Local compliance, stress concentrations and strength in orthotropic materials

Abstract

Reducing tensile stress concentrations at geometric discontinuities in composites by altering the neighboring structural compliance, and the possible influence on strength, are investigated. Compared with the reduction in stress concentration, results show that increases in strength when introducing auxiliary holes can be appreciable in highly orthotropic natural composites such as wood but minimal in man-made aerospace-type structural composites. Although stress concentration might be a measure of structural integrity, assuming that a specific value of a stress concentration factor necessarily leads to failure can be erroneous. A scheme for optimizing size and location of auxiliary holes to minimize stress concentrations is included.