Patent ID: 8688415
Filing Date: 2014-04-01
Classification: G06F

Abstract:
1. A computer implemented method for determining one or more stress intensity factors, the method comprising: defining one or more crack tip zones about one or more crack tips of one or more arbitrarily shaped cracks in a finite element model representation mesh of an arbitrarily shaped solid; constraining, by a computer, the one or more crack tip zones within a finite element model representation mesh of the arbitrarily shaped solid to provide one or more constrained crack tip zones, wherein constraining the one or more crack tip zones comprises generating one or more multi-point constraint equations and one or more crack tip zone stiffness values to define the one or more constrained crack tip zones; wherein the one or more multi-point constraint equations are a function of a square root of a ratio of a radial distance from the crack tip over two times pi; processing, by the computer, a combination of the finite element model representation mesh and the one or more constrained crack tip zones; and determining, by the computer, a stress intensity factor for each of the one or more arbitrarily shaped cracks, wherein an initial estimate of a ratio of a uniaxial stress for a first arbitrarily shaped crack over the stress intensity factor for the first arbitrarily shaped crack is equal to the reciprocal of the square root of the product of pi times a crack depth of the first arbitrarily shaped crack, the initial estimate being employed in the one or more multi-point constraint equations during a preliminary analysis run and, based on a result of the preliminary analysis run, a value for the uniaxial stress of the first arbitrarily shaped crack is updated.