IMPROVEMENT OF THE DIRECT METHOD TO DETERMINE STRESS INTENSITY FACTORS OF FOR WHEEL PAIR AXES

A direct method for determining the stress intensity factor for wheel pair axes is improved based on the introduction of criteria for evaluating the quality of the finite element grid. The theoretical position is used that the stress intensity factor completely determines the stress state level at points located near the crack tip. Using the finite element method, pictures of the stress-strain state of wheel pair axes with cracks and stress intensity factors calculated through stresses near the crack tip are obtained. It is shown that the stress intensity factor values are the same in the local zone. Sections of stable intensity factor values are obtained on the graphs, which means that the grid of finite elements is sufficiently accurate. The improved method has been tested on wheel pair axes.