Uniaxial tensile tests have been pe1formed on single-edge-notched sandstone specimens. The specimens were loaded between cables to minimize restraint. The cable length was varied in order to study the effect of the stiffness of the test set-up. The tests were…
Uniaxial tensile tests have been pe1formed on single-edge-notched sandstone specimens. The specimens were loaded between cables to minimize restraint. The cable length was varied in order to study the effect of the stiffness of the test set-up. The tests were conducted under deformation control. Three types of control method were tested to investigate the effect of control system. A long distance microscope was employed to trace crack propagation and the location of crack tip. The results show that both the cable length and control method affect the crack stability. A newly developed control system based on the maximum deformation rate of the control L VDTs shows to be most successful to obtain stable test results. The advantage of the cable test is that the loading situation is clearly defined. With known location of the crack tip, high accuracy inverse analysis of softening properties becomes possible.