Modification of the Shear Lag Analysis for Determination of Elastic Modulus of Short-Fiber (or Whisker) Reinforced Metal Matrix Composites

Abstract

A major shortcoming of the original shear lag analysis is its inability to provide sufficiently accurate strengthening predictions when the fiber aspect ratio is small. This is due to its neglect of stress transfer across fiber ends and the stress concentrations that exist in the matrix regions near fiber ends. In this paper, a straightforward, yet rigorous, modification of the original shear lag analysis is presented by taking fiber end effects into account and to result in fully closed-form solutions. It is demonstrated that the modification not only results in a correct prediction of the modulus increases in the small aspect ratio regime when compared to finite element results, but is also able to correctly predict the values of interfaciat shear stresses and local stress variations in the matrix and fiber.