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In this study, the effect of the magnetic field on the thermo-elastic response of a rotating non-uniform circular disk of functionally graded material (FGM) is investigated for both steady and transient states of temperature. A single second-order ordinary differential equation of motion was developed for an FGM disk and solved along with the boundary conditions using the finite-difference method (FDM). The steady-state and transient heat conduction equations were also solved using the finite-difference method. Numerical results were presented and discussed for an Al/Al2O3 FGM disk of exponentially varying material properties keeping Poisson’s ratio and magnetic permeability uniform. Displacement and stress components were analyzed by increasing the intensity of the magnetic field for different cases of steady and transient states of temperature. The analysis suggests that the magnetic field has a remarkable effect on the displacement and stress distributions. It is also found that, high intensity of the magnetic field changes the nature and location of maximum stress. The transient analysis of magneto-thermo-elastic field suggests that the increase in the intensity of magnetic field results in the increase in stress intensity near the outer region of the disk and maximum radial stress always exceeds maximum circumferential stress. The effects of inner and outer surface radius, thermal gradient between inner and outer surface, and the outer surface thickness were also analyzed in detail. It was found that, with the decrease in outer surface radius and thermal gradient between inner and outer surface, maximum circumferential stress becomes higher than the maximum radial stress. In addition, the soundness and accuracy of the solutions were verified with the results from the standard computational method and analytical solution.

Summary Unidirecitonal pre‐preg carbon fibers of ten peel plies were laid up at 0‐, 45‐, −45‐, and 45‐degree stacking sequences on a flat and smooth aluminum (Al) plate, and then carbonized electrospun polyacrylonitrile (PAN) nanofibers were placed on top of the last ply prior to vacuum curing in a vacuum oven. The PAN electrospun fibers were oxidized at 280°C in an ambient condition for 1 hr and then carbonized at 850°C for 1 hr in an argon (Ar) gas atmosphere. The resultant composite panels were cut into small pieces and subjected to a number of different characterization techniques. Thermal mechanical analysis (TMA) measurements clearly showed that significant reinforcement was achieved for the pre‐preg/carbonized PAN fiber composites because of the enhanced interfacial bonding between the PAN nanofibers and the matrix. Dynamic mechanical analysis (DMA) tests exhibited a shift of the glass transition temperature of the carbonized PAN nanofiber/composite, which may be helpful for high‐temperature applications of the present composites. A Raman spectroscopy peak around 897 cm−1 indicated formation of the γ‐phase of the carbonized PAN fibers. The highest stretching peak of the CH2 group was recognized within the range of 2,500–2,800 cm−1 for the carbonized fibers. The vibration peak of the CN group also appeared at 1,452 cm−1 spectrum. TMA determined the coefficient of thermal expansion (CTE), indicating an improvement in stability of the composite material, which can be useful for structural health monitoring (SHM) as well as lightning strikes and electromagnetic interference shielding applications of new carbon fiber composites.

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