Author(s)

C-S Huang & P Labossiere

Abstract

Stress singularities, stress intensities and fracture initiation at sharp reentrant corners in elastic plates in bending C-S. Huang and P. Labossiere Department of Mechanical Engineering, University of Washington, Seattle, USA Abstract We present an approach to correlate fracture initiation at sharp reentrant corners in elastic plates. The approach is based on a rigorous stress analysis and reveals the universal nature of the asymptotic elastic fields at a reentrant corner, specifically that the stresses are singular with magnitude scaled solely by stress intensities. In order to validate the approach, we consider a specific reentrant corner angle and material, namely a 90ocorner in PMMA for which we determine the order of the singularity and asymptotic stress and displacement fields. From full-field finite element analyses, we compute the corresponding stress intensities for a given far-field geometry and loading. Specimens are tested to failure, and although the measured data shows that the failure load varied with the comer size, the corresponding stress intensities do not, demonstrating their use as a means to correlate fracture initiation. 1 Introduction Founded on the existence of a universal singular stress field at sharp corners of the form [1,2]: OiJ = E Knr2n –1 f iJ (0), (1) n a fair amount of work has been performed to support the use of the corresponding critical stress intensities to correlate fracture initiation. In general, there are an infinite number of terms in the series, each corresponding to a specific deformation mode. Here 2-1are the orders of the stress singularities, fij

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