ON THE USE OF DISPLACEMENT EXTRAPOLATION TO OBTAIN CRACK-TIP SINGULAR STRESSES AND STRESS INTENSITY FACTORS

A displacement extrapolation method is developed which can be used to obtain crack tip singular stresses and stress intensity factors using only nodal displacements in the first layer of elements around the crack tip. A major benefit with this technique is that no analytical solutions are required. The triangular quarter-point elements are used around the crack tip to obtain nodal displacements with sufficient accuracy. Three geometries are considered: a single edge crack, a central crack and double edge crack. Two loading types are used: uniaxial tension and uniform pressure on the crack surface. Excellent results for singular stresses and displacements are obtained for Mode I crack problems.