Improvement of stress intensity factor determination by strain-gauge method

Prediction of the fatigue crack growth is based on the concept of fracture mechanics power parameter - stress intensity factor (SIF), obtained while analyzing elastic stresses in the stable crack under static loading. When calculating the service life and reliability of the metal structures elements using fracture mechanics parameters, knowledge of the formula to determine SIF for elements of various shapes, which have differences in the scheme of load application, and contain cracks of arbitrary orientation, is required. The results of experimental studies on improvement of stress intensity factor determination by the strain-gauge method are presented in this paper. It’s specified that distribution of stress ranges within a remarkable area near the crack tip is described by SIF.