Stress intensity factors for cracks in grooved rolls used for hot-rolling

A procedure is described for the calculation of stress intensity factors for surface cracks in a section roll. Results are given in terms of the load acting on the roll and the average pressure acting on the roll/workpiece interface. It is noted that the load acting on the roll can be determined for individual cases by experimentally measuring the deformation of the roll stands: this obviates the necessity of relying on theoretical estimates of the roll/workpiece pressure. The stresses in the uncracked roll are determined using an axisymmetric finite element model. However, for the subsequent calculation of stress intensity factors the analysis is reduced to a plane strain model. It is shown that it may not be necessary to carry out finite element stress analyses on cracked rolls to determine stress intensity factors.