No abstract

This study deals with stress analysis of annular rotating discs made of functionally graded materials (FGMs). Elasticity modulus and density of the discs are assumed to vary radially according to a power law function, but the material is of constant Poisson's ratio. A gradient parameter n is chosen between 0 and 1.0. When n = 0, the disc becomes a homogeneous isotropic material. Tangential and radial stress distributions and displacements on the disc are investigated for various gradient parameters n by means of the diverse elasticity modulus and density by using analytical and numerical solutions. Finally, a homogenous tangential stress distribution and the lowest radial stresses along the radius of a rotating disc are approximately obtained for the gradient parameter n = 1.0 compared with the homogeneous, isotropic case n = 0. This means that a disc made of FGMs has the capability of higher angular rotations compared with the homogeneous isotropic disc.

No abstract

Table I), were chosen for impact testing. The impact energy was gradually increased until complete perforation took place, and an energy profiling method (EPM) was used to identify the perforation thresholds of composites. The damaged samples were visually inspected. The images of the several samples subjected to various impact energies were registered and used for comparison and identifying damage mechanisms. The perforation thresholds for [0/ 90/645] s aramid/glass and aramid/carbon laminates were found to be approximately 5% higher than those for their counterparts with the [0/0/90/90] s stacking sequence.

No abstract