Elastodynamic stress intensity factors of an interface finite-width crack. [Elastic layer over different material with crack at interface]
Many applications in industry utilize a layered elastic structure in which a relatively thin layer of one material is bonded to a much thicker substrate. Often the fabrication process is imperfect and cracks occur at the interface. This paper is concerned with the plane strain, time-harmonic problem of a single elastic layer of one material on a half space of a different material with a single crack at the interface. The derivation of the required Green's functions for dilational and rotational point sources in the uncracked layered half space are outlined here. These functions are used with the appropriate form of Green's integral theorem to derive the scattered field potentials for arbitrary incident fields in the cracked layered half space. These potentials are then used in turn to reduce the problem to a system of singular integral equations for determining the gradients of the crack opening displacements in the scattered field. The integral equations are analyzed to determine the crack tip singularity, which is found, in general, to be oscillatory, as it is in the corresponding static problem of an interface crack. For many material combinations of interest, however, the crack tip singularity in the stress field is one-half power, as in the case of a homogeneous material. In the numerical work of this work attention is restricted to this class of composites and the integral equations are solved numerically to determine the Mode I and Mode II stress intensity factors as a function of a dimensionless wave number for various ratios of crack length to layer depth. The results are presented in graphical form and are compared with previously published analyses.
- Research Organization:
- Lawrence Berkeley Lab., CA (USA)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 6554428
- Report Number(s):
- LBL-18051; CONF-840738-1; ON: DE84016908
- Resource Relation:
- Conference: Progress in quantitative NDE, San Diego, CA, USA, 8 Jul 1984; Other Information: Portions are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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