Solid material fatigue testing method for e.g. concrete bar - by comparing energy transfer conditions for different characteristic applied energies

摘要

The procedure consists in applying to the material an energy having a first set of characteristics and in recovering the energy restored by the material. An energy having a second set of characteristics is then applied and the restored energy recovered. The energy transfer conditions in the material for both cases are then compared. The two energy applications may be made simultaneously or successively and the comparison made on restored energy levels, phase difference or form of restored energy. The applied energies may be of the same type, or of different type. For the case of mechanical energy applied to a parallelepipedal concrete bar, the energy is generated electrically by a function generator and is applied for each measurement to the bar at two points by a transducer. Energy is recovered at a number of points by a piezo-electric pickup which transforms the mechanical energy into an electrical signal. A central unit analyses and compares the received signals. If an electrical source of energy is used two electrical contacts are used to apply this energy to the material.