Fiber Graphite Fiber (IM7)
 El (GPa) 72.4 263
 E2, E3 (GPa) 72.4 19
 G12, G13 (GPa) 30.2 27.6
 G23 (GPa) 30.2 27.6
 v12, V13 0.2 0.2
 V23 0.2 0.35
 an (106/Co) 5.0 -0.9
 a22, a33(10 6/Co) 5.0 7.2
 Tensile strength (MPa) 1,104 1,725


 The transversely isotropic properties of the glass and graphite fibers used in this

study are shown in Table 2-3 [26-27]. The material properties of fiber are assumed to be

independent to temperature changes.

 Estimation of Thermo-Elastic Constants

 The properties of a composite material depend on the constituent properties and

the microstructure of fiber and matrix layout and can be estimated by experimental

analysis and theoretical solutions. The experimental analysis is simple and trustworthy

but time consuming and expensive. Since the results are variable to fiber volume fraction,

constituent properties and fabrication process, the experimental analysis is required to

repeat the testing procedures. The theoretical and semi-empirical methods can be

effective when the composite material involves many variables which can affect

composite properties. However, the methods may not be reliable for component design

purpose and present difficulty in selecting a representative but tractable mathematical

model for some cases such as the transverse properties of some of the unidirectional

composites [26]. The mathematical solutions are unavailable as a simple form to predict

the transverse properties such as shear moduli G23 and Possion's ratio v23 [26]. In this