On the measurement of ceramic fracture toughness using single edge notched beams

The single edge notched beam (SENB) method is a popular method for measuring the fracture toughness of ceramics. However, standard 3-point or 4-point bend loading of notched beams is not always suitable, especially for small or micro specimens. Different test geometries may be necessary to meet different requirements of special specimens. Therefore a consistent theoretical analysis of different tests involving notched beams is essential for a better understanding of test results. Here a new approach is developed for calculating KIC from bending tests of notched beams, which is generally applicable to all bending beam configurations. The equations derived using this approach are simple in form and are accurate when compared with finite element simulation. This approach also provides a more intuitive understanding of the effect of notch geometry on measurements using this and other flexural methods.