DETERMINATION OF T-STRESS FOR THREE-POINT BENDING NOTCHED BEAMS

The T-stress which acts parallel to a crack, which corresponds to the constant term in the stress series at the crack tip, and its influence on the stress field can not be ignored. Three-point bending beam is generally used for testing fracture parameters in ordinary laboratories. Under this circumstance, T-stress at the crack tip must be determined first to see whether its value would influence the fracture parameters. In this paper, finite element program Abaqus is used to derive the T-stress for a three-point bending beam with a span-to-depth ratio of 4 and a single-edge notched beam subjected to pure bending. Thereafter, a general expression for T-stress of three-point bending beams of arbitrary span-to-depth ratio is presented based on St. Venant Principle. T-stress of three-point bending beams with span-to-depth ratio of 6, 8 and 10 is calculated using the proposed expression, and reasonable agreement is observed with the finite element analysis.