WHAT DOES THE PENDULUM HARDNESS TEST MEASURE

Various modes of energy absorption are considered as possible explanations for pendulum attenuation in the dynamic hardness testing of soda lime silica glass. It is concluded that the test gives little direct information about fracture processes, the major part of the energy absorption being accounted for by plastic flow in the solid as in the case of static hardness measurements. However, it is proposed that the effects of aqueous environments (which may be produced catalytically at the crack tip) can be observed by their effects on the yield stress and the onset of cracking of the glass. © 1979 Chapman and Hall Ltd.