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In the present work, an empirical approach based on a computational analysis is performed to study the shielding properties of epoxy/carbon fiber composites and epoxy/glass fiber composites incorporating lead nanoparticle (PbNPs) additives in the epoxy matrix. For this analysis, an MCNP5 model is developed for calculating the mass attenuation coefficients of the two fiber reinforced polymer (FRP) composites incorporating lead nanoparticles of different weight fractions. The model is verified and validated for different materials and different particle additives. Empirical correlations of the mass attenuation coefficient as a function of PbNPs weight fraction are developed and statistically analyzed. The results show that the mass attenuation coefficient increases as the weight fraction of lead nanoparticles increases up to a certain threshold (~15 wt%) beyond which the enhancement in the mass attenuation coefficient becomes negligible. Furthermore, statistical parameters of the developed correlations indicate that the correlations can accurately capture the behavior portrayed by the simulation data with acceptable root mean square error (RMSE) values.

A high-resolution, total variation diminishing (TVD) stable scheme is derived for scalar hyperbolic problems using the method of flux limiters. The scheme was constructed by combining the 1st-order upwind scheme and the 3rd-order quadratic upstream interpolation scheme (QUICK) using new flux limiter function. The new flux limiter function was established by imposing several conditions to ensure the TVD properties of the scheme. For temporal discretization, the theta method was used, and values for the parameter θ were chosen such that the scheme is unconditionally stable. Numerical results are presented for one-dimensional pure advection problems with smooth and discontinuous initial conditions and are compared to those of other known numerical schemes. The results show that the proposed numerical method is stable and of higher order than other common schemes.

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This study investigates the effects of two different parameters on the mechanical properties of carbon fiber-epoxy composites. The two addressed parameters are the composite’s exposure to gamma radiation with different doses, and the incorporation of lead nanoparticles with different weight percentages in the epoxy matrix. Unidirectional carbon fiber-epoxy composites are manufactured using the hand layup vacuum bagging process, and they are characterized by tensile tests and scanning electron microscope. The first part of the study entails fabricating composite laminates with different weight percentages of lead nanoparticles, namely, 0wt%, 1wt%, 2wt%, 3wt%, 4wt% and 5wt%. The results show that composites incorporating lead nanoparticles up to 3wt% exhibit monotonically improved tensile strength and Young’s modulus without compromising their ductility. Whereas, degradation of these mechanical properties is observed with increasing lead content beyond 3wt%. For the second part of the study, composite specimens are exposed to different doses of gamma radiation, namely, 0, 25, 50, 75 and 100 kGy. It is observed that the tensile strength, the modulus of toughness and the ductility of the composites improve for radiation exposures up to 25 kGy. However, radiation exposures higher than 25 kGy lead to deterioration in the tensile strength, modulus of toughness and Young’s modulus with negligible effect on the ductility.