*Theor.Appl.Fract.Mech.* **20**, 67-74, 1994

### MODE-I CRACK PROJECTION PROCEDURE USING

THE STRAIN ENERGY DENSITY CRITERION

F.D. Fischer¹ and F.G. Rammerstorfer²

¹Institute of Mechanics,

University of Mining and Metallurgy, Leoben, Austria

²Institute of Lightweight Structures and Aerospace
Engineering,

TU Wien,
Vienna, Austria

**Abstract** -
A practice used in linear elastic fracture mechanics is the projection of a
crack onta a plane normal to principal tensile stress axes for computing
the stress intensity factor K_{I}.
The minimum strain-energy criterion is applied for different crack
configurations with the introduction of a safety factor S_{i}
which is the ratio of the strian energy density factor of the projectec
crack and that of the original crack.
Numerous crack configurations are investigated to illustrate the degree
of conservativeness of the crack projection procedure.

(hjb,960710)