Static and vibration analysis of functionally graded gears

Abstract

In this study, static and vibration analyses of functionally graded gears (FGGs) have been performed using the FE-based numerical method. The gear body is divided into uniform thickness homogeneous sub-domains conforming to the gear tooth profile. Material properties vary in the radial direction according to power-law gradation with metal at the innermost and ceramic at the outermost surface. Three FG gear cases are studied, assuming the gradation for the entire body, radially outer half, and the outer quarter of the gear. Parameters like root stress, weight reduction, tooth stiffness, and natural frequencies of FG and bi-material gears are studied and presented with steel gear as a reference. For FGGs, root stress increases and the weight of the gear reduces with an increase in gradient index. It has been observed that the maximum difference in the fundamental frequencies of FGGs and steel gears is 12% compared to 25% for bi-metal gears.