Effect of geometry and poisson ratio on stress-intensity factors in a sen specimen under fixed-grip conditions

A finite-element analysis is performed to evaluate the influence of the geometrical configuration and of Poisson's ratio on the stress-intensity factor (SIF) prevailing in a single-edge-notch specimen (SEN) under fixed-grip conditions. It is found that the shorter the specimen and the longer the relative crack length, the greater the effect of geometry becomes. Moreover, even for very long specimens the SIF increasingly deviates from its value in a SEN specimen under uniform tensile stress as the crack length increases. Under constant remote displacement a variation in Poisson's ratio in the range of 0-0.5 results in a considerable increase of up to 33% in the SIF, for short specimens and long crack length, whereas, if under similar boundary conditions the remote applied load to the specimen is maintained constant, an increase in Poisson's ratio results in a sharp decrease in the SIF for short specimens and short crack length.