Breviary Technical Ceramics



 3-point Bending Test

The test jig consists of two parallel supports for the sample and a single loading pin in the middle, between the supports, where the force is introduced. The support pins must be mounted in such a way that they can rotate freely on their axes in order to minimise the influence of friction on the measurement. One of the supports must also be able to rotate about an axis perpendicular to this and parallel to the axes of the sample so that the test piece can align itself when under stress. The loading pin must also possess similar rotational axes in order to ensure the uniform application of force on the test piece. The diameter of the support and loading pins and the distance between the centres of the supports (the loading span) can be taken from Table 33. The surface must be polished and free from burrs. The force is introduced perpendicularly to the test piece plane and/or the support plane. A typical set-up for such an instrument is shown in figure 212.

Figure 212: Schematic illustration of the 3-point bending test


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