| Abstract: | The strain energy density criterion is applied to predict fracture trajectories emanating from existing notch and crack front in nonisothermal environments. When temperature gradients are raised sufficiently high across a notch or crack, the resulting fracture trajectories are non-self-similar and curved in shape. Influence of mechanical loading is also considered in addition to stresses induced by thermal changes. Increase in the applied mechanical load tends to shift or restore the fracture trajectories toward the plane of notch or crack symmetry. The notch sharpness can be varied by adjusting the ration of the minor to major axes of an elliptical cavity. Narrowing the notch primarily increases the local intensity of the strain energy density function dW/dV that is inversely proportional to the radial distance measured from the focal point of the ellipse. This singular character of dW/dV prevails, in general, for all materials and loadings. Numerical results are obtained and displayed graphically for several examples involving fracture trajectory shapes that are not intuitively obvious. |
