Adviser: Florin Bobaru Damage and failure in composite materials under dynamic loading has been extensively studied in experiments for several decades. Composite materials exhibit various damage and failure patterns under different loading rates, such as splitting and branching. Classical models cannot directly be applied to problems with discontinuous fields. A new nonlocal continuum model, pe...

In this paper, a method for quantitatively evaluating the T " integral, directly from the measured near-tip displacement ®eld in laboratory specimens made of metallic materials, is presented for the ®rst time. Following Okada and Atluri (Okada, H., Atluri, S.N., 1999. Further studies on the characteristics of the T " integral: plane stress stable crack propagation in ductile materials. Computat...

The thermoelectroelastic solution for an elliptic piezoelectric inclusion embedded in an in®nite matrix and its application to crack±inclusion problems are investigated in this paper. By combining the method of Stroh's formalism, the technique of conformal mapping, the concept of perturbation and the method of analytical continuation, a general analytical thermoelectroelastic solution for an el...

An integral transform technique is used to solve the elastodynamic problem of a crack of fixed length propagating at a constant speed at the interface of two bonded dissimilar orthotropic layers of equal thickness. Two cases of practical importance are investigated. Firstly, the lateral boundaries of the layers are clamped and displaced in equal and opposite directions to produce antiplane shea...

We have extended our earlier investigation of scattering from surface cracks. In particular, we have studied the change in the reflection coefficient of a Rayleigh wave incident on a half-penny shaped surface crack along with the corresponding change in the acoustic crack size estimates as the cracked sample is stressed to fracture. We have examined in this manner both cracks in annealed sample...

A two-dimensional, time-harmonic eddy-current problem is examined in which a uniform field is perturbed by a long, surface-breaking crack in a non-magnetic, conducting half-space. The crack is assumed to be ideal in the sense that it has infinitesimal opening and yet forms a perfect barrier to the passage of electric current. A solution is sought which is accurate both at high frequencies, at w...

This paper presents a single-domain boundary element method SDBEM for linear elastic fracture mechanics analysis in the 2D anisotropic bimaterial. In this formulation, the displacement integral equation is collocated on the uncracked boundary only, and the traction integral equation is collocated on one side of the crack surface only. The complete fundamental solution Green’s function for aniso...

For a reliable operation of structures and their components during exploitation period, it is crucial to monitor continuously or periodically check the integrity of structure. In the production and during exploitation, a certain amount of flaws can be encountered in any structure. It is important to determine how such flaws can influence the safety and reliability of the operation. Since fractu...

A newly developed computational approach is proposed in the paper for the analysis of multiple crack problems based on the eigen crack opening displacement (COD) boundary integral equations. The eigen COD particularly refers to a crack in an infinite domain under fictitious traction acting on the crack surface. With the concept of eigen COD, the multiple cracks in great number can be solved by ...