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Abstract Experimental study of failure characteristics of rock containing flaw under cyclic loading is carried out by using similarity materials. The similarity materials are elaborately designed by cement mortar and filling materials to simulate rocks with hole，flexible filling，or rigid filling. The characteristics of rocks containing flaw for the low-cycle fatigue damage are observed；and the three stages of the irreversible uniaxial deformation process are presented. Different defects in rock-like materials have great influence on their fatigue life and initiation and propagation of fatigue cracks. Experimental results show that the uniaxial deformation can be divided into three stages：initial deformation stage，constant-speed deformation stage，and acceleration deformation stage. Fatigue cracks are prone to initiate and propagate on the interface of defective and basis materials，where stress is concentrated. Conclusion can be made that with the same load conditions and the same sizes of flaw，the greater diameter of the hole is，the shorter fatigue life of hole-defect specimen is. It is also found that the fatigue lives of rigid-filling specimens are the shortest；the hole specimens take the second place；flexible-filling specimens have the longest life.
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Received: 16 April 2009
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